(Laconian: Split from Colin's Vette ZHZ review)
Quote from: HEMI666 on June 09, 2009, 09:44:25 AM
It's just like his hate-on for pushrod engines. The Chevy LSX and Chrysler Hemi, IMO, have proven that pushrods are every bit as capable as OHC.
It's an inherently lesser-performing technology objectively discussed
ad naseum both here and in automaker power train design departments the planet over.
It is no coincidence that there are no pushrod I4 or 6 cylinder engines anymore that aren't literally decades-old legacy leftovers (i.e., Chrysler's 3.8L).
Quote from: GoCougs on June 09, 2009, 09:57:15 AM
It is no coincidence that there are no pushrod I4 or 6 cylinder engines anymore that aren't literally decades-old legacy leftovers (i.e., Chrysler's 3.8L).
I think the GM 3.5-liter was new in 2004.
Quote from: GoCougs on June 09, 2009, 09:57:15 AM
It's an inherently lesser-performing technology objectively discussed ad naseum both here and in automaker power train design departments the planet over.
It is no coincidence that there are no pushrod I4 or 6 cylinder engines anymore that aren't literally decades-old legacy leftovers (i.e., Chrysler's 3.8L).
Pushrod V8s and V10s (in the Viper's case) are just as capable as their OHC counterparts, are lighter, and more compact.
:facepalm: Not this shit again...
Quote from: GoCougs on June 09, 2009, 09:42:59 AM
Sure I have a clue, and I've mentioned it myriad times; functional-wise, it's one dynamic structural member performing three disparate jobs (left spring, right spring, anti-roll bar) simultaneously and development-wise it's inherent variable rate and wheel travel issues, and tuning difficulty.
Only with expensive and complicated technology (i.e., ZR1's second-generation magnetic particle shocks) have GM engineers come close to combining the performance and livability of a high-performance coil suspension one would expect in a high-end sports car. My bet is that, should it ever come to be, the C7 will have coils.
If you have objective opinions to the contrary, try bucking up. Calling names simply makes you look like you can't technically challenge what has been written.
I've already gone over the tech ad nauseum. So now, it's more appropriate to note how fucking stupid you actually are.
There are no wheel travel issues, compared to coil springs in the application we're discussing (no Corvette or Porsche or BMW is going to have noticeably different suspension travel)
One side of the transverse leaf is no more affected by a bump on the other than the left side of a car with coil springs is affected by a bump on the right side. It also is lighter, has less unsprung weight than a coil spring, and by being mounted lower has a lower CG than a coil spring. it may do part of th ejob of the anti-roll bar, but that ends up beiung a side effect of the springing, rather than a separate job it has to do (i.e. it isn't working any harder in anti-roll than it doies as a simple spring. In fact, that's one of the benefits: it adds that ability for free, making the entire suspension more efficient and lighter)
As for being variable rate, so are the coils in a BMW M3 or a Porsche 911. That's not a hindrance at all.
The ONLY real disadvantage is in a race car situation, it's harder to swap out different rate springs for different tracks or different drivers. So in race car form, the Corvettes revert to coil-overs when the rules allow. (the other two disadvantages being cost of manufacture and in stigma from ignorant morons).
Quote from: GoCougs on June 09, 2009, 09:57:15 AM
It is no coincidence that there are no pushrod I4 or 6 cylinder engines anymore that aren't literally decades-old legacy leftovers (i.e., Chrysler's 3.8L).
Inline engines are a different animal than V engines. And inline 4s don't carry the issues of severely using up underhood real estate by making the heads slightly wider. they also are typically much smaller displacemetn engines that require, by virtue of being smaller displacement, more rpms to provide the what used to be race car levels of power that consumers demand these days, so the added breathing of 4 valve heads are not just a benefit, but a necessity. Larger displacement V engines, OTOH, have no need of that complexity to make useable power, and are better served by being physically smaller and less complex.
Hey, I'm completely dumbfounded as to how "I" created this thread (I did not)...
My bad, I was halfway through splitting the topic when the sky fell at work.
Quote from: ChrisV on June 09, 2009, 10:46:10 AM
I've already gone over the tech ad nauseum. So now, it's more appropriate to note how fucking stupid you actually are.
Hmmm...
Quote
There are no wheel travel issues, compared to coil springs in the application we're discussing (no Corvette or Porsche or BMW is going to have noticeably different suspension travel)
I noted this critique in the
design realm (i.e., constraint) of things.
Quote
One side of the transverse leaf is no more affected by a bump on the other than the left side of a car with coil springs is affected by a bump on the right side. It also is lighter, has less unsprung weight than a coil spring, and by being mounted lower has a lower CG than a coil spring. it may do part of th ejob of the anti-roll bar, but that ends up beiung a side effect of the springing, rather than a separate job it has to do (i.e. it isn't working any harder in anti-roll than it doies as a simple spring. In fact, that's one of the benefits: it adds that ability for free, making the entire suspension more efficient and lighter)
Unless you've redefined basic beam theory in the past 47 minutes, this wiki entry (http://en.wikipedia.org/wiki/Corvette_leaf_spring) plainly shows basic beam theory as it applies to the transverse leaf, and plainly illustrates the phenomenon I described; here's a cropped FEA analysis from said entry:
(http://img15.imageshack.us/img15/2671/713pxdeformedspringmode.jpg) (http://img15.imageshack.us/my.php?image=713pxdeformedspringmode.jpg)
Quote
As for being variable rate, so are the coils in a BMW M3 or a Porsche 911. That's not a hindrance at all.
The ONLY real disadvantage is in a race car situation, it's harder to swap out different rate springs for different tracks or different drivers. So in race car form, the Corvettes revert to coil-overs when the rules allow. (the other two disadvantages being cost of manufacture and in stigma from ignorant morons).
Variable rate wasn't the critique, it was the ability to get the desired range of variability owing to both the material and inherent design of the spring itself.
And you're being generous on the C6R
Quote
Inline engines are a different animal than V engines. And inline 4s don't carry the issues of severely using up underhood real estate by making the heads slightly wider. they also are typically much smaller displacemetn engines that require, by virtue of being smaller displacement, more rpms to provide the what used to be race car levels of power that consumers demand these days, so the added breathing of 4 valve heads are not just a benefit, but a necessity. Larger displacement V engines, OTOH, have no need of that complexity to make useable power, and are better served by being physically smaller and less complex.
No, they are not different animals. Neither do OHC engines "severely" use under hood space; 3.5+L DOHC V6s in such small vehicles as an IS350, Rav4, 370Z, G6, et al., both transverse an longitudinal configuration, plainly shows that it's a non issue.
Pushrod engines in the I4 and 6 cylinder are virtually non existent owing to the profoundly more competitive nature of these segments, exactly as you state; the fundamental engineering principles you implicitly acknowledge do not magically go away with cylinder count.
Further, t is also on coincidence that the only two automakers in the world that make appreciable numbers of gasoline pushrod engines are now in bankruptcy.
Quote from: Laconian on June 09, 2009, 11:32:35 AM
My bad, I was halfway through splitting the topic when the sky fell at work.
No problem, however I believe HEMI666 should've been the topic "starter" as he drew first blood in his out-of-the-blue pushrod apologism.
I'll put money on a 6.0L DOHC engine with variable valve timing would fit in the engine bay of a corvette and produce more power and have a broader torque curve
Really, if it's producing loads of power, or good fuel economy I don't see the point of this debate.
Quote from: r0tor on June 09, 2009, 12:30:02 PM
I'll put money on a 6.0L DOHC engine with variable valve timing would fit in the engine bay of a corvette and produce more power and have a broader torque curve
Would it fit under that really low hood?
Quote from: 2o6 on June 09, 2009, 01:06:08 PM
Really, if it's producing loads of power, or good fuel economy I don't see the point of this debate.
I agree. Looking at the results of the LS series of engines, what's the point of this argument? Lots of power in a light package with respectable fuel economy, what's wrong with that?
Quote from: HEMI666 on June 09, 2009, 01:06:45 PM
Would it fit under that really low hood?
if you can put a supercharger ontop of the current one and it fits - then yes and without a problem
Quote from: r0tor on June 09, 2009, 01:34:31 PM
if you can put a supercharger ontop of the current one and it fits - then yes and without a problem
The supercharger fits between the cylinder banks, not on top like on the GT500.
Quote from: TBR on June 09, 2009, 01:09:27 PM
I agree. Looking at the results of the LS series of engines, what's the point of this argument? Lots of power in a light package with respectable fuel economy, what's wrong with that?
Exactly. It's different methods of achieving the same thing.
Quote from: HEMI666 on June 09, 2009, 01:41:32 PM
The supercharger fits between the cylinder banks, not on top like on the GT500.
It can't - that's where the camshaft, lifters and pushrods live.
It sits on top of the block:
(http://img188.imageshack.us/img188/9402/ls9cutaway01.jpg) (http://img188.imageshack.us/my.php?image=ls9cutaway01.jpg)
Quote from: GoCougs on June 09, 2009, 01:46:08 PM
It can't - that's where the camshaft, lifters and pushrods live.
It sits on top of the block exactly as with the GT500's 5.4L:
My mistake. I thought it sat right in between the cylinder heads and barely increased the height of the engine at all.
Quote from: HEMI666 on June 09, 2009, 01:49:00 PM
My mistake. I thought it sat right in between the cylinder heads and barely increased the height of the engine at all.
Yeah, you guys do that a lot.
Quote from: GoCougs on June 09, 2009, 02:04:05 PM
Yeah, you guys do that a lot.
What's that supposed to mean?
Quote from: 2o6 on June 09, 2009, 02:08:44 PM
What's that supposed to mean?
It means "I will trumpet this mistake in this and every other OHV debate to suggest that everything my detractors say is just as inaccurate."
Quote from: r0tor on June 09, 2009, 01:34:31 PM
if you can put a supercharger ontop of the current one and it fits - then yes and without a problem
Its not just the height, it's the width. And it's not just the size, it's the price. Plus what does it matter? The new Vette makes like 450HP from 6 liters and gets good gas mileage. As much as I like to tech-snob, the LSx series of engines works. The 5.4L DOHC in the new Cobra needed a supercharger to make the same power. Within the realm of mass produced V8s you don't have that many making that kind of power. And DOHC heads are definitely bigger than OHV or even SOHC heads- to write that difference off as negligible is negligent IMO.
Can't we just compromise and have an OHC pushrod engine?
Quote from: ifcar on June 09, 2009, 02:13:56 PM
It means "I will trumpet this mistake in this and every other OHV debate to suggest that everything my detractors say is just as inaccurate."
First, the supercharger issue raised is independent of valve train configuration.
Second, it was an error indicative of rabid defenders such as ChrisV.
Third, you're generous in using the word "debate." The market decided this long ago.
I was ready to go order a Camaro SS until I found out it's ugly little secret. :(
Quote from: ifcar on June 09, 2009, 02:13:56 PM
It means "I will trumpet this mistake in this and every other OHV debate to suggest that everything my detractors say is just as inaccurate."
If so, that was very immature.
Quote from: Cobra93 on June 09, 2009, 02:55:05 PM
I was ready to go order a Camaro SS until I found out it's ugly little secret. :(
Oh, no, I'd definitely recommend that. I think it's one of the best vehicles GM has built in a very, very long time, and best of breed by a long shot.
I fail to see why people give a fuck about this shit. As others have pointed out, it works well so what's the big deal?
And the market decided the future of the rotary too. I'm just happy that Mazda ignored it just like Chevy with the pushrod.
Don't like them? Don't buy them.
Quote from: GoCougs on June 09, 2009, 12:22:49 PM
I noted this critique in the design realm (i.e., constraint) of things.
Unless you've redefined basic beam theory in the past 47 minutes, this wiki entry (http://en.wikipedia.org/wiki/Corvette_leaf_spring) plainly shows basic beam theory as it applies to the transverse leaf, and plainly illustrates the phenomenon I described; here's a cropped FEA analysis from said entry:
(http://img15.imageshack.us/img15/2671/713pxdeformedspringmode.jpg) (http://img15.imageshack.us/my.php?image=713pxdeformedspringmode.jpg)
And when you hit a bump with one side of a coil spring car, the car body moves up on that side, and transfers downward force to compress the other side's coil spring in almost exactly the same manner. Each side still affects the other. and if you make the coil spring stiffer, the problem gets worse. they end up doing the job of anti-roll just like the leaf you show, and to the same degree (which is barely any). The picture you show shows a spring deflection unattainable in an actual car (effectively that would equal pushing one side of the car down approx. a foot from static, which would make that side of the car actually a few inches UNDER the pavement.) in order to get ANY visible deflection of the opposite side.
Simply put, in the REAL world (on the street OR track) the deflection of the opposite side is at MOST barely measurable, and then only an issue if that side itself is on a billiard table smooth surface and the car body doesn't move even a fraction of an inch when hitting said bump.
QuoteVariable rate wasn't the critique, it was the ability to get the desired range of variability owing to both the material and inherent design of the spring itself.
Apparently not as much of a problem as you think as it's done quite well by both the factory and aftermarket.
No, they are not different animals. Neither do OHC engines "severely" use under hood space; 3.5+L DOHC V6s in such small vehicles as an IS350, Rav4, 370Z, G6, et al., both transverse an longitudinal configuration, plainly shows that it's a non issue.[/quote]
And I've seen a Ford 351cid V8 under the unmodified hood of a Focus, and an LS400 DOHC V8 under the hood of a PT Cruiser. Doesn't mean that they only take up as much room as the stock 4 cyl. If it can be done by a homebuilder, why can't big DOHC v8s fit in an economy car from the factory ALL the time?
Simply put, you can't rewrite physics on a V engine. A pushrod engine given the same displacement is physically smaller and more compact. Sometimes shorter, but always narrower and less tall. When differing displacements come into play, the difference is even more striking. My Lexus DOHC 4 liter V8 is the smallest and lightest of all mass produced DOHC V8s available, and it's physically much larger than the Ford small block V8 I'm replacing. the 5.0 fits in the Comet with room to spare for exhaust and the like. The shock towers will have to be entirely removed and new suspension created in order to accomodate the extra width of the lower displacement Lexus engine.
QuotePushrod engines in the I4 and 6 cylinder are virtually non existent owing to the profoundly more competitive nature of these segments, exactly as you state; the fundamental engineering principles you implicitly acknowledge do not magically go away with cylinder count.
Actually, they do, as the need to rev high to make usable power goes away as cubes climb. And as cubes climb, the need to be more compact and lighter for displacement goes up.
And of course, cost and complexity goes up pretty fast as cylinder count goes up in V configurations. While a DOHC I4 has twice as many cams and valves as a pushrod 4 cyl (like the old Iron Duke), a DOHC V engine has
4 times as many of each. So while teh friction inducing surfaces of a DOHC 4 is only slightly more than a pushrod or SOHC 4, the DOHC V engine has a LOT of new friction inducing surfaces in comparison, from 4 times as many cam gears, and much longer cam chains/belts and many more chain/belt tensioners, it has 4 times as many valve guide surfaces, 4 times as many cam followers riding on the camshafts, 4 times as many rockers or shims between the cam and valve, 4 times as many cam bearing surfaces, and only misses out on the 16 surfaces where the pushrod meets the lifter.
The DOHC will have one short cam belt/chain with one tensioner, which is about the same as a pushrod or SOHC 4. And the head, while wider, is not appreciably wider with the exhaust and intake factored in. it only has twice the bearing surfaces and valve guide surfaces in 4 valve form, but the loss of the pushrod friction surfaces is a more significant factor than in the V engine. So yes, the engineering principles do in fact change as cylinder count and layout change.
Quote
Further, t is also on coincidence that the only two automakers in the world that make appreciable numbers of gasoline pushrod engines are now in bankruptcy.
Sorry, but the pushrod engines have nothing to do with their bankruptcy. There are a LOT of factors that have contributed to that, from unions, to brand mismanagement, to piss poor quality control (and ironically, the highest quality is in those pushrod engines, themselves).
Quote from: r0tor on June 09, 2009, 12:30:02 PM
I'll put money on a 6.0L DOHC engine with variable valve timing would fit in the engine bay of a corvette and produce more power and have a broader torque curve
Pushrod engines can have Variable valve timing. GM already using it on a bunch of their engines. I think they plan to eventually make a 3V Pushrod (the thought was thrown around for the C6). All of the new Vortec 6.0 and 6.2 V8s GM puts in their trucks/SUVs have VVT. Pushrods just have a hard time making those ultra high REVs that OHC motors are more capable of.
I mean I'm sure everyone has seen the epic difference between the 5.0L pushrod Ford and the 4.6L OHC? I mean I know the 4.6 isn't the most compact of motors when it comes to OHC engines, but the difference in size is staggering.
(http://www.vorshlag.com/pictures/motor-4.6-4V-004.jpg)
Yea I bet a 6.0 DOHC setup would make more power than 6.0 OHV, but I really don't think it would fit very nicely in the corvette. I'd need to find some dimensions on some 6.0 DOHCs. But here is the 4.6 (I think this is not the SC version) XLR next to C6, same chassis.
(http://images.autobytel.com/view/aic/CADILLAC/XLR/cvt/usa_2008_cadillac_xlr_cvt_2_x_indrvreng_x.jpg)
(http://z.about.com/d/cars/1/7/f/9/1/ag_08vette_engine.jpg)
I'm sure there are some dimensional tweaks. But as you can see the relatively small northstar V8 kinda fills up the bill quite well.
Or look how CTS's engine bay looks with the V6 compared to the LS6 V8
(http://caddyinfo.com/wordpress/wp-content/uploads/2008/08/2005-cts-engine-compartment-after-quick-detail.jpg)
(http://www.roadfly.com/new-cars/wp-content/uploads/gallery/2004-cadillac-cts-v/cadillac-cts-v-engine.jpg)
I found pics of the shock mounts uncovered so it's easier to look at the passenger side shock mount and see where the engine sits.
There is a reason why the SBC is dropped into anything that has 4 wheels... sometimes ones with 2, lol.
Edit: just read your post ChrisV, haha yea if one thing GM did right it was those Pushrod Engines, lol.
Quote from: TBR on June 09, 2009, 01:09:27 PM
I agree. Looking at the results of the LS series of engines, what's the point of this argument? Lots of power in a light package with respectable fuel economy, what's wrong with that?
?
Quote from: 2o6 on June 09, 2009, 04:38:07 PM
You didn't type that?
No, I am trying to get Cougs or r0t0r to answer it.
Wow, that's simply too many responses to go tit-for-tat; so for that which comes to mind...
The FEA plot shows exaggerated movement (i.e., not to scale, hence the color code but hard to read the key on the right hand side). Yes, any conventional coil suspension will have "cross talk" but it's through a separate structural member (anti-roll bar). With the transverse leaf it's all the same member, plus it is dynamic, causing gods knows what harmonics.
As to the so-called "infamous" 4.6L vs. 5.0L comparison picture. Would the audience be similarly aghast with a comparison picture betwixt the size difference of a 5.0L and a Ford Flathead? Or how about between a Chrysler M-B 6.2L and 392 Hemi? The broken analogy with the 4.6L vs. 5.0L is that the Ford small block never came rated at more than about 240 hp (net) from the factory and was kind of a fragile engine at that, yet the 4.6L was not only leveraged from the beefier 5.4L that had to do duty in trucks, it had to be designed to eventually take the 390 hp (net) in the previous Cobra.
GM's pushrod engines are cheapo VVT - the do not phase intake relative to exhaust and to do not have variable lift. They simply phase the whole cam relative to the crank. Better than nothing but substantially off the mark. At least Chrysler with the Viper V10 went with a cam-in-cam approach to phase intake relative to exhaust (and both relative to the crank); it like GM's engines however doesn't have variable lift, either.
The reason why GM and Chrysler can mope along with their anachronisms is that there is precious little competition. The only real competition is the Toyota 5.7L, and I dare say that even with the recent GM (6.2L) and Dodge (revised 5.7L) , the Toyota 5.7L still wins the towing, acceleration and MPG categories in most any comparison people care to cite. I suspect however that many are hinging on the Corvette. The 911 with a physically smaller engine, less displacement, and despite being being a bigger, heavier car yet down on peak power is every bit the performer as that of the Corvette. Further, BMW's 5.0L V10, the 911 GT3's 3.7L F6, and M-B's 6.2L V8, utterly towers over the N/A versions of the LSx. The Corvette gets lucky because it gets to use a truck engine. Nothing new, really. And certainly nothing special.
Quote from: GoCougs on June 09, 2009, 07:33:27 PM
The reason why GM and Chrysler can mope along with their anachronisms is that there is precious little competition. The only real competition is the Toyota 5.7L, and I dare say that even with the recent GM (6.2L) and Dodge (revised 5.7L) , the Toyota 5.7L still wins the towing, acceleration and MPG categories in most any comparison people care to cite.
Oh really? Please find me these comparison tests where the six speed auto 5.7 Toyota beats the six speed auto 6.2 Chevy in towing, acceleration, AND MPG.
Oh wait I found a comparo.
http://www.edmunds.com/insideline/do/Drives/Comparos/articleId=147067
Except omg, they must have not gotten the memo because it appears that 6.2 beat the 5.7 through the 1/4 mile.
6.2 Chevy: 1/4 Mile (sec @ mph): 14.9 @ 94.1 mph
5.7 Toyota: 1/4 Mile (sec @ mph): 15.1 @ 91.7 mph
Well surely the 5.7 must have gotten better MPG from it's godly OHC's right?
Silverado: 14.2 mpg
Tundra: 13.6 mpg
Well so much for that.
So the Tundra only beats the Chevy in towing then and that's because the test Silverado came with the 3.42 gear ratio, compared to the Tundra with a final drive of 4.30.
Excuse me, I can't hear you over the sound of how awesome I am. (http://www.youtube.com/watch?v=8RG0meSRGZU&feature=related)
Yes, I was incorrect in thinking of the times per an engaged transfer case owing to major traction problems (here, last paragraph (http://www.trucktrend.com/roadtests/suv/163_0704_fullsize_truck_comparison/index.html)) to get 0-60 of 6 sec and 14.6 sec 1/4 mile times (more on that later).
First, the vehicle(s):
1.) Rear gear ratio is irrelevant, it's the final gear ratio that matters (c'mon, you know this):
The Silverado's gear ratios are:
4.04, 2.36, 1.52, 1.15, .85, .66
W/3.42:1 rear that equates to:
14.0, 8.1, 5.2, 3.9, 2.9, 2.3
The Tundra's gear ratios are:
3.33, 1.96, 1.35, 1.00, .728, .588
w/4.30:1 rear that equates to:
14.3, 8.4, 5.8, 4.3, 3.1, 2.5
As we can see the Tundra has only a slight advantage and not the substantial advantage you implied by simply comparing 3.42:1 vs. 4.30:1. I also remind everyone what we already know that the Tundra is the heavier vehicle (380 lbs per the Edmunds test).
2.) Recommended fuel for GM 6.2L is premium (kindly reference the Edmunds tests). Recommended fuel for the Tundra is regular.
Next, the tests:
1.) In the Edmunds test the Tundra is better at towing and got identical towing MPG.
2.) Tundra a wee bit slower unloaded but faster when pulling plus 10% better MPG:
http://www.trucktrend.com/roadtests/pickup/163_0902_2009_half_ton_truck_comparison/speclfications_and_data.html
3.) Tundra a wee bit slower unloaded, faster when pulling, and about tied on hill climb and again 10% better MPG:
http://special-reports.pickuptrucks.com/2008-light-duty-shoot-out.html
So, a heavier truck pulling more weight gets better MPG and has better acceleration points to traction issues for the Tundra when unloaded, and feeds right back into the very article posted.
LOL - so, we've covered push rods, leaf springs and the Tundra; what other hot-button issue pray tell is next...
All this angst and energy. I think it's good for you guys.
Quote from: GoCougs on June 09, 2009, 10:32:32 PM
LOL - so, we've covered push rods, leaf springs and the Tundra; what other hot-button issue pray tell is next...
All this angst and energy. I think it's good for you guys.
Let's see. Is the inferior pushrod engine that's put in the Corvette powering a sports car or not?
Is Obama working for the 'people'?
Quote from: Onslaught on June 09, 2009, 10:36:50 PM
Let's see. Is the inferior pushrod engine that's put in the Corvette powering a sports car or not?
How dare you: IT'S A GT NOT A SPORTS CAR.
Quote from: GoCougs on June 09, 2009, 10:45:10 PM
How dare you: IT'S A GT NOT A SPORTS CAR.
Egads! A manual Corvette convertible is certainly a sports car!
:popcorn: This is better than the Ridgeline debates!
Yeah, and the Titan, too.
Yeah, this does feel like the Octagon.
Quote from: GoCougs on June 09, 2009, 10:25:32 PM
Yes, I was incorrect in thinking of the times per an engaged transfer case owing to major traction problems (here, last paragraph (http://www.trucktrend.com/roadtests/suv/163_0704_fullsize_truck_comparison/index.html)) to get 0-60 of 6 sec and 14.6 sec 1/4 mile times (more on that later).
First, the vehicle(s):
1.) Rear gear ratio is irrelevant, it's the final gear ratio that matters (c'mon, you know this):
The Silverado's gear ratios are:
4.04, 2.36, 1.52, 1.15, .85, .66
W/3.42:1 rear that equates to:
14.0, 8.1, 5.2, 3.9, 2.9, 2.3
The Tundra's gear ratios are:
3.33, 1.96, 1.35, 1.00, .728, .588
w/4.30:1 rear that equates to:
14.3, 8.4, 5.8, 4.3, 3.1, 2.5
As we can see the Tundra has only a slight advantage and not the substantial advantage you implied by simply comparing 3.42:1 vs. 4.30:1. I also remind everyone what we already know that the Tundra is the heavier vehicle (380 lbs per the Edmunds test).
2.) Recommended fuel for GM 6.2L is premium (kindly reference the Edmunds tests). Recommended fuel for the Tundra is regular.
Next, the tests:
1.) In the Edmunds test the Tundra is better at towing and got identical towing MPG.
2.) Tundra a wee bit slower unloaded but faster when pulling plus 10% better MPG:
http://www.trucktrend.com/roadtests/pickup/163_0902_2009_half_ton_truck_comparison/speclfications_and_data.html
3.) Tundra a wee bit slower unloaded, faster when pulling, and about tied on hill climb and again 10% better MPG:
http://special-reports.pickuptrucks.com/2008-light-duty-shoot-out.html
So, a heavier truck pulling more weight gets better MPG and has better acceleration points to traction issues for the Tundra when unloaded, and feeds right back into the very article posted.
ET is a better measure of traction. Trap speed is a better measure of power. The GMC cars consistantly post faster trap speeds than the Tundra.
Anyway the Chevy runs the same part time 4WD system the Tundra does, so it's not like the GM's are getting an AWD launch.
The gearing difference is a big deal despite what you say, as much as over 10% in some gears (important gears like 3rd). The 300 pound weight difference is less than a 5% difference. In the very same tests you posted, it looks like the GM cars are the ones having trouble getting off the line (not the Toyota as you imply), with the GM's posting better passing times and trap speeds once underway.
In the first test (well first article as they really both refer to the same test) you see that the overall 0-60 loaded times are faster for the Toyota, but the GM's are faster from 40-60mph while loaded.
In the next test you'll see while the Tundra has a better elapsed time, both GM trucks post better trap speeds. Not consistant with your theory of traction issues for the Tundra.
In the end we have one test (yes both your articles actually refer to the event covered by different sources) where the Tundra won in fuel efficiency and another where the GM won. You could only conclude that gas mileage comparisons are mixed. Plus that test mentioned one major inconsistency. The Tundra was the only car fully broken in with 8000 miles on the clock, the rest of the field had only around 1000 miles on the clock. The Tundra usually isn't such a stand out in fuel economy in other tests. Loaded performance could only be described as mixed as the Toyota has better ET's but the GM's consistantly pulls better trap speeds. What isn't mixed is unloaded performance as the GM's trounces the Toyota both on ET and trap speed. Plus the 6.2 only recommends premium for max power and it's fine to run on regular. Considering the decent margin that the 6.2 destroys the 5.7 at the 1/4 mile trap speed, I wouldn't be surprised if the 6.2 still manages to out perform the 5.7 even on regular.
Quote from: Sigma Projects on June 09, 2009, 04:21:48 PM
Pushrods just have a hard time making those ultra high REVs that OHC motors are more capable of.
That is not true.
NASCAR teams are still running them, and turning up to 15,000 rpms.
Top Fuel dragsters are not allowed to run OHC engines, and they are turning out over 5,000 horses and 15,000 rpms.
The stock HEMI engine can turn 6,200 rpms. While that is not super high, its operating range is over the entire "safe" zone beneath the "redline."
Quote from: hounddog on June 10, 2009, 12:17:27 AM
That is not true.
NASCAR teams are still running them, and turning up to 15,000 rpms.
Top Fuel dragsters are not allowed to run OHC engines, and they are turning out over 5,000 horses and 15,000 rpms.
The stock HEMI engine can turn 6,200 rpms. While that is not super high, its operating range is over the entire "safe" zone beneath the "redline."
I've seen a new stock internal HEMI engine in Hot Rod magazine post nearly 500 hp with long tube headers, stage 3 camshaft and an engine controller at over 7000 rpm.
Quote from: hounddog on June 10, 2009, 12:17:27 AM
NASCAR teams are still running them, and turning up to 15,000 rpms.
10,000 at the most.... and my street car car hit that
Quote from: Sigma Projects on June 09, 2009, 04:21:48 PM
Or look how CTS's engine bay looks with the V6 compared to the LS6 V8
I found pics of the shock mounts uncovered so it's easier to look at the passenger side shock mount and see where the engine sits.
There is a reason why the SBC is dropped into anything that has 4 wheels... sometimes ones with 2, lol.
Edit: just read your post ChrisV, haha yea if one thing GM did right it was those Pushrod Engines, lol.
a Mercedes C-Class is smaller then the last gen CTS-V and they fit a 6.3L V8 in it without problems and it weighed less and had more power and torque... -yawn-
mercedes also drops a 6.oL V12 with turboz into a car with dimensions almost identical to the corvette -shrug-
well sure in racing yea. I just meant in general for modders that it's usually a bit harder for pushrod guys to spin the revs than the OHC guys, not that it's undoable. I know the LS7 was designed to rev to 8K RPMs from the factory, but doesn't because of the cam profiles and the intake flow rates.
I also love boosted pushrod motors :devil:
Go Cougs, i don't quite get your point, I'm not that familiar with those other motors. I'm just talking about the huge size difference between the 5.0 and the 4.6, it's a great example of the size difference. And I thought there were plenty of great 5.0 pushrods drag racing and doing well?
Ok, let me ask you something. Which would you take? An "anchor of a motor" pushrod LS7 with 505hp/470tq or a larger, longer, heavier and more complicated DOHC V10 from the m5 that makes 507hp/384tq to be the engine in the Z06? Or what about a LS6 with 405hp/400tq vs the larger heavier V8 in the M3 that makes 414hp/295tq?
I mean the BMW engines are great, they have great appeal. But just as performance figures the LS motors are superior. They're lighter, more compact and produce more power. I mean yea not as smooth or for audiophiles I'm sure they would prefer the higher revving sound of the BMW motors. But just strictly talking performance you surely can see the benefits of GM's pushrods right?
Not saying it's better per say, just that it has its performance advantages.
Quote from: r0tor on June 10, 2009, 06:00:20 AM
a Mercedes C-Class is smaller then the last gen CTS-V and they fit a 6.3L V8 in it without problems and it weighed less and had more power and torque... -yawn-
mercedes also drops a 6.oL V12 with turboz into a car with dimensions almost identical to the corvette -shrug-
So comparing two overall different cars? Are you talking about the CTS-V that had the LS6? The 5.7 liter? And then compare i'm sure a very much so larger 6.2L engine? I don't know the interior space of the C-class and what could fit nor what they could do to keep the overall weight of the car less than the CTS-V. But just talking about engines.
Edit: I did some reading and it's a very nice motor, weighing around 453lbs, it would be comparable to a LS7 7.0L. The pushrod similar displacement is the L92 or LS3 at 6.2L and that weighs 402lbs and 414lbs. The LS6 is an older motor and weighs a lot more than the newer LS motors and the same goes for the MB motors as the newer 6.2L weight I referenced was after extensive weight reduction.
Quote from: Sigma Projects on June 10, 2009, 06:12:36 AM
Or what about a LS6 with 405hp/400tq vs the larger heavier V8 in the M3 that makes 414hp/295tq?
last i checked, the two engines are within a few pounds of each other
Quote from: Sigma Projects on June 10, 2009, 06:15:08 AM
So comparing two overall different cars? Are you talking about the CTS-V that had the LS6? The 5.7 liter? And then compare i'm sure a very much so larger 6.2L engine? I don't know the interior space of the C-class and what could fit nor what they could do to keep the overall weight of the car less than the CTS-V. But just talking about engines.
you just compared a 6.0L to a 4.0L V8
oops sorry should have LS3 for the M3 comparsion. The LS3 is almost 50lbs lighter than the LS6.
I put in an edit in my above post.
"Edit: I did some reading and it's a very nice motor, weighing around 453lbs, it would be comparable to a LS7 7.0L. The pushrod similar displacement is the L92 or LS3 at 6.2L and that weighs 402lbs and 414lbs. The LS6 is an older motor and weighs a lot more than the newer LS motors and the same goes for the MB motors as the newer 6.2L weight I referenced was after extensive weight reduction."
edit: Oh and I meant that because you're comparing an older 5.7L to a new 6.2L. Well yea of course it's going to have more power, but it's not fair to compare old with new like that. The 6.2L should be compared more with the LS7 in terms of new tech and weight.
Quote from: r0tor on June 10, 2009, 06:00:20 AM
a Mercedes C-Class is smaller then the last gen CTS-V and they fit a 6.3L V8 in it without problems and it weighed less and had more power and torque... -yawn-
mercedes also drops a 6.oL V12 with turboz into a car with dimensions almost identical to the corvette -shrug-
And I've seen a 478 cubic inch Hemi in a Austin Healy Sprite. Let's not talk about what CAN be stuffed where if someone feels like it.
(http://www.modifiedhealeys.org/Photos/126Marian/Marian1.JPG)
(http://www.modifiedhealeys.org/Photos/126Marian/Marian2.JPG)
The point still stands: the LS engine is physically smaller, lighter, less complex and less expensive, yet puts out more power, reliably.
This is sitting in my garage right now:
(http://home.comcast.net/~cvetters3/engine1.jpg)
Like the DOHC 4.4 liter I have in my 740iL, I know exactly how big it is and where it fits. I have to, becasue I'm trying to put it in a location that the phyically smaller, but larger displacement pushrod V8 already sits.
I don't sit around reading magazines and do mental engineering. I work with these things directly, hands on.
the 6.3L AMG engine (actually 6.2L in displacement) also weighs in at 439 pounds which is what the LS2/6/7 weighs giver or take a few pounds here and there
i'm sick of the "oh pushrod engines are more powerful, have more torque, are lighter, are smaller, and rule the world" bullshit because given equal displacement engines its pretty easy to prove that they aren't more powerful, don't produce more torque, and aren't lighter. Size is harder to prove but I wouldn't doubt the mercedes engine is any bigger physically either looking at the applications its packaged in.
Thank you ChrisV, I too am putting in a larger engine with smaller displacement than compared to another guy who put in a LS1 into the same car and fits just as well as my 3.5L and actually fits I think easier than my 3.5L.
edit: here are some dimensions on some GM pushrods http://paceperformance.com/index.asp?PageAction=Custom&ID=586 I believe when I looked at the M3's V8 length it was about an inch longer than the LS1/LS6
Quote from: Cobra93 on June 09, 2009, 02:55:05 PM
I was ready to go order a Camaro SS until I found out it's ugly little secret. :(
Quote from: GoCougs on June 09, 2009, 03:33:49 PM
Oh, no, I'd definitely recommend that. I think it's one of the best vehicles GM has built in a very, very long time, and best of breed by a long shot.
Maybe, I could swap in one of those "superior" Northstars for the antiquated pushrod motor. That would surely be a vast improvement, no?
maybe after GM scraps the current northstar and works on a newer design. I think last time I read that the current northstar design is just too ancient and to make more power out of it will cost too much or something like that so they wanted to start from scratch again on the northstar. But that's just what I remember.
Quote from: 565 on June 09, 2009, 11:45:55 PM
ET is a better measure of traction. Trap speed is a better measure of power. The GMC cars consistantly post faster trap speeds than the Tundra.
Anyway the Chevy runs the same part time 4WD system the Tundra does, so it's not like the GM's are getting an AWD launch.
The gearing difference is a big deal despite what you say, as much as over 10% in some gears (important gears like 3rd). The 300 pound weight difference is less than a 5% difference. In the very same tests you posted, it looks like the GM cars are the ones having trouble getting off the line (not the Toyota as you imply), with the GM's posting better passing times and trap speeds once underway.
In the first test (well first article as they really both refer to the same test) you see that the overall 0-60 loaded times are faster for the Toyota, but the GM's are faster from 40-60mph while loaded.
In the next test you'll see while the Tundra has a better elapsed time, both GM trucks post better trap speeds. Not consistant with your theory of traction issues for the Tundra.
In the end we have one test (yes both your articles actually refer to the event covered by different sources) where the Tundra won in fuel efficiency and another where the GM won. You could only conclude that gas mileage comparisons are mixed. Plus that test mentioned one major inconsistency. The Tundra was the only car fully broken in with 8000 miles on the clock, the rest of the field had only around 1000 miles on the clock. The Tundra usually isn't such a stand out in fuel economy in other tests. Loaded performance could only be described as mixed as the Toyota has better ET's but the GM's consistantly pulls better trap speeds. What isn't mixed is unloaded performance as the GM's trounces the Toyota both on ET and trap speed. Plus the 6.2 only recommends premium for max power and it's fine to run on regular. Considering the decent margin that the 6.2 destroys the 5.7 at the 1/4 mile trap speed, I wouldn't be surprised if the 6.2 still manages to out perform the 5.7 even on regular.
No - gearing difference not a big deal for those tests, as they reached a max of 60 mph. Again, the details, using a max engine speed of 5800 rpm, speed in gears:
Silverado
1st = 38 mph
2nd = 66 mph
Tundra
1st = 37 mph
2nd = 64 mph
Until I see objective proof to the contrary, I plainly see a truck (Tundra) that has traction issues. Plus, it's a smaller displacement engine that runs on regular fuel. I remained thoroughly unconvinced that the 6.2L is as good or better.
Quote from: ChrisV on June 10, 2009, 06:59:00 AM
And I've seen a 478 cubic inch Hemi in a Austin Healy Sprite. Let's not talk about what CAN be stuffed where if someone feels like it.
(http://www.modifiedhealeys.org/Photos/126Marian/Marian1.JPG)
(http://www.modifiedhealeys.org/Photos/126Marian/Marian2.JPG)
That is so painfully awesome it hurts my head just to think about it. I
want it.
Quote from: sportyaccordy on June 09, 2009, 02:36:45 PM
Its not just the height, it's the width. And it's not just the size, it's the price. Plus what does it matter? The new Vette makes like 450HP from 6 liters and gets good gas mileage. As much as I like to tech-snob, the LSx series of engines works. The 5.4L DOHC in the new Cobra needed a supercharger to make the same power. Within the realm of mass produced V8s you don't have that many making that kind of power. And DOHC heads are definitely bigger than OHV or even SOHC heads- to write that difference off as negligible is negligent IMO.
Last I checked the 6.3 liter vette engine makes 438hp, the 5.4 SC GT500 makes 540 hp. Seems like a good bit more our of the 5.4SC.
Quote from: r0tor on June 10, 2009, 07:06:53 AM
the 6.3L AMG engine (actually 6.2L in displacement) also weighs in at 439 pounds which is what the LS2/6/7 weighs giver or take a few pounds here and there
i'm sick of the "oh pushrod engines are more powerful, have more torque, are lighter, are smaller, and rule the world" bullshit because given equal displacement engines its pretty easy to prove that they aren't more powerful, don't produce more torque, and aren't lighter. Size is harder to prove but I wouldn't doubt the mercedes engine is any bigger physically either looking at the applications its packaged in.
You know I used to be a big fan of the 6.2, being as light as that claimed 199kg weight and pulling 507hp in the E63 AMG. However since then (from similar debates on other forums) two things came to light that don't allow this engine to be compared as favorably to the LS7 in real life as it does on paper.
First something seems a bit off with the 6.2 Merc weight claims of 199kg, while the much smaller displacement BMW V8 weighs 202kg. Now BMW aren't fools at making light engines. The thing about engine weight claims is that unless you pull it out of the car and stick it on the scale, it's hard to compare apples to apples. People have different ideas of what exactly fully dressed is, and I haven't actually seen an official claim for "fully dressed" for that 199kg figure, the official claim is "dry weight." Now whether the 6.2's dry weight is in the exact same state as GM's fully dressed claim, that is up to speculation.
Now the other thing that did become a black mark on the 6.2 is that despite claims of 507 hp for the 6.2 Mercedes and 505 hp the 7.0 LS7, there is actually a power gap between the engines. On real life Dynos, the 6.2 just plain doesn't put down as much power as the LS7. When you compare the collection of dyno runs, it just plain doesn't. And it's not like some tiny difference either, it's a pretty big deal. Obviously there are some sizable variations for engine output and dyno runs so we have to look at the range.
The Merc 6.2 has been dynoing in about the 380-420 range on Dynojet.
http://www.mbworld.org/forums/w211-amg/162875-my-e63-dyno-experience.html
http://www.mbworld.org/forums/w211-amg/162541-i-feel-dyno-coming.html
http://www.mbworld.org/forums/cls55-amg-cls63-amg-c219/176245-cls63-dyno-results.html
As you can see, these are Dynojet numbers, which are supposed to be the higher reading ones.
(http://img60.imageshack.us/img60/1150/4thgearpullslargejx2.jpg)
(http://www.dragtimes.com/images_dyno/9842-2007-Mercedes-Benz-E63%20AMG-Dyno.jpg)
I believe the highest recorded for a stock MB 6.2 was 428rwhp.
Compare those numbers to what the LS7 routinely puts down, in the 440 to 460 range on Dynojet.
http://forums.corvetteforum.com/c6-tech-performance/1236902-c6-z06-dyno-video-and-numbers.html?forum_id=101
http://forums.corvetteforum.com/c6-z06-discussion/1954824-stock-z06-dyno-graph.html
http://forums.corvetteforum.com/c6-tech-performance/1231115-2005-z06-dyno-numbers-working-with-exhaust.html?forum_id=101
The highest I've seen recorded was 488 from one particularly strong Z06.
http://forums.corvetteforum.com/c6-z06-discussion/1337820-just-dynod-the-new-z-480rwhp-stock.html?forum_id=100
Here are 3 superposed Z06 Dyno runs to give you a sense of the range the LS7 can put down.
(http://www.boostaholic.com/427z/two427zdynos.gif)
So looking at the range for the MB 6.2 380-428 (highest recorded) against the LS7 7.0 440-488 (highest recorded). We are looking at a huge gap here, around 60 rwhp hp of difference. Now you could try to claim that it's the manual in the Z06 that being more efficient, but that could really only account for a 20hp gap or so.
Actually here is a good comparison of a dyno from a automatic LS3 engine compared to a manual LS3, and the gap between the cars was 19Hp
http://www.dragtimes.com/blog/2008-chevrolet-corvette-ls3-dyno-results
Auto LS3 (this car had less than 30 miles on the clock, and really had no business being on a dyno in the first place)
(http://www.dragtimes.com/images_dyno/12823-2008-Chevrolet-Corvette-Dyno.jpg)
Manual LS3
(http://www.dragtimes.com/images_dyno/12824-2008-Chevrolet-Corvette-Dyno.jpg)
Also note that the 6.2 LS3's will put down around the 370-390 range, which is more comparable to what the 6.2 DOHC merc is putting down than the LS7 (as suggested by looking at paper stats).
Quote from: Sigma Projects on June 09, 2009, 04:21:48 PM
I mean I'm sure everyone has seen the epic difference between the 5.0L pushrod Ford and the 4.6L OHC? I mean I know the 4.6 isn't the most compact of motors when it comes to OHC engines, but the difference in size is staggering.
(http://www.vorshlag.com/pictures/motor-4.6-4V-004.jpg)
The motor on the right with its crappy 1/2" two bolt mains and paper thin walls in holding the cams in will self destuct above 400 hp. The most the factory ever got out of it was 245 hp.
The motor on the left has 6 bolt cross drilled mains with thick main bearings. The Al block will easily support 800-900 hp with forged internals. The mustang 4V had a lowest rating of 305 and certainly was capable of at least 100 more hp.
Guess what is the same about both engines in the pic? Both the 5.0 and the 4.6 4V fully dressed weigh the same (full mid 90s smog equipped).
A 3V mustang engine only comes in at 420 lbs.
Race 5.0s use and FRRP A6 block or something like a dart block, any regular 5.0 block is living on borrowed time over 400 hp.
WOW you guys are busy...
The 5.0L vs. 4.6L is as to the 5.0L vs. flat head. The 5.0L is larger than the flat head, yet it is more powerful and more robust (just as the 4.6L is larger yet more powerful and more robust WRT the 5.0).
The BMW V10, M-B 6.2L V8, Porsche 3.8L F6, et al., are all superior engines.
The correct Northstar/small block analogy should be 1990. In 2009 the Northstar is an ancient throwback, however, almost 20 years ago, it was superior to the 305/350 V8 of the time.
Quote from: 565 on June 10, 2009, 08:42:12 AM
Also note that the 6.2 LS3's will put down around the 370-390 range, which is more comparable to what the 6.2 DOHC merc is putting down than the LS7 (as suggested by looking at paper stats).
stock S63AMG chassis dyno on a dynopack (not overly optimistic dynojet)... the 6.3 engine at its highest factory potential. Also keep in mind, mecedes will be more worried about NVH then a corvette engineer would be, therefor the driveline components tend to be beefier and therefore have more inertial losses. Also, the benz has a torque converter to deal with :facepalm:. So in conclusion, its putting down the same numbers as a larger displacement 7.0L LS7 engine.
(http://i425.photobucket.com/albums/pp331/thinkabbott/goodrun_test2.jpg)
Anytime I see a chassis dyno I tune out. There are inherent issues with getting better than ~5% accuracy, and myriad times I've seen erroneous operation (as in, "a lighter drive shaft gave me 10 hp!"). The only proper comparison is via a stand-alone, water brake style engine dyno.
Further, the M-B 6.2L is luxury engine used in cars, vans and SUVs; the LS7 is a tapped out, very limited production sports car engine.
Quote from: r0tor on June 10, 2009, 08:53:20 AM
stock S63AMG chassis dyno on a dynopack (not overly optimistic dynojet)... the 6.3 engine at its highest factory potential. Also keep in mind, mecedes will be more worried about NVH then a corvette engineer would be, therefor the driveline components tend to be beefier and therefore have more inertial losses. Also, the benz has a torque converter to deal with :facepalm:. So in conclusion, its putting down the same numbers as a larger displacement 7.0L LS7 engine.
(http://i425.photobucket.com/albums/pp331/thinkabbott/goodrun_test2.jpg)
:facepalm:
This was that new "dynopack" dyno at DC performance wasn't it?
That Dyno reads notriously high.
http://forums.viperclub.org/srt10-srt10-coupe-discussions/626330-before-after-paxton-dyno.html
"If it was the same type as the
new Dyno that DC Performance is now using, then I would not have the same question because Dan Cragin said that
the new dyno produces numbers that are higher than a Dynojet. So, if possible, please indicate what kind of dyno was used. Thanks."
In case you are wondering Dan Cragin is the guy who actually owns DC performance, so straight from the horse's mouth.
Here is a realistic S63 AMG Dyno done by the same guys DC performance on their Dyno Jet. (probably the same car too)
http://www.dragtimes.com/2009-Mercedes-Benz-S63-AMG-Dyno-Results-Graphs-16625.html
(http://www.dragtimes.com/images_dyno/16625-2009-Mercedes-Benz-S63-AMG-Dyno.jpg)
Quote from: r0tor on June 10, 2009, 07:06:53 AM
the 6.3L AMG engine (actually 6.2L in displacement) also weighs in at 439 pounds which is what the LS2/6/7 weighs giver or take a few pounds here and there
i'm sick of the "oh pushrod engines are more powerful, have more torque, are lighter, are smaller, and rule the world" bullshit because given equal displacement engines its pretty easy to prove that they aren't more powerful, don't produce more torque, and aren't lighter. Size is harder to prove but I wouldn't doubt the mercedes engine is any bigger physically either looking at the applications its packaged in.
the mercedes engine, sitting outside the car, is physically bigger. As is teh lecxus engine i have sitting in my garage, and the measurements i took off the 4.4 liter BMW engine in my own car (thinking maybe i could use a version of it in my project instead of the Lexus).
You can call BS all you want, but until you do more than read a magazine and drive your rotary car around, you will continue to be wrong.
Oh, and do you have equal displacement V8s sitting around to determine and
gurantee which is lighter? or are you using V6s that in typical domestic form were cast iron engines, rather than aluminum, thus changing the comparison...
Quote from: SVT32V on June 10, 2009, 08:44:11 AM
The motor on the right with its crappy 1/2" two bolt mains and paper thin walls in holding the cams in will self destuct above 400 hp. The most the factory ever got out of it was 245 hp.
Actually, with Cleveland style heads, the factory rating was 290hp in my '70 BOSS 302. And they were capable of 8000 rpm in streetable form, much like the Chevy DZ302 of the same era.
Some have split blocks, but I've seen numerous SBFs putting out well over 400 hp reliably in supercharged form at 306 cid, and many stroked to almost 350 cid that are doing it routinely in NA form. and a My own 306 cid carbed version was a reliable daily driver and autocross engine for 5 years at nearly 400 hp. And that was with cast iron block and heads.
QuoteGuess what is the same about both engines in the pic? Both the 5.0 and the 4.6 4V fully dressed weigh the same (full mid 90s smog equipped).
A 3V mustang engine only comes in at 420 lbs.
Race 5.0s use and FRRP A6 block or something like a dart block, any regular 5.0 block is living on borrowed time over 400 hp.
Or you use an older, seasoned block from the late '60s/early 70s. ;)
And my cast iron block and head 306 (true 5.0) weighed in at 400 lbs ready to run. Would have been lighter with the aluminum heads. As it was, it fit in the RX7 with massive room to spare (the 4.6 doesn't).
The listed weights I've seen on the Mustang iron block SOHC 4.6s are well over 500 lbs ready to run. The all aluminum DOHC is still at about 500 lbs in this form, shipped:
(http://www.uship.com/static/e1823941-7d43-4a05-9.jpg)
A couple people in the V8 RX7 community have attempted to put in 4.6 mod motors in the cars, and they simply wouldn't fit between the strut towers, while my 306 fit like it was meant to be there:
(http://www.supercars.net/pitlane/pics/484414b.jpg)
Quote from: 565 on June 10, 2009, 09:07:39 AM
Here is a realistic S63 AMG Dyno done by the same guys DC performance on their Dyno Jet. (probably the same car too)
http://www.dragtimes.com/2009-Mercedes-Benz-S63-AMG-Dyno-Results-Graphs-16625.html
(http://www.dragtimes.com/images_dyno/16625-2009-Mercedes-Benz-S63-AMG-Dyno.jpg)
i call ultimate :facepalm: on that because the nimrods are overriding the SAE correction factor on a normally aspirated car
who the F cares about the 4.6L DOHC mustang engine? I mean really, its like using an elephant hemi motor as the size of a steriotypical pushrod engine
Modded motors are broken context - Ford never built a warrantied, smog-friendly 302/351 good for more than about 250 hp (net as already stated - about 300 gross as in the Boss 302). The engine was tapped in power and warrantability WRT to the retail market - just as the flat head eventually reached its peak in each, and was in turn itself replaced by the OHV.
Quote from: GoCougs on June 10, 2009, 09:45:36 AM
Modded motors are broken context - Ford never built a warrantied, smog-friendly 302/351 good for more than about 250 hp (net as already stated - about 300 gross as in the Boss 302). The engine was tapped in power and warrantability WRT to the retail market - just as the flat head eventually reached its peak in each, and was in turn itself replaced by the OHV.
Of course you are referring to the North American market, but for interest's sake you'll find the 268hp Falcon XR8 Sprint and GT variants of 1992, the 268hp Falcon GT of 1997, the 295hp Falcon TS50s from 1999-2001 and '01-'02 Falcon XR8s, and the 342ci 335hp TS50 and Pursuit variants of 2002.
Quote from: r0tor on June 10, 2009, 09:43:05 AM
i call ultimate :facepalm: on that because the nimrods are overriding the SAE correction factor on a normally aspirated car
:facepalm: :facepalm: :facepalm: :facepalm: :facepalm: :facepalm: :facepalm: :facepalm: :facepalm: :facepalm: :facepalm: :facepalm:
No they aren't, the SAE correction factors are correct.....
http://wahiduddin.net/calc/calc_cf.htm
http://www.silvercote.com/PDF/VaporPressureTempRH.pdf
Of course, we've also strayed into the Ford SB territory, where even the latest 5.0 heads can be bolted onto an early '60s 260 and vice versa. Ford didn't continually improve the SB the way GM did (with the exception of changing from a 5 bolt to a 6 bolt early in the 289 production run. The previous 221/260/early289s were 5 bolt bellhousing designs, and transmissions don't interchange). The LS shares precious little with the traditional SBC except layout.
What the Ford illustrates is how compact a larger displacement pushrod V8 can be vs even the smallest DOHC V8. Even in cast iron form, it was thus lighter than even the smallest aluminum mass production V8 in modern cars (I don't count exotic V8s like Ferraris, et al, due to the fact that they are seriously expensive and made in small numbers, and are not known for living reliably for many miles at a time)
i will conceed to there being am azing combination of weather effects that leads to a 1.00 CF... in any event, it is still putting out more power then any 6.3L OHV engine while weighing the same -shrug-
Quote from: ChrisV on June 10, 2009, 06:59:00 AM
Let's not talk about what CAN be stuffed where if someone feels like it.
Hmmmph...I saw a movie on Cinemax last night with that exact same tag line.
Quote from: ChrisV on June 10, 2009, 10:50:04 AM
What the Ford illustrates is how compact a larger displacement pushrod V8 can be vs even the smallest DOHC V8. Even in cast iron form, it was thus lighter than even the smallest aluminum mass production V8 in modern cars (I don't count exotic V8s like Ferraris, et al, due to the fact that they are seriously expensive and made in small numbers, and are not known for living reliably for many miles at a time)
The Ford 5.0 fully dressed for smog regulations of the mid 1990s was over 500 lbs. You can't compare your carbed smogless aftermarket modified engine to a factory engine that has to pass smog and have a warranty. Apples and oranges.
Quote from: ChrisV on June 10, 2009, 09:40:13 AM
Actually, with Cleveland style heads, the factory rating was 290hp in my '70 BOSS 302. And they were capable of 8000 rpm in streetable form, much like the Chevy DZ302 of the same era.
Of course there were wonderful examples of small block fords but we are talking about the ubiquitous 5.0 of the 90s that was in the pictures.
Some have split blocks, but I've seen numerous SBFs putting out well over 400 hp reliably in supercharged form at 306 cid, and many stroked to almost 350 cid that are doing it routinely in NA form. and a My own 306 cid carbed version was a reliable daily driver and autocross engine for 5 years at nearly 400 hp. And that was with cast iron block and heads.
Yup, some get lucky but Ford could never warranty a 390 hp 5.0 like the '03 cobra.
And my cast iron block and head 306 (true 5.0) weighed in at 400 lbs ready to run. Would have been lighter with the aluminum heads. As it was, it fit in the RX7 with massive room to spare (the 4.6 doesn't).
Yeah, good luck smog certifying it as a production smog passing car.
The listed weights I've seen on the Mustang iron block SOHC 4.6s are well over 500 lbs ready to run. The all aluminum DOHC is still at about 500 lbs in this form, shipped:
The aluminum 3V weighs 420lbs fully dressed.
A couple people in the V8 RX7 community have attempted to put in 4.6 mod motors in the cars, and they simply wouldn't fit between the strut towers, while my 306 fit like it was meant to be there:
The 5.0 is much narrower than the 4.6, no argument there.
Quote from: omicron on June 10, 2009, 10:08:11 AM
Of course you are referring to the North American market, but for interest's sake you'll find the 268hp Falcon XR8 Sprint and GT variants of 1992, the 268hp Falcon GT of 1997, the 295hp Falcon TS50s from 1999-2001 and '01-'02 Falcon XR8s, and the 342ci 335hp TS50 and Pursuit variants of 2002.
After a wee bit of Googling those Falcons appear to be the product of "Tickford;' some sort of entity contracted by Ford-AU to build these hi-po versions (something I'm sure you know), so with that I don't know if we can call this "Ford."
Just about any yahoo can easily build with ~$2,000 worth of parts from just about any hot rod shop (Summit, Jegs, PAW, etc.) a small-block Ford of 350+hp; that's not hard. What's hard is getting good NVH, good driveability and good durability, amongst other things. As the market dictated more power and better NVH, the small-block Ford simply couldn't keep up.
1. You guys are dorks
2. You can't compare the Ford 302 to a new motor weight wise unless you are talking an all aluminum 302 which weighs about 100-120# less than an iron one.
3. All these #'s are semantics and internet penis showing... at the end of the day I would rather the LSx motor. Yea the Merc motor might be DOHC but who gives a fuck? LSx parts are dirt cheap + in abundance, you can get one hooked up to a manual Tremec or w/e gearbox for like $4K, their ECUs are already tapped into and ready for tuning and even in their stone-age technology, as efficient as they are they STILL respond better to mods than comparable OHC V8s.
I GUARANTEE even in their increased production #'s DOHC motors cost more to make. On top of that like someone said 4V motors have more valvetrain loss (though their #'s were off). W/all that VVT VVL bullshit OHV motors are much easier to maintain or rebuild if necessary. For a down dirty sports car I don't know why anyone would choose anything BUT an LSx motor. Why complicate things needlessly?
Quote from: r0tor on June 10, 2009, 10:55:58 AM
i will conceed to there being am azing combination of weather effects that leads to a 1.00 CF... in any event, it is still putting out more power then any 6.3L OHV engine while weighing the same -shrug-
So does that mean I get to "call ultimate :facepalm:" you being a "nimrod" ? :evildude: :lol:
So have we come to a conclusion yet? Because I can't tell the difference. I like Corvette motors. Especially in GTOs.
All the OHC boys seems to be forgetting one of the most important variables: cost.
Quote from: SVT32V on June 10, 2009, 12:44:02 PM
The Ford 5.0 fully dressed for smog regulations of the mid 1990s was over 500 lbs. You can't compare your carbed smogless aftermarket modified engine to a factory engine that has to pass smog and have a warranty. Apples and oranges.
I compare it in ready to run form, or to basic engine minus electronics. What it took to make it run
in my car. And I can certainly compare the length, height, and width of it in that form. the weights i use are based on what engine swappers have to work with for each engine, not the auxiliary stuff that's neede in their factory application. The 4.6 is still heavier, longer, wider, and taller. Even the basic engine, stripped of all it's crap, does not physically fit where teh 289/302/5.0 fits.
It still had cast iron block and heads. It's only concession to weight savings was aluminum intake manifold (similar to the high po one Ford had available for the small block during it's production run).
Considering I am currently comparing the SBF to the Lexus DOHC in the form that each need to be in to run
in my car now, and emissions controls in the newer engine are not a factor (in fact, I was looking into using the Australian Holley carb intake manifold setup for the Lexus engine in street rods and circle track racers down under), and the engine becomes even MORE comparable.
Simply put, the "newer" DOHC engine is physically larger, heavier, and more complex for the same power output.
Quote from: omicron on June 10, 2009, 08:31:13 AM
That is so painfully awesome it hurts my head just to think about it. I want it.
Yes, it is. I need to lie down now.
QuoteOf course there were wonderful examples of small block fords but we are talking about the ubiquitous 5.0 of the 90s that was in the picture.
Is there some size difference between the '90s 302, and the '60s 302 that I'm not aware of? We're discussing pushrod engines in general, and SBFs and SBCs in particular. Now you're trying to say that the flaws of a particular '90s version of the SBF is the entire reason to discount pushrods?
Quote
Yup, some get lucky but Ford could never warranty a 390 hp 5.0 like the '03 cobra.
Ford never tried to warranty one like mine, but mine lasted a long time in modded form, so it was apparenlty capable of considerably more than teh factory state of tune. Do not fall into the trap of thinking that the factory warrantied state of tune was it's ultimate reliable ability. I mean, I built a Fox mustang with a 466 cid 460 based engine that had over 700 lb ft of torque, over 500 hp, and was a reliable daily driver/track car for over a decade for it's new owner. And I didn't use exotic parts (most of the parts were out of the Ford catalog). What the factory decided was adequte for sale, and what the engines were capable of with only minor tweaks are often considerably different.
Quote
Yeah, good luck smog certifying it as a production smog passing car.
We're not talking about smog legal. We're talking about physical size. I could have made it smog legal with very little effort.
And again, since this was a general pushrods vs OHC, what Ford did is different than what GM did. GM was apparently able to make power reliably from a smog legal N/A engine, in about the same physical space, at the same weight. Similar tweaks to the Ford engine can generate good power, reliably, too.
Quote
The aluminum 3V weighs 420lbs fully dressed.
You said that already. Source? All the guys putting them into other cars (or trying to) are finding they are much heavier in actuality.
Quote
The 5.0 is much narrower than the 4.6, no argument there.
And we come back to the basic point: physical packaging for the same displacement is much more compact for the pushrod engine, as well as being simpler and lower cost for similar outputs.
Yes sporty, sure they cost more; so do disc brakes vs. drum, EFI vs. carb, independent suspension vs. rigid axle, unibody vs. BoF, etc., and OHC vs. push rod fits exactly within this list (i.e., costs more but is superior technology).
4V motors do not have more valve train loss; the valve springs on push rod valve trains are massive owing to all that mass (lifter + pushrod + rocker arm) that must be kept in check; at best it's a wash and I would not be surprised if the OHC valve train has less losses.
I'm simply amazed every time this "issue" comes up. There is no debate save for the issue raised about modding. Automakers do not build cars to be modded, they build them to perform and otherwise meet the needs of the market; and simply put, OHC owns push rod in this regard.
Quote from: TBR on June 10, 2009, 01:42:57 PM
All the OHC boys seems to be forgetting one of the most important variables: cost.
All the cam-in-block neanderthals seem to be forgetting
the most important variable:
V-TAK
Quote from: GoCougs on June 10, 2009, 01:58:26 PM
Yes sporty, sure they cost more; so do disc brakes vs. drum, EFI vs. carb, independent suspension vs. rigid axle, unibody vs. BoF, etc., and OHC vs. push rod fits exactly within this list (i.e., costs more but is superior technology).
Except with disc brakes vs. drums, EFI vs. carbs, etc, etc, there is a clear, significant difference in performance between the older technology and the newer one. That isn't the case with OHV and OHC, among engines of equal weight and dimensions, performance differences are negligible.
V-TEC is one of the modern marvels of engine building, and solves the most vexing problem that performance engine builders ahve had since teh beginning: a cam profile that is toquey and streetable isn't very suitable for high performance use, and a high performance cam profile, that revs good and makes power, tends to be peaky and lopey, and really poor for around town driveability.
Having two separate cam lobe profiles in one engine, that swith off just before the limitations of one profile become evident, is sheer genius. it's mroe effective in small displacement engines that really lose driveability when you cam them to make useable power, as larger engines already make enogh low end torque that a fairly good compromise can be made without sacrificing driveability.
But even then, those old school hotrodders that put "3/4 race cams" in their cars and lost streetability would have loved a system that effectively pulled out the stock cam as you got on the throttle and installed teh race cam, then swapped back to the stock cam when you got back off the throttle later....
Quote from: TBR on June 10, 2009, 02:02:46 PM
Except with disc brakes vs. drums, EFI vs. carbs, etc, etc, there is a clear, significant difference in performance between the older technology and the newer one. That isn't the case with OHV and OHC, among engines of equal weight and dimensions, performance differences are negligible.
Example:
BMW 4.0l V8 vs. Chevrolet LS3
The LS3 weighs less (by ~20 lbs from what I can see), has more horsepower, has significantly more torque, and is surely much cheaper to build.
Quote from: NACar on June 10, 2009, 01:59:12 PM
All the cam-in-block neanderthals seem to be forgetting the most important variable: V-TAK
http://www.youtube.com/watch?v=vAQDSNA9-B8
Quote from: TBR on June 10, 2009, 02:02:46 PM
Except with disc brakes vs. drums, EFI vs. carbs, etc, etc, there is a clear, significant difference in performance between the older technology and the newer one. That isn't the case with OHV and OHC, among engines of equal weight and dimensions, performance differences are negligible.
Unbelievable - you've just had 3+ pages of it - push rod I4 and 6 cylinder engines are virtually non-existent because they couldn't keep up as the market pushed NVH and power requirements ever higher, and for every push rod engine left there's a OHC variant that owns it.
Quote from: ChrisV on June 10, 2009, 02:04:15 PM
V-TEC is one of the modern marvels of engine building, and solves the most vexing problem that performance engine builders ahve had since teh beginning: a cam profile that is toquey and streetable isn't very suitable for high performance use, and a high performance cam profile, that revs good and makes power, tends to be peaky and lopey, and really poor for around town driveability.
Having two separate cam lobe profiles in one engine, that swith off just before the limitations of one profile become evident, is sheer genius. it's mroe effective in small displacement engines that really lose driveability when you cam them to make useable power, as larger engines already make enogh low end torque that a fairly good compromise can be made without sacrificing driveability.
But even then, those old school hotrodders that put "3/4 race cams" in their cars and lost streetability would have loved a system that effectively pulled out the stock cam as you got on the throttle and installed teh race cam, then swapped back to the stock cam when you got back off the throttle later....
And then there's VANOS :mrcool:
Quote from: GoCougs on June 10, 2009, 02:11:09 PM
Unbelievable - you've just had 3+ pages of it - push rod I4 and 6 cylinder engines are virtually non-existent because they couldn't keep up as the market pushed NVH and power requirements ever higher, and for every push rod engine left there's a OHC variant that owns it.
Find me the OHC engine that "owns" the LS3.
Quote from: TBR on June 10, 2009, 02:07:42 PM
Example:
BMW 4.0l V8 vs. Chevrolet LS3
The LS3 weighs less (by ~20 lbs from what I can see), has more horsepower, has significantly more torque, and is surely much cheaper to build.
the LS3 also has 50% more displacement to utilize. Compared to the Mercedes 6.2L its the same weight and produces less power and less torque. Cheapness to build boils down to mass production. If OHC engines were more expensive to build, every small econobox would not be using OHC engines
Quote from: TBR on June 10, 2009, 03:49:18 PM
Find me the OHC engine that "owns" the LS3.
Uh, they've already been listed; BMW 5.0L V10, M-B 6.2L V8, Porsche 3.8L F6 (and I'm staying well clear of the exotics...)...
Quote from: GoCougs on June 10, 2009, 04:37:49 PM
Uh, they've already been listed; BMW 5.0L V10, M-B 6.2L V8, Porsche 3.8L F6 (and I'm staying well clear of the exotics...)...
BMW V-10 isn't exotic now... OK
And yea the 500 HP from the BMW V10 is so much more powerful than that from the LS6...... :wtf: :hammerhead:
W/in the realm of SPORTS CARS, the LSx for all intents and purposes is just as good as any other V8 for putting down power, and IMO is a smarter design than a needlessly complex OHC motor. You're stuck in minor meaningless details... when it comes to high performance or truck V8s there is NO REASON to go OHC over OHV.
Quote from: r0tor on June 10, 2009, 04:17:06 PM
the LS3 also has 50% more displacement to utilize. Compared to the Mercedes 6.2L its the same weight and produces less power and less torque. Cheapness to build boils down to mass production. If OHC engines were more expensive to build, every small econobox would not be using OHC engines
One issue push rod fanboys forget is that their are
two basic production cost components to a manufactured item: direct material (DM) and direct labor (DL). It is obvious the OHC engine has more DM in that there is simply more material. However, DL is very much in question. Of note, the valve train on a push rod engine cannot be completed (installation of push rods and rockers, and their adjustment) until the heads are on the engine. With an OHC engine, the valve train can be fully assembled independent of the engine, save for the timing chain/belt. When one is building a few engines the difference is small, however when one is building 200,000 - 750,000 such engines a year, the manufacturing efficiency (i.e., parallel tasking) is substantial.
As you, I remain unconvinced that push rod engines are materially cheaper to manufacture. Ford, Nissan and Toyota manage with OHC V8s in their trucks for not materially more cost than GM or Dodge, and the latter certainly don't have the immense economy of scale of GM or Dodge (as in, they're not building hundreds of thousands of such engines). Further, GM only offers their 6.2L in only the top end crew cab Silverado, and even more expensive vehicles (Escalade, Denali, Corvette, etc.), whereas the Toyota 5.7L is available in a short-box, regular cab Tundra for ~$25k.
Quote from: r0tor on June 10, 2009, 04:17:06 PM
the LS3 also has 50% more displacement to utilize. Compared to the Mercedes 6.2L its the same weight and produces less power and less torque. Cheapness to build boils down to mass production. If OHC engines were more expensive to build, every small econobox would not be using OHC engines
WHO GIVES 2 SHITS ABOUT DISPLACEMENT?!
Given that the two engines are approximately the same size and weight, all that matters is power delivery and efficiency. All signs point to the pushrod being at least equal, if not better, in both categories.
Last I checked, we didn't get taxed by displacement in the US, so shut it about displacement already. That doesn't matter at all.
And cheapness
DOES NOT boil down to mass production. God, we just watched 2 companies prove this isn't true.
Comparing OHC and OHV in 4 cylinders is pointless because no one makes pushrod 4 cylinders. Apples to fuckin' oranges man...
Don't make me ashamed to like rotaries too man. :evildude:
Quote from: GoCougs on June 10, 2009, 04:51:44 PM
One issue push rod fanboys forget is that their are two basic production cost components to a manufactured item: direct material (DM) and direct labor (DL). It is obvious the OHC engine has more DM in that there is simply more material. However, DL is very much in question. Of note, the valve train on a push rod engine cannot be completed (installation of push rods and rockers, and their adjustment) until the heads are on the engine. With an OHC engine, the valve train can be fully assembled independent of the engine, save for the timing chain/belt. When one is building a few engines the difference is small, however when one is building 200,000 - 750,000 such engines a year, the manufacturing efficiency (i.e., parallel tasking) is substantial.
As you, I remain unconvinced that push rod engines are materially cheaper to manufacture. Ford, Nissan and Toyota manage with OHC V8s in their trucks for not materially more cost than GM or Dodge, and the latter certainly don't have the immense economy of scale of GM or Dodge (as in, they're not building hundreds of thousands of such engines). Further, GM only offers their 6.2L in only the top end crew cab Silverado, and even more expensive vehicles (Escalade, Denali, Corvette, etc.), whereas the Toyota 5.7L is available in a short-box, regular cab Tundra for ~$25k.
Parallel manufacturing is not a necessity in efficient manufacturing. FACT. Direct material is much more important.
not including displacement is then like bragging a 6L V8 makes more power then a 2.3L normally aspirated 4 banger... the "no shit" argument needs to apply
Quote from: sportyaccordy on June 10, 2009, 04:48:25 PM
BMW V-10 isn't exotic now... OK
And yea the 500 HP from the BMW V10 is so much more powerful than that from the LS6...... :wtf: :hammerhead:
W/in the realm of SPORTS CARS, the LSx for all intents and purposes is just as good as any other V8 for putting down power, and IMO is a smarter design than a needlessly complex OHC motor. You're stuck in minor meaningless details... when it comes to high performance or truck V8s there is NO REASON to go OHC over OHV.
How exactly is the BMW V10 exotic?
Dry sump like the LS7? No.
CNC-machined ports like the LS7? No.
Titanium and sodium-filled valves like the LS7? No.
Titanium con-rods like the LS7? No.
The LSx is okay for making cheap power, but again, for each iteration there is an OHC engine that is superior.
Quote from: r0tor on June 10, 2009, 05:30:53 PM
not including displacement is then like bragging a 6L V8 makes more power then a 2.3L normally aspirated 4 banger... the "no shit" argument needs to apply
If the 6 liter V8 got better gas mileage too, I wouldn't give a fuck then still.
What don't you get about that? There's only two things this argument boils down to if weight and size are approximately equal: power (how much, and how it's delivered), and efficiency.
You might as well bitch about some other completely useless fact. Like the Corvette's engine uses thicker plastic on the intake, so therefore it's not a fair comparison.
Quote from: GoCougs on June 10, 2009, 05:31:14 PM
How exactly is the BMW V10 exotic?
Dry sump like the LS7? No.
CNC-machined ports like the LS7? No.
Titanium and sodium-filled valves like the LS7? No.
Titanium con-rods like the LS7? No.
The LSx is okay for making cheap power, but again, for each iteration there is an OHC engine that is superior.
:facepalm: Have you read anything about BMW's V10? It's quite possibly one of the most complex engines being made today.
its because when you bring up a power output of a 4l V8 that makes more then a 5.7L V8, the fanboi's jump in about torque (which is a function of displacement). So the only alternative it using equal displacement engines and then the OHC engine will always have more hp and a broader torque curve.
Quote from: MrH on June 10, 2009, 05:29:34 PM
Parallel manufacturing is not a necessity in efficient manufacturing. FACT. Direct material is much more important.
Uh,
The Goal (http://en.wikipedia.org/wiki/The_Goal_(novel)). As told to Spicoli - Learn it. Know it. Live it.
If in these processes DL was so unimportant, how can Toyota and Nissan price vehicles with a DOHC VVT all-aluminum V8 at the same price as the push rod competition?
(Do not underestimate the benefit of decreasing seemingly small DL on such a high-volume, complex product. I've lived this.)
Quote from: r0tor on June 10, 2009, 05:30:53 PM
not including displacement is then like bragging a 6L V8 makes more power then a 2.3L normally aspirated 4 banger... the "no shit" argument needs to apply
I'm not so sure you should be in an argument about displacement, Power or fuel economy given what you drive.
hell, i've defended the LS2 on many rotary boards because it gets the job done. Its a good engine with good output thanks to its displacement.
The engineer in me can't go along with its actually better in any way over a OHC engine because its not thanks to the OHC having a higher revving potential due to directly enacting valves and not having the pushrods to move around and also better flow from a the variable valve timing aspects and not having to snake the ports around pushrods. Its proven on here the modern large displacement OHC engines DO NOT weigh more. The do not need to cost more. I'll still put money down on any pushrod V8 automobile also having an engine bay big enough to accept a Merc or BMW OHC engine too.
Quote from: MrH on June 10, 2009, 05:33:36 PM
:facepalm: Have you read anything about BMW's V10? It's quite possibly one of the most complex engines being made today.
Again, How exactly is the BMW V10 exotic?
Quote from: r0tor on June 10, 2009, 05:30:53 PM
not including displacement is then like bragging a 6L V8 makes more power then a 2.3L normally aspirated 4 banger... the "no shit" argument needs to apply
The Corvette with an LS3 produces 266 more horsepower then my 2.0L four banger in my SVT Focus, and the Vette gets the same highway mileage.
Quote from: HEMI666 on June 10, 2009, 05:52:26 PM
The Corvette with an LS3 produces 266 more horsepower then my 2.0L four banger in my SVT Focus, and the Vette gets the same highway mileage.
and in normal sedans and trucks that its found in, it does not really shine above the competition
Quote from: HEMI666 on June 10, 2009, 05:52:26 PM
The Corvette with an LS3 produces 266 more horsepower then my 2.0L four banger in my SVT Focus, and the Vette gets the same highway mileage.
Gearing and aerodynamics. Most any economy car will match, or outright walk, a Corvette in a 45-75 mph top gear roll-on.
Quote from: HEMI666 on June 10, 2009, 05:52:26 PM
The Corvette with an LS3 produces 266 more horsepower then my 2.0L four banger in my SVT Focus, and the Vette gets the same highway mileage.
And the bigger, heavier, and just-as-fast 911-S gets even better mileage (19/26 vs. 16/26) without the benefit of neither a 0.5:1 top gear nor 1-4 skip shift...
Quote from: GoCougs on June 10, 2009, 06:02:28 PM
And the bigger, heavier, and just-as-fast 911-S gets even better mileage (19/26 vs. 16/26)...
Not anymore, Porsche has recently revised their MPG ratings for ther 997.2 cars.
The 997.2 Carrera S doesn't get 19/26 anymore.
Not even the base Carrera gets 19/26.
The base Carrera gets 18/26 while the Carrera S gets 17/25.
http://www.porsche.com/usa/models/911/911-carrera/featuresandspecs/?gtabindex=7
Plus manual Carrera S curb weight: 3131 lbs.
http://www.porsche.com/usa/models/911/911-carrera-s/featuresandspecs/?gtabindex=5
Compared to manual Corvette base curb weight: 3217 lbs.
http://www.chevrolet.com/vehicles/2009/corvettecoupe/features.do
The PDK Carrera S base does weigh all of 2 pounds more than the Corvette manual.
Quote from: GoCougs on June 10, 2009, 05:31:14 PM
How exactly is the BMW V10 exotic?
Dry sump like the LS7? No.
CNC-machined ports like the LS7? No.
Titanium and sodium-filled valves like the LS7? No.
Titanium con-rods like the LS7? No.
The LSx is okay for making cheap power, but again, for each iteration there is an OHC engine that is superior.
Cougs, bossman
Does the LS7 have
- 4 camshafts?
- 4V/cyl?
- Cam angle phasing?
- Individual throttle bodies?
- An engine management system that analyzes combustion chamber content to control knock through the spark plugs?Can you imagine how much of a nightmare a basic tune up on the M5/M6 will be? I am sure tune-up time mileage cars will take a huge depreciation hit.
All that to make 500HP from 5L. Progress my ass. BMW achieved that kind of efficiency nearly 20 years ago w/basically the same technology- only now I am sure it will be a nightmare to maintain. Forget about seeing this motor in any kind of motorsport capacity... I'd say the same for the M3's V8... these motors are exotic, no doubt about it.
As far as the stuff you listed for the LS7, beyond the dry sump pump all the other stuff can be found in relatively run of the mill cars at least 8 years old (Q45, NSX, ITR). If we are going to call the Integra Type R's 1.8L 4 banger "exotic" then yes the LS7 is exotic too.
Quote from: r0tor on June 10, 2009, 05:36:50 PM
its because when you bring up a power output of a 4l V8 that makes more then a 5.7L V8, the fanboi's jump in about torque (which is a function of displacement). So the only alternative it using equal displacement engines and then the OHC engine will always have more hp and a broader torque curve.
Dude you are totally missing the point. Yes displacement is one factor in an engine. But what difference does displacement make when you have a motor like the LS7 that is significantly smaller in size, weight, complexity & cost making the same exact power as the million dollar V10 in the M5/6? You don't have to be an engineer to see which motor makes more sense.
By the same token though obviously OHV isn't the be all end all... things have to be looked at at an application to application basis. Beyond the badge and tech snobbery ultimately there is something to be said about the LSx motor.
Quote from: 565 on June 10, 2009, 06:35:40 PM
Not anymore, Porsche has recently revised their MPG ratings for ther 997.2 cars.
The 997.2 Carrera S doesn't get 19/26 anymore.
Not even the base Carrera gets 19/26.
The base Carrera gets 18/26 while the Carrera S gets 17/25.
http://www.porsche.com/usa/models/911/911-carrera/featuresandspecs/?gtabindex=7
Plus manual Carrera S curb weight: 3131 lbs.
http://www.porsche.com/usa/models/911/911-carrera-s/featuresandspecs/?gtabindex=5
Compared to manual Corvette base curb weight: 3217 lbs.
http://www.chevrolet.com/vehicles/2009/corvettecoupe/features.do
The PDK Carrera S base does weigh all of 2 pounds more than the Corvette manual.
I was comparing the Tiptronic version of the car, not the manual. And the "revised" 17/25 is still at least equivalent to 16/26, and still without benefit of a neither 0.50:1 top gear nor a 1-4 skip shift...
To drive the point home further, the AWD Turbo (16/23) has at least equivalent MPG to the Z06 (15/24), even with AWD, no 0.50:1 top gear, and ~300 lb additional pounds.
THE BEST ENGINE IS ONE THAT GOES VROOM THE BESTEST.
Quote from: Minpin on June 10, 2009, 07:25:43 PM
THE BEST ENGINE IS ONE THAT GOES VROOM THE BESTEST.
SWIFT.
Quote from: sportyaccordy on June 10, 2009, 07:30:53 PM
U should do a Hayabusa swap
But it only has 4000 miles on the rebuild! What a waste! :lockedup:
Quote from: GoCougs on June 10, 2009, 07:24:52 PM
I was comparing the Tiptronic version of the car, not the manual. And the "revised" 17/25 is still at least equivalent to 16/26, and still without benefit of a neither 0.50:1 top gear nor a 1-4 skip shift...
To drive the point home further, the AWD Turbo (16/23) has at least equivalent MPG to the Z06 (15/24), even with AWD, no 0.50:1 top gear, and ~300 lb additional pounds.
So you were comparing the weight of the PDK Carrera S to the weight of the manual C6.... why...
Anyway you answered your own question with that second point, because the 911 Turbo is a Turbo.
Lets compare NA to NA shall we.
Look at this comparo. The GT3 is only 60 pounds heavier than the Z06. It's got half the displacement. It's got 100 less horsepower. It's got worse performance in a straight line (the Z06 is a good 4mph faster through the 1/4 mile, and quicker too despite the GT3's rear engined launch).
Still in a direct comparison of fuel mileage, what is the real world result?
Z06: 16mpg
GT3: 14mpg
http://www.caranddriver.com/reviews/comparison_test/coupes/2007_chevrolet_corvette_z06_vs_2007_lotus_exige_s_2007_porsche_911_gt3_comparison_test
So basically for two cars of similar weight. The Z06 is faster and gets better fuel mileage. So there is this magical OHC superiority that promises more performance and efficiency?
Quote from: sportyaccordy on June 10, 2009, 06:57:30 PM
Cougs, bossman
Does the LS7 have
- 4 camshafts?
- 4V/cyl?
- Cam angle phasing?
- Individual throttle bodies?
- An engine management system that analyzes combustion chamber content to control knock through the spark plugs?
So in other words, no more exotic than the VANOS-equipped 3.0L I6 found in a ~$34k 328i and barely beyond that of a Civic...
Quote
Can you imagine how much of a nightmare a basic tune up on the M5/M6 will be? I am sure tune-up time mileage cars will take a huge depreciation hit.
All that to make 500HP from 5L. Progress my ass. BMW achieved that kind of efficiency nearly 20 years ago w/basically the same technology- only now I am sure it will be a nightmare to maintain. Forget about seeing this motor in any kind of motorsport capacity... I'd say the same for the M3's V8... these motors are exotic, no doubt about it.
As far as the stuff you listed for the LS7, beyond the dry sump pump all the other stuff can be found in relatively run of the mill cars at least 8 years old (Q45, NSX, ITR). If we are going to call the Integra Type R's 1.8L 4 banger "exotic" then yes the LS7 is exotic too.
Dude you are totally missing the point. Yes displacement is one factor in an engine. But what difference does displacement make when you have a motor like the LS7 that is significantly smaller in size, weight, complexity & cost making the same exact power as the million dollar V10 in the M5/6? You don't have to be an engineer to see which motor makes more sense.
By the same token though obviously OHV isn't the be all end all... things have to be looked at at an application to application basis. Beyond the badge and tech snobbery ultimately there is something to be said about the LSx motor.
None of this makes sense.
Oh and more direct 911 to Corvette comparisons with observed MPG. As no direct LS3 vs 997.2 911 comparo has been made, lets go to the last time these cars went head to head.
http://www.caranddriver.com/reviews/comparison_test/coupes/2005_chevrolet_corvette_z51_vs_porsche_911_carrera_comparison_test
C6: 114mph trap speed.
911: 109mph trap speed
a 5 mph difference in trap speed, aka a sizable power gap.
Still the observed MPG?
C6: 18mpg
911: 17mpg
What happened to all that OHC magic?
Dude, it got called on it. The Porsche 911 in its myriad forms has equivalent mileage and performance and is the bigger car, sometimes heavier, and even sometimes with AWD, all without benefit of 1-4 skip shift and/or 0.50:1 top gear, depending on model. As to the GT3? Kindly check this month's C&D (p. 116) for the new GT3 with its revised 3.8L. Also remember a F6 of less than 4.0L is going to be pretty small. Porsche objectively builds the superior power plant IMO.
Quote from: GoCougs on June 10, 2009, 07:57:44 PM
Dude, it got called on it. The Porsche 911 in its myriad forms has equivalent mileage and performance and is the bigger car, sometimes heavier, and even sometimes with AWD, all without benefit of 1-4 skip shift and/or 0.50:1 top gear, depending on model. As to the GT3? Kindly check this month's C&D (p. 116) for the new GT3 with its revised 3.8L. There's not much more to say - Porsche builds a superior power plant.
Do you really have to use the word, "myriad", in every single one of your posts?
Quote from: GoCougs on June 10, 2009, 07:57:44 PM
Dude, it got called on it. The Porsche 911 in its myriad forms has equivalent mileage and performance and is the bigger car, sometimes heavier, and even sometimes with AWD, all without benefit of 1-4 skip shift and/or 0.50:1 top gear, depending on model. As to the GT3? Kindly check this month's C&D (p. 116) for the new GT3 with its revised 3.8L. There's not much more to say - Porsche builds a superior power plant.
Does this new GT3 get better gas mileage than a Z06 while being faster? C&D's estimates don't seem to suggest it.
PERFORMANCE (C/D EST)
Zero to 60 mph: 3.7 sec
Standing ?-mile: 11.8 sec @ 120 mph
Top speed (drag limited): 193 mph
FUEL ECONOMY (MFR?S EST):
EPA city/highway driving: 15/22 mpg
Anyway if I was to go over to the dark side of FI DOHC...
(http://www.nissan-club.hr/home/images/stories/gtr-vr38-500.jpg)
>>>
(http://www.themotorreport.com.au/wp-content/uploads/2008/07/por_911dfi_engine.jpg)
Any day of the week.
Yes I did just bring *that* car into this debate.
Quote from: 565 on June 10, 2009, 08:02:38 PM
Does this new GT3 get better gas mileage than a Z06 while being faster? C&D's estimates don't seem to suggest it.
PERFORMANCE (C/D EST)
Zero to 60 mph: 3.7 sec
Standing ?-mile: 11.8 sec @ 120 mph
Top speed (drag limited): 193 mph
FUEL ECONOMY (MFR?S EST):
EPA city/highway driving: 15/22 mpg
Looking at that body work it's obvious down force is a major theme (i.e., acceleration sapping) as it has an extreme bent toward track use.
Further, you seem to be neglecting that it's an engine both only 54-62% the displacement and smaller than the LSx.
It's the better power plant.
WHICH ONE GOES VROOM THE BESTEST?????
http://www.youtube.com/watch?v=tbGuKKYtqtI&feature=related
or
http://www.youtube.com/watch?v=DG65mcICyuY&feature=related
Quote from: GoCougs on June 10, 2009, 07:43:45 PM
So in other words, no more exotic than the VANOS-equipped 3.0L I6 found in a ~$34k 328i and barely beyond that of a Civic...
None of this makes sense.
Coward...
Quote from: GoCougs on June 10, 2009, 08:08:27 PM
Looking at that body work it's obvious down force is a major theme (i.e., acceleration sapping) as it has an extreme bent toward track use.
Further, you seem to be neglecting that it's an engine both only 54-62% the displacement and smaller than the LSx.
It's the better power plant.
So we're back to HP/L again?
So what's the engine weight on the 3.8L? Porsche says it weighs the same as the old 3.6, but they never did say how much that weighed either.
Quote from: MX793 on June 10, 2009, 06:01:06 PM
Gearing and aerodynamics. Most any economy car will match, or outright walk, a Corvette in a 45-75 mph top gear roll-on.
Really?
I've got to find a Corvette to try this out.
Quote from: Raza on June 10, 2009, 10:18:47 PM
Really?
I've got to find a Corvette to try this out.
This actually doesn't prove much. Any real economy car would crush a C6 vette in a top gear roll 45-75 if the econo box is an automatic in the right gear vs the Corvette in top gear, but then it's not really a "top gear" roll test. Plus even with manual transmissions, alot of economy cars will get decent 30-70 times because the gearing is much shorter, but you could claim a similar victory over other high performance cars that are optimally geared but geared to hit really high speeds.
I mean here is the 30-50 and 50-70 passing top gear tests for all 3 corvettes.
http://www.caranddriver.com/content/download/125792/1704430/version/1/file/CD12CORVETTES_powertrain.pdf
The Z51 doesn't do that bad due its better gearing.
The Z06 does the worst, and the ZR1 crushes this test.
Compare this to some other high performance cars that do and don't use a economy gear.
http://www.caranddriver.com/content/download/110301/1496400/version/1/file/USA+Comparo+-+Powertrain.pdf
Here the GT-R and 911 GT2 don't use an economy gear (their top speeds are redline limited as indicated in the PDF), and indeed do better than the Z06 and Viper. However you can see the Z51 from that other test actually outpaces the GT-R and GT2 from 30-50, due to probably the lack of turbo lag. Overall 30-70 times are comparable between the Z51 and the GT-R/GT2. The Z06 does worse because of it's taller 6th, and the ZR1 will still crush them all.
Z51 combined 30-70 time: 17.2
GT-R combined 30-70 time: 16
GT2 combined 30-70 time: 17.4
Z06 combined 30-70 time: 21.9
ZR1 combined 30-70 time: 11.3
Anyway the point is the Z51 C6's 30-70 passing times are on par with other performance cars such as the GT2 and GT-R, which have pretty much perfectly placed top gears. The Z06 is a bit behind, but by no means impossibly slow. The ZR1 is a beast. Yes the Corvette does have a very tall top gear. Yet as cars get faster and faster, they need taller and taller top gears to allow them to hit those high top speeds, and thus top gear passing suffers even in cars with perfect gearing. Both the GT-R and GT2 hit their top speeds of around 200mph at the top of their highest gear and they both run about comparable 30-70 times to the Z51.
If you could walk a Z51 in your car from 30-70, you could probably go walk a GT-R or GT2 as well.
Quote from: GoCougs on June 10, 2009, 02:11:09 PM
for every push rod engine left there's a OHC variant that owns it.
Saleen S7 TT-C: 1000hp, 7.0L, 8 cyl, 2 turbos, 2v/cyl, OHV.
Bugatti Veyron 16.4: 1001hp, 8.0L, 16 cyl, 4 turbos, 4v/cyl, DOHC.
:huh:
Dude, you're only proving their point. Don't you see the bugatti owns that saleen like no other, look at the power difference, spanks the crap out of the saleen...
I do like the Ultimate Aero's power out of their turbo 6.4L V8, 1287hp/1112tq :mask: Per their site they say the engine weighs 422lbs... that actually sounds hard to believe must be without the turbos and stuff just the engine dressed up. But it's not DOHC so it's junk and a DOHC one would be more powerful, same size, weigh less. :rolleyes:
Quote from: sportyaccordy on June 10, 2009, 06:57:30 PM
But what difference does displacement make when you have a motor like the LS7 that is significantly smaller in size, weight, complexity & cost making
ok...
PROVE the LS7 weighs significantly less then most of its competitors DOHC V8's
PROVE that its less "complex"
PROVE that its cheaper to make
the reality is all 3 of those arguements utterly fail
I gots a cargo cover in mines. So there.
It's fun watching smarter people than myself hash out all these details so I can go back and read it later and make up my own mind. ;)
Busy, busy.
The point was that the Porsche 3.8L F6 is going to smaller and weigh less than a 6.2L or 7.0L push rod V8.
Cherry picking exotic or custom motors ignores significant attributes in play in the retail market such as NVH and efficiency.
As to ultimate hp I think one would be disappointed in a "never meet your heroes" kind of way after visiting the local drag strip.
Someone stated that there are no 4-valve push rod motors; not true, some diesels are - the Duramax is for example.
Quote from: GoCougs on June 11, 2009, 08:27:51 AM
Busy, busy.
The point was that the Porsche 3.8L F6 is going to smaller and weigh less than a 6.2L or 7.0L push rod V8.
(http://www.renegadehybrids.com/911/Pictures/LS-1Pic01.jpg)
Rod Simpson found that installing an aluminum head, cast iron chevy small block in the back of a Porsche 930 didn't change the weight or weight distribution one bit.
The LS series engines weigh less than the cast iron SBC, and the Porsche 3.8 weighs MORE than the turbo 3.3 in the 930.
http://www.renegadehybrids.com/PressReleases/PR09.html
http://www.renegadehybrids.com/indexx.html
"Reduced weight of the LS Series is also a HUGE advantage over the "big" 911 motors. Weighing less than a completely dressed 3.0L NA motor, the LS Series has turbo performance with much less than turbo six weight. With less weight in the rear and more power under your right foot, you can see why a converted 911 is so much fun to drive."
Cougs, you fail again. Once again, people that actually WORK on the cars, do the conversions, and weigh them know more than the armchair engineers like yourself.
Just stop. Or start... working on cars instead of making up BS.
Quote from: GoCougs on June 10, 2009, 07:24:52 PM
I was comparing the Tiptronic version of the car, not the manual. And the "revised" 17/25 is still at least equivalent to 16/26, and still without benefit of a neither 0.50:1 top gear nor a 1-4 skip shift...
To drive the point home further, the AWD Turbo (16/23) has at least equivalent MPG to the Z06 (15/24), even with AWD, no 0.50:1 top gear, and ~300 lb additional pounds.
1-4 skip shift doesn't affect highway mileage.
Quote from: MX793 on June 10, 2009, 06:01:06 PM
Gearing and aerodynamics. Most any economy car will match, or outright walk, a Corvette in a 45-75 mph top gear roll-on.
I doubt my car would. It doesn't like 6th gear much below 55 mph.
Quote from: ChrisV on June 11, 2009, 08:36:37 AM
(http://www.renegadehybrids.com/911/Pictures/LS-1Pic01.jpg)
Rod Simpson found that installing an aluminum head, cast iron chevy small block in the back of a Porsche 930 didn't change the weight or weight distribution one bit.
The LS series engines weigh less than the cast iron SBC, and the Porsche 3.8 weighs MORE than the turbo 3.3 in the 930.
http://www.renegadehybrids.com/PressReleases/PR09.html
http://www.renegadehybrids.com/indexx.html
"Reduced weight of the LS Series is also a HUGE advantage over the "big" 911 motors. Weighing less than a completely dressed 3.0L NA motor, the LS Series has turbo performance with much less than turbo six weight. With less weight in the rear and more power under your right foot, you can see why a converted 911 is so much fun to drive."
Cougs, you fail again. Once again, people that actually WORK on the cars, do the conversions, and weigh them know more than the armchair engineers like yourself.
Just stop. Or start... working on cars instead of making up BS.
Actually, I think your continued attacks and otherwise taking offense shows IMO that you don't quite have the knowledge that you think you do, or are in the least self-conscious about the knowledge you do have.
First, the conversion is interesting but "Rod" is displacing motor technology that is decades old;
Second, comparing weight and its distribution of the entire car itself not a proper substitute for the engines themselves;
Third, color me unconvinced that a 12 valve 3.0L F6 is bigger and heavier than an engine twice the displacement.
Fourth, I have worked on cars, and WRT to this very thread, have indeed rebuilt engines (small bock Chevy/Mopar) and otherwise tinkered a fair amount with tuning/optimizing them (carbs, intakes, cams/lifters/rockers, heads, exhaust).
Fifth, the principal mistake you and others are making is equating design and engineering; they aren't the same, and precisely whey you'll never, ever see a push rod engine from Porsche or any other of the world's automakers save for two in bankruptcy (who have save for a lone V8 each have dumped push rod valve trains for new engine designs).
Quote from: r0tor on June 11, 2009, 05:42:32 AM
ok...
PROVE the LS7 weighs significantly less then most of its competitors DOHC V8's
PROVE that its less "complex"
PROVE that its cheaper to make
the reality is all 3 of those arguements utterly fail
LS1: 420#
LS7: 458#
MB 6.2: 438#
BMW V10: 528#
BMW V8: 445#
Weight argument is out
Saying an LSx is anywhere near as complex as say the BMW V8/V10 is just foolish. The ionic knock sensor system alone puts it in a whole different category. And yea while the LS7 has little extras like titanium con rods or w/e ultimately the DOHC motors just have more going on. You don't think there's any cost associated with the additional valves, springs, throttle bodies, cam phasing hardware/software, etc.? Beyond the scales of economy & the individual company financial issues please let me know how an LS7 could cost MORE to make than the M3's V8.
Quote from: 2o6 on June 09, 2009, 01:06:08 PM
Really, if it's producing loads of power, or good fuel economy I don't see the point of this debate.
Quote from: TBR on June 09, 2009, 01:09:27 PM
I agree. Looking at the results of the LS series of engines, what's the point of this argument? Lots of power in a light package with respectable fuel economy, what's wrong with that?
..........
Quote from: GoCougs on June 10, 2009, 05:37:30 PM
Uh, The Goal (http://en.wikipedia.org/wiki/The_Goal_(novel)). As told to Spicoli - Learn it. Know it. Live it.
If in these processes DL was so unimportant, how can Toyota and Nissan price vehicles with a DOHC VVT all-aluminum V8 at the same price as the push rod competition?
(Do not underestimate the benefit of decreasing seemingly small DL on such a high-volume, complex product. I've lived this.)
You're going to cite a fictional novel for your manufacturing knowledge?
You gotta be kidding me man. Parallel processing helps a lot when it comes to change over times and the such, but it is not a necessity. If anything, not being to able complete the work on the valve train until the heads are on the engine will simply increase the amount of product being worked at once.
If you seriously think that's the only reason why Toyota is so efficient, you don't have a fucking clue what you're talking about.
http://www.amazon.com/Lean-Manufacturing-Plant-Floor-Guide/dp/0872635252 Try reading that instead.
God, this whole argument is painful to read. HP/liter means absolutely nothing. You should just pick any arbitrary stat about an engine and quote that for being the reason it's better.
Well, I think someone said in the original thread that this spun off of that there is no such thing as "best". There is nearly always some advantage to be found in different packaging and design, with corresponding compromises in other areas. For example, the physical size of a OHC engine versus OHV, the cheapness of drum brakes despite better performance from disks, etc. etc.
Quote from: R-inge on June 11, 2009, 10:16:38 AM
Well, I think someone said in the original thread that this spun off of that there is no such thing as "best". There is nearly always some advantage to be found in different packaging and design, with corresponding compromises in other areas. For example, the physical size of a OHC engine versus OHV, the cheapness of drum brakes despite better performance from disks, etc. etc.
I wish that was the case, but people on this forum seem hell bent to declare engines better than others, based merely on hp/liter arguments.
Quote from: GoCougs on June 11, 2009, 09:42:03 AM
Actually, I think your continued attacks and otherwise taking offense shows IMO that you don't quite have the knowledge that you think you do, or are in the least self-conscious about the knowledge you do have.
Or maybe it's because I think you're a total moron and don't like you at all.
The fact that you make this statement:
"The point was that the Porsche 3.8L F6 is going to smaller and weigh less than a 6.2L or 7.0L push rod V8."
And then come up with other BS to discount anything said against it, shows you don't know anywhere near what YOU think you do.
The fact is that the water cooled flat 6 is heavier than the air cooled flat 6, and the LSx engine is lighter than the air cooled flat 6. Thus the LSx is lighter than the water cooled 3.8. People who do the conversions all the time know this, and prove it in every car they build. You can't accept that because your limited practical knowledge gets in your way.
"Third, color me unconvinced that a 12 valve 3.0L F6 is bigger and heavier than an engine twice the displacement."
Never let facts get in your way, Cougs.
"Fourth, I have worked on cars, and WRT to this very thread, have indeed rebuilt engines (small bock Chevy/Mopar) and otherwise tinkered a fair amount with tuning/optimizing them (carbs, intakes, cams/lifters/rockers, heads, exhaust)."
That has nothing to do with taking them out, weighing them, and making them fit in places they were not originally in. And it has zero bearing on working with people and companies that do precisely that on a regular basis.
Quote from: MrH on June 11, 2009, 10:33:13 AM
I wish that was the case, but people on this forum seem hell bent to declare engines better than others, based merely on hp/liter arguments.
on EVERY forum.
If hp/liter meant the best engine, then a COX .049 engine would be the best engine to power your car, due to it's nearly 500hp/liter rating.
Quote from: MrH on June 11, 2009, 10:00:27 AM
You're going to cite a fictional novel for your manufacturing knowledge?
You gotta be kidding me man. Parallel processing helps a lot when it comes to change over times and the such, but it is not a necessity. If anything, not being to able complete the work on the valve train until the heads are on the engine will simply increase the amount of product being worked at once.
If you seriously think that's the only reason why Toyota is so efficient, you don't have a fucking clue what you're talking about.
http://www.amazon.com/Lean-Manufacturing-Plant-Floor-Guide/dp/0872635252 Try reading that instead.
Here's some advice:
The Goal is required reading at many a large, high-volume manufacturer (such as my former well-known mulit-national employer, plus GE, Intel and many others), the MBA program I attended (and many others), and in the summer class (http://ocw.mit.edu/OcwWeb/Sloan-School-of-Management/15-760AOperations-ManagementSpring2002/Syllabus/) I took at MIT.
Here's more advice: Beware the sin of hubris. I'm a practicing, licensed engineer with an MBA in tech and mfg management, with 13 years' experience in factory design and management, and you're an undergrad college student. This simply means I'm much smarter and infinitely more practiced than you in these things.
So with that unpleasantness out of the way, I was not commenting on the success whole of the world's largest and most successful manufacturer. I essentially merely commented as to the advantages of sub assemblies in manufacturing, something that even the greenest operations management student should have picked up on.
As to your critique; "complete the work on the valve train?" I think you're missing some basic technical aspects of the two valve train configurations.
Quote from: GoCougs on June 11, 2009, 10:39:00 AM
Here's some advice: The Goal is required reading at many a large, high-volume manufacturer (such as my former well-known mulit-national employer, plus GE, Intel and many others), the MBA program I attended (and many others), and in the summer class (http://ocw.mit.edu/OcwWeb/Sloan-School-of-Management/15-760AOperations-ManagementSpring2002/Syllabus/) I took at MIT.
Here's more advice: Beware the sin of hubris. I'm a practicing, licensed engineer with an MBA in tech and mfg management, with 13 years' experience in factory design and management, and you're an undergrad college student. This simply means I'm much smarter and infinitely more practiced than you in these things.
So with that unpleasantness out of the way, I was not commenting on the success whole of the world's largest and most successful manufacturer. I essentially merely commented as to the advantages of sub assemblies in manufacturing, something that even the greenest operations management student should have picked up on.
As to your critique; "complete the work on the valve train?" I think you're missing some basic technical aspects of the two valve train configurations.
So because you're more experienced + educated ppl can't tell you you're wrong? Whose indulging in the sin of hubris here?
Quote from: ChrisV on June 11, 2009, 10:35:36 AM
Or maybe it's because I think you're a total moron and don't like you at all.
The fact that you make this statement:
"The point was that the Porsche 3.8L F6 is going to smaller and weigh less than a 6.2L or 7.0L push rod V8."
And then come up with other BS to discount anything said against it, shows you don't know anywhere near what YOU think you do.
The fact is that the water cooled flat 6 is heavier than the air cooled flat 6, and the LSx engine is lighter than the air cooled flat 6. Thus the LSx is lighter than the water cooled 3.8. People who do the conversions all the time know this, and prove it in every car they build. You can't accept that because your limited practical knowledge gets in your way.
"Third, color me unconvinced that a 12 valve 3.0L F6 is bigger and heavier than an engine twice the displacement."
Never let facts get in your way, Cougs.
"Fourth, I have worked on cars, and WRT to this very thread, have indeed rebuilt engines (small bock Chevy/Mopar) and otherwise tinkered a fair amount with tuning/optimizing them (carbs, intakes, cams/lifters/rockers, heads, exhaust)."
That has nothing to do with taking them out, weighing them, and making them fit in places they were not originally in. And it has zero bearing on working with people and companies that do precisely that on a regular basis.
I think you need to get off the Internets if it compels you to hate people you don't know nor will ever meet.
As to the technical issue at hand, if you disagree, or are hell bent on continuing to try to prove it, more power to you. You have more work to do.
I think the 3.8L is the superior motor, and no amount of ChriVism is going to change that.
Quote from: sportyaccordy on June 11, 2009, 10:50:46 AM
So because you're more experienced + educated ppl can't tell you you're wrong? Whose indulging in the sin of hubris here?
Sure they can, and I welcome it, but they have to be right about me being wrong first.
Quote from: HEMI666 on June 11, 2009, 08:46:01 AM
I doubt my car would. It doesn't like 6th gear much below 55 mph.
My car's definitely happier in that regard, thanks to the turbo. Down to 40, it'll still pull in 6th, but I've set off in 6th from 30 and still kept up with traffic. Fucking slowpokes! :banghead:
Quote from: MrH on June 11, 2009, 10:00:27 AM
You're going to cite a fictional novel for your manufacturing knowledge?
You gotta be kidding me man. Parallel processing helps a lot when it comes to change over times and the such, but it is not a necessity. If anything, not being to able complete the work on the valve train until the heads are on the engine will simply increase the amount of product being worked at once.
If you seriously think that's the only reason why Toyota is so efficient, you don't have a fucking clue what you're talking about.
http://www.amazon.com/Lean-Manufacturing-Plant-Floor-Guide/dp/0872635252 Try reading that instead.
:banghead:
Supply chain flashback. I think I'm having a seizure. Bloody Toyota.
Quote from: GoCougs on June 11, 2009, 10:39:00 AM
This simply means I'm much smarter and infinitely more practiced than you in these things.
Being knowledgeable and being intelligent are two different things. Never forget that.
Quote from: GoCougs on June 11, 2009, 10:39:00 AM
Here's some advice: The Goal is required reading at many a large, high-volume manufacturer (such as my former well-known mulit-national employer, plus GE, Intel and many others), the MBA program I attended (and many others), and in the summer class (http://ocw.mit.edu/OcwWeb/Sloan-School-of-Management/15-760AOperations-ManagementSpring2002/Syllabus/) I took at MIT.
The fact remains it's a fictional novel written in 1984 and not even about the car industry. I don't give a shit if Shigeo Shingo performs fellatio on the book nightly, it still is a fictional story, and if you're seriously going to try and cite that for the bullshit you're hurling on this forum, no one is going to take you seriously
Here's more advice: Beware the sin of hubris. I'm a practicing, licensed engineer with an MBA in tech and mfg management, with 13 years' experience in factory design and management, and you're an undergrad college student. This simply means I'm much smarter and infinitely more practiced than you in these things.
Wow. A little modest are we? You know what, there's an infinite number of engineers out there who are absolute morons. Engineers who have worked in the field for years. Just because you're old doesn't mean you're smart. There are practicing engineers in this very thread who disagree with you. Stop being such a pompous ass because you're old. None of what you have pointed to has shown you have any experience in the car industry or car manufacturing. The simple fact you are comparing the final price of GM vs. Toyota trucks as evidence that the cost to manufacture the engines are equivalent shows how ridiculous you're being.
I'd like to think if all you say is true in terms of your experience, you wouldn't say such stupid things, but time and time again you're proving me wrong. Forget the fact that per employee, GM was paying out the ass compared to Toyota. Forget the fact that their entire manufacturing was horribly inefficient. In fact, let's just forget the whole fucking truck except the engine, and then compare the final prices. Sure, that'll be a good indicator of which type of engine is more expensive to manufacture :rolleyes:
So with that unpleasantness out of the way, I was not commenting on the success whole of the world's largest and most successful manufacturer. I essentially merely commented as to the advantages of sub assemblies in manufacturing, something that even the greenest operations management student should have picked up on.
This is what you said: "It is obvious the OHC engine has more DM in that there is simply more material. However, DL is very much in question. Of note, the valve train on a push rod engine cannot be completed (installation of push rods and rockers, and their adjustment) until the heads are on the engine."
I never said it wasn't advantageous. However, direct material is very important, and you're wrong by stating that parallel processes will affect direct labor. The same amount of man-hours will be necessary whether the heads are on the engine or not when completing such installations. The fact remains that it takes the same amount of time to complete the tasks. The only thing parallel processing would help with is to decrease the amount of engines being worked at simultaneously, which I consider not nearly as important as the amount of direct material being used.
If you really want to try and put yourself above everyone else by being an old engineer, let me remind you what I'm currently working. I work with BMW at one of their newest manufacturing facilities that is also the benchmark for the rest of their facilities. I work directly with their manufacturing department, discussing the implimentation of lean processing in their plant, and comparing their processes to various other plants that I have been to. I've taken classes on the lean process and how it relates to the car industry. All of this is far more applicable to the discussion at hand than a fictional book that business school made you read. If you really want to trick yourself into thinking you're more educated by throwing out MIT, go for it. But I don't think you're fooling anyone. Nothing you've said points to you having any idea about the actual car industry.
As to your critique; "complete the work on the valve train?" I think you're missing some basic technical aspects of the two valve train configurations.
You know exactly what I'm talking about, and I used pretty similar terminology that you did. If you are really going to try and question my knowledge, go for it, but you and I both know that I know what I'm talking about. If that's the best stab you can take at me, instead of defending your position properly, I think it's clear this conversation doesn't need to go any further.
MrH I think you've got a mountain of learning and growing up to. And pick up that book. Good luck.
Quote from: Raza on June 11, 2009, 11:08:23 AM
Being knowledgeable and being intelligent are two different things. Never forget that.
"(I)n these things" implied the former. I've never claimed to be particularly intelligent.
Quote from: GoCougs on June 11, 2009, 11:53:55 AM
MrH I think you've got a mountain of learning and growing up to. And pick up that book. Good luck.
....really, that's it? :confused:
Quote from: GoCougs on June 11, 2009, 11:56:52 AM
"(I)n these things" implied the former. I've never claimed to be particularly intelligent.
Just wanted to clarify--not that I think you're stupid or anything. It was more for the whole class than just you.
Should I even bother reading through the whole thread or is this simply a hp/l debate?
Quote from: NomisR on June 11, 2009, 12:13:28 PM
Should I even bother reading through the whole thread or is this simply a hp/l debate?
From what I skimmed, it focuses mostly on power vs. weight and physical size. I saw some HP/L, but not as much as you'd see on an S2000 forum.
It's actually quite an entertaining read.
Quote from: MrH on June 11, 2009, 12:02:36 PM
....really, that's it? :confused:
Okay, being the nice guy that I am, and feeling a bit bad about being a tad snarky earlier, I'll give you some help.
Your assertion that "direct labor" equates only to "man-hours" is simply false. "Direct labor" is labor
cost. This is a fundamental error that made me check out of the "debate."
Sub assembling is one of the most prominent tacks to reduce DL (amongst having many other benefits).
Quote from: GoCougs on June 11, 2009, 12:41:08 PM
Okay, being the nice guy that I am, and feeling a bit bad about being a tad snarky earlier, I'll give you some help.
Your assertion that "direct labor" equates only to "man-hours" is simply false. "Direct labor" is labor cost. This is a fundamental error that made me check out of the "debate."
Sub assembling is one of the most prominent tacks to reduce DL (amongst having many other benefits).
You're such a pompous twat, you know that? To call someone on a minor semantics error when you're using the cost of final products to conclude that one type of component is cheaper to produce is simply ridiculous.
Quote from: NomisR on June 11, 2009, 12:13:28 PM
Should I even bother reading through the whole thread or is this simply a hp/l debate?
565 IIRC tried to debase things there as a critique, yes.
However, there is basic fundamental engineering theory behind it - higher hp/L = less pumping losses/hp = more efficient engine.
Quote from: GoCougs on June 10, 2009, 04:37:49 PM
Uh, they've already been listed; BMW 5.0L V10, M-B 6.2L V8, Porsche 3.8L F6 (and I'm staying well clear of the exotics...)...
How are they superior? All offer similar power, almost certainly weigh more, don't have significant fuel economy advantages, and almost certainly cost more to develop and produce.
I am sure the NVH characteristics are more favorable, but that is only one part of the equation.
Quote from: TBR on June 11, 2009, 12:49:01 PM
You're such a pompous twat, you know that? To call someone on a minor semantics error when you're using the cost of final products to conclude that one type of component is cheaper to produce is simply ridiculous.
First, I only stated that I remained unconvinced that push rod engines are materially less expensive to produce judging both on the cost of the overall product (vehicle) as well as having knowledge of manufacturing processes and principals. I "concluded" nothing.
Second, it's not semantics if you're trying to play tough guy in the realm of operations management and make a fundamental error that completely defeats the point you're trying to make.
I'm confused. Can I get a rundown of who is on what side? Everyone just seems to be yelling and citing ridiculous stuff. REMEMBER THE BESTEST ENGINE IS THE ONE THAT IS THE BEST.
Quote from: TBR on June 11, 2009, 12:51:09 PM
How are they superior? All offer similar power, almost certainly weigh more, don't have significant fuel economy advantages, and almost certainly cost more to develop and produce.
I am sure the NVH characteristics are more favorable, but that is only one part of the equation.
jesus f'in christ, THEY DO NOT WEIGH MORE!!!!!!
Quote from: GoCougs on June 11, 2009, 01:11:13 PM
First, I only stated that I remained unconvinced that push rod engines are materially less expensive to produce judging both on the cost of the overall product (vehicle) as well as having knowledge of manufacturing processes and principals. I "concluded" nothing.
Second, it's not semantics if you're trying to play tough guy in the realm of operations management and make a fundamental error that completely defeats the point you're trying to make.
The cost of labor and the amount of labor used are directly related last time I checked. :huh:
Quote from: r0tor on June 11, 2009, 01:50:48 PM
jesus f'in christ, THEY DO NOT WEIGH MORE!!!!!!
How can Jesus fuck Christ anyway? Aren't they the same guy, person, boogie man, Sky God or whatever?
Quote from: r0tor on June 11, 2009, 01:50:48 PM
jesus f'in christ, THEY DO NOT WEIGH MORE!!!!!!
Yes they do. The 6.2l LS3 weighs 20 lbs less than the 4.0l M V8. I am not going to find more examples because these numbers are so damn hard to find and I have better things to do.
The LS7 weighs 458lb, the LS2 weighs 10 pound more then that, and the LS1 weighs 10 pound more the that... all 3 weigh more then the 6.2L Mercedes engine
there is no significant weight advantage people
Quote from: r0tor on June 11, 2009, 04:09:23 PM
The LS7 weighs 458lb, the LS2 weighs 10 pound more then that, and the LS1 weighs 10 pound more the that... all 3 weigh more then the 6.2L Mercedes engine
there is no significant weight advantage people
Dims?
Quote from: TBR on June 11, 2009, 01:53:27 PM
The cost of labor and the amount of labor used are directly related last time I checked. :huh:
Ops mgmt 101:
Say it takes 1 minute for an operator to enter the command sequence for an oven and DL rate for the line is $400/hr or $0.11/sec. Said oven can bake up to 6 parts. Oven is full, DL = 10 sec/part = $1.10/part. Oven is half full, DL = 20 sec/part = $2.20/part.
Same "amount" of labor (1 minute), completely different labor cost, aka, DL ($2.22/part vs. $1.11/part).
Quote from: r0tor on June 10, 2009, 05:53:50 AM
10,000 at the most.... and my street car car hit that
No, that is the NASCAR limited range (9300-9600) because of the requirements on transmission and final drive gears ratios.
Quote from: r0tor on June 11, 2009, 04:09:23 PM
The LS7 weighs 458lb, the LS2 weighs 10 pound more then that, and the LS1 weighs 10 pound more the that... all 3 weigh more then the 6.2L Mercedes engine
there is no significant weight advantage people
The number I have seen for the LS3 is 415.
Honestly, I just don't know that there really is a way to settle this for sure since numbers aren't readily available and you can never know what accessories are included in the numbers.
Quote from: hounddog on June 11, 2009, 04:34:28 PM
No, that is the NASCAR limited range (9300-9600) because of the requirements on transmission and final drive gears ratios.
the max engine rpms achieved was around 9800-10,000 (typically in the race they had a 2 step rev cut in the ignition boxes... 9600 and 9800) before nascar restricted the revs... or so one of my former classmates who was an engineer for Petty Enterprises told me a year or two ago
Quote from: sportyaccordy on June 11, 2009, 09:49:00 AM
LS1: 420#
LS7: 458#
MB 6.2: 438#
BMW V10: 528#
BMW V8: 445#
Weight argument is basically out
Quick search of the internets can yield a lot
If you were a car manufacturer and weren't bound by the stigma of tech snobbery you'd be a fool to pick any OHC V8 over an LSx. Beyond having the ability to say 'our engine is cutting edge' there are no immediate benefits
Quote from: sportyaccordy on June 11, 2009, 05:03:00 PM
Quick search of the internets can yield a lot
If you were a car manufacturer and weren't bound by the stigma of tech snobbery you'd be a fool to pick any OHC V8 over an LSx. Beyond having the ability to say 'our engine is cutting edge' there are no immediate benefits
I thought someone had posted some weights, but then I couldn't find them.
Quote from: sportyaccordy on June 11, 2009, 05:03:00 PM
Quick search of the internets can yield a lot
If you were a car manufacturer and weren't bound by the stigma of tech snobbery you'd be a fool to pick any OHC V8 over an LSx. Beyond having the ability to say 'our engine is cutting edge' there are no immediate benefits
yea, torque curves and NVH clearly mean nothing... as does the displacement taxes in europe for the european automakers
Quote from: sportyaccordy on June 11, 2009, 05:03:00 PM
Quick search of the internets can yield a lot
If you were a car manufacturer and weren't bound by the stigma of tech snobbery you'd be a fool to pick any OHC V8 over an LSx. Beyond having the ability to say 'our engine is cutting edge' there are no immediate benefits
Yes, sporty, that's exactly it. A 9/11-Truther type conspiracy - it's all a marketing campaign.
well you it settles it cuz one DOHC engine is light and all the other ones are heavier. Either MB did a great job (which I think they did) or I smell BS. Anyone who thinks that a OHC motor is going to be the same weight and same package size doesn't know cars... regardless of power and what not, pushrods advantage is packaging and weight. You can cry that the MB motor weighs around the same weight as the LS7, but virtually every other reputable DOHC engine is larger and heavier. I bet MB's weight saving was due to materials used. Just like the 422lb claimed engine weight for the Ultimate Aero's 1287hp V8 6.4L, I'm sure it being machined billet aluminum has something to do with it.
And for all the modders out there who have seen/worked on engine swaps that are OHC and OHV will ALL tell you that OHV engines are much smaller in comparison.
If people can't understand that, I give up.
Quote from: r0tor on June 11, 2009, 05:07:59 PM
yea, torque curves and NVH clearly mean nothing... as does the displacement taxes in europe for the european automakers
If you have the $$$$ for an M5 why the fuck would you care about displacement tax
Plus NVH goes completely out the window when M5 owners modify their cars to sound like this
http://www.youtube.com/watch?v=vRYYe0kLCto
You know what you guys are right, this is stupid as hell
Quote from: sportyaccordy on June 11, 2009, 05:35:41 PM
If you have the $$$$ for an M5 why the fuck would you care about displacement tax
Plus NVH goes completely out the window when M5 owners modify their cars to sound like this
http://www.youtube.com/watch?v=vRYYe0kLCto
You know what you guys are right, this is stupid as hell
I jizz in my pants for E60 M5's with the Meisterschaft exhaust... :wub:
M6 is pretty nice, too
http://www.youtube.com/watch?v=OtI0pLFqEkc
Oh I can't believe I forgot this comparo.
Road and Track set out to find the best V8 Exotic, and the best V8.
http://www.roadandtrack.com/article.asp?section_id=31&article_id=6174
"Who makes the best V-8? That's the question we set out to answer.
We all agreed ? without doubt ? that the always hard-hitting LS3 of the Corvette had the best power delivery and was by far the easiest with which to tap its potential.
But everyone also agreed the Ferrari sounded the best. Said Steve, "The F430's engine goes through melodies of sound that start out throaty, move on to a bark and finish in a high-revving scream." It's about as sexy-sounding a package as you'll ever find.
So when it came to choosing an absolute favorite V-8, we were torn: Two of us chose the Corvette's torque-rich 6.2-liter, the other two the Ferrari's high-revving 4.3. In a tie-breaker, we went with the Corvette's LS3. This engine is truly phenomenal in its everyday usability and civility, yet it's insanely fast when you ask it to be ? all the while rewarding our ears with that most American of V-8 thunder."
Man I guess R&T didn't get the memo that OHC's = instant win...
Man, I guess R&T didn't get the memo that to answer the question, Who makes the best V8?, you, um, HAVE TO TEST THEM ALL.
As already proven ad naseum the MB luxury car engine that is the 6.2L uter towers over the LS3...
And the Ferrari was significantly faster and ~10% more powerful (= also towers over the LS3).
Cougs, the 6.2 only towers over the stock offering. Change a couple letters and the LS3 the Z06 uses becomes a Brahma Bull.
And, we should all remember that the DOHC was used extensively in WWII, so it is not "new" any more than anti-lock disc brakes are "new."
I like horsepower, ohc or ohv. As long as I don't have to feed it hay or oats.
They both have advantages and disadvantages. The wanker engine however is superior to both.
Quote from: sportyaccordy on June 11, 2009, 05:35:41 PM
If you have the $$$$ for an M5 why the fuck would you care about displacement tax
Plus NVH goes completely out the window when M5 owners modify their cars to sound like this
http://www.youtube.com/watch?v=vRYYe0kLCto
You know what you guys are right, this is stupid as hell
a sweet exhaust is not NVH
Quote from: GoCougs on June 11, 2009, 09:44:38 PM
Man, I guess R&T didn't get the memo that to answer the question, Who makes the best V8?, you, um, HAVE TO TEST THEM ALL.
As already proven ad naseum the MB luxury car engine that is the 6.2L uter towers over the LS3...
And the Ferrari was significantly faster and ~10% more powerful (= also towers over the LS3).
What test has put the LS3 against the MB 6.2
And how is the Ferrari V8 better than the LSx... by your math it costs 4x as much, and on top of that it has a ridiculous and expensive maintenance schedule($6-8K at every milestone... 15K, 30K, etc). Maybe from a purely technological standpoint it's superior but in the real world not so much.
Quote from: r0tor on June 12, 2009, 05:42:03 AM
a sweet exhaust is not NVH
As awesome as that motor sounds I believe the added
noise does factor into
NVH... making NVH a non-issue for someone looking at a 500HP car
Quote from: r0tor on June 12, 2009, 05:42:03 AM
a sweet exhaust is not NVH
Instead of just talking about theoretical NVH what about real life impressions of NVH?
http://www.caranddriver.com/content/download/141222/1946086/version/1/file/600HP.RESULTS.pdf
Wait what, the ZR1 gets a 9 for NVH. Which ties the inherently balanced V12 from the Lambo, which also gets a 9. Which BEATS the inherently balanced V12 in the Merc, which got an 8. Would think with V12 balance and all that luxury experience, that the Merc would be better on NVH. Where's the OHC magic?
http://www.caranddriver.com/content/download/110303/1496406/version/2/file/USAComparoRESULTS.pdf
Here is another one. The Z06 gets a 9 for NVH. The GT2 does the same 9. The GT-R gets a 7. Where is the OHC magic that gives OHC engines a huge boost in NVH??
And those have been comparisons against European or Japanese cars that frankly do NVH better usually anyway. What about pushrod vs DOHC American style?
http://www.caranddriver.com/content/download/137572/1883211/version/1/file/CorvetteGT500+Results.pdf
Looks like the pushrods win again.
Quote from: r0tor on June 11, 2009, 04:09:23 PM
The LS7 weighs 458lb, the LS2 weighs 10 pound more then that, and the LS1 weighs 10 pound more the that... all 3 weigh more then the 6.2L Mercedes engine
there is no significant weight advantage people
I posted it earlier in the thread...
I have this sitting in my garage:
(http://home.comcast.net/~cvetters3/engine1.jpg)
I spent quite a bit of time walking thorugh salvage yards measuring interesting V8 engines for potential swap use. Toyota, Nissan, BMW, Mercedes, Ford, etc. This one was the physically smallest DOHC V8 I found in my travels, by quite a bit.
It's wider and longer than the cast iron Ford pushrod V8 in the car I have already, and will require modifying the engine compartment to fit it. It's also heavier. I paid to have it shipped to me, and weight was part of the equation. If you want, I can also walk out to my car and measure the 4.4 liter DOHC V8 powering my daily driver (well, I can't weigh it, but if it's physically larger and made of the same materials, well, that's simply physics).
What physical evidence do you have in your garage that you are backing up your strenuous arguing with?
Chris while having the motors sitting in ur garage is a plus, ultimately if that's a requirement to participate in the discussion we might as well close the thread.
Quote from: sportyaccordy on June 12, 2009, 09:38:33 AM
Chris while having the motors sitting in ur garage is a plus, ultimately if that's a requirement to participate in the discussion we might as well close the thread.
He's just stating that he has better information on the subject...and well...he does. And trust me, I'm typing my support for ChrisV through gritted teeth.
Quote from: sportyaccordy on June 12, 2009, 09:38:33 AM
Chris while having the motors sitting in ur garage is a plus, ultimately if that's a requirement to participate in the discussion we might as well close the thread.
Just saying, I'm not basing my part of the discussion on an interesting thought exersize, but on physical evidence. If he's going to argue that the physical evidence is wrong, then I'd expect that he has even better physical evidence to back that up.
Given the same materials, a physically larger chunk of material is going to have more mass, and thus heavier. This is borne out in real world measuring.
There will be exceptions, generally based on exotic materials, and in at least one case, exotic packaging, both of which can jack the cost and complexity up.
Okay:
Yes, OHC engines were rampant in the highest performance applications (fighters, tanks, etc.) during WWII, but then again gas turbines and manned flight have been around since the 19th century, and a I can guarantee you that today a gas turbine-powered flying Camry would be considered "newer" technology.
As to NVH, there is no argument; the additional mass and flex of the push rod valve train is a fundamental detriment. This is one of the principal reasons push rod engines have been all but displaced, even by GM and Chrysler, in the V6 and I4 markets.
The Ferrari 4.3L V8 is a superior engine to the LS3; if Ferrari built 1,000,000+ derivatives a year like GM, it wouldn't cost nearly as much.
This size/weight issue is irrelevant; sometimes that comes with superior technology; and as already proven it's a non-issue when a DOHC V6 can be thrown in a Rav4 or Altima or a DOHC V8 can be thrown in an RS4 or IS-F.
Quote from: ChrisV on June 12, 2009, 09:31:37 AM
I posted it earlier in the thread...
I have this sitting in my garage:
I spent quite a bit of time walking thorugh salvage yards measuring interesting V8 engines for potential swap use. Toyota, Nissan, BMW, Mercedes, Ford, etc. This one was the physically smallest DOHC V8 I found in my travels, by quite a bit.
It's wider and longer than the cast iron Ford pushrod V8 in the car I have already, and will require modifying the engine compartment to fit it. It's also heavier. I paid to have it shipped to me, and weight was part of the equation. If you want, I can also walk out to my car and measure the 4.4 liter DOHC V8 powering my daily driver (well, I can't weigh it, but if it's physically larger and made of the same materials, well, that's simply physics).
What physical evidence do you have in your garage that you are backing up your strenuous arguing with?
It seems to me the ford pushrod smallblock is a far superior engine to that POS OHC engine and you should have never bought it
Quote from: r0tor on June 12, 2009, 09:59:28 AM
It seems to me the ford pushrod smallblock is a far superior engine to that POS OHC engine and you should have never bought it
Touchy touchy
Quote from: r0tor on June 12, 2009, 09:59:28 AM
It seems to me the ford pushrod smallblock is a far superior engine to that POS OHC engine and you should have never bought it
:lol:
Quote from: GoCougs on June 11, 2009, 04:28:10 PM
Ops mgmt 101:
Say it takes 1 minute for an operator to enter the command sequence for an oven and DL rate for the line is $400/hr or $0.11/sec. Said oven can bake up to 6 parts. Oven is full, DL = 10 sec/part = $1.10/part. Oven is half full, DL = 20 sec/part = $2.20/part.
Same "amount" of labor (1 minute), completely different labor cost, aka, DL ($2.22/part vs. $1.11/part).
Ok, so let's get this straight. Let's say you're not a fucking idiot, and you wait until you have a full batch to put in the oven before you start whatever heat treatment needs to be done. Then you have the exact same labor costs. And what would be the downside of doing this?
Hmmm, let's see....oh, that's right. Exactly what I fucking said in the beginning:
" The only thing parallel processing would help with is to decrease the amount of engines being worked at simultaneously, which I consider not nearly as important as the amount of direct material being used."
(Not doing parallel processing) "will simply increase the amount of product being worked at once."
The fact remains that the two manufacturing methods being discussed would have the same takt time, only one would have a slightly larger buffer stock between two processes.
And because you're being an ass hat by trying to quote your class in the process and somehow put yourself above us, I will do the same: Industrial Engineering 408 - Lean Process Manufacturing.
And please, don't try to mention a summer class at MIT like you're hot shit. Summer classes at MIT are open admittance. Anyone with a fucking pulse can take that. And let me remind you, you're still drawing from a fictional novel from a business class.
You barked up the wrong tree.
Quote from: r0tor on June 12, 2009, 09:59:28 AM
It seems to me the ford pushrod smallblock is a far superior engine to that POS OHC engine and you should have never bought it
Actually, the SB Ford is the superior, logical engine for the application: it fits with no mods, is cheaper to modify and make power out of, and won't get me kicked out of the Ford meets. :lol: But, it's been done to death and is the common engine in Falcon/Comet/Mustang builds. I like being different, which is why I'm also taking the extra effort to install the Toyota 5 speed (since the engine was never available with a manual trans, and the car itself came stock with an automatic).
And the Toyota engine, with the crap removed and polished up will look very exotic in the engine bay:
(http://home.comcast.net/~cvetters3/engine3.jpg)
Of course, if I can't get the trans to mate up properly (already bought and sold one expensive adapter kit that simply failed to work right), and get the engine management system to work in stand-alone mode, then I'll probably go back to the SB Ford engine similar to the one in my RX7. Adding complexity and cost just for the "cool" factor ceases to be worth it at some point, especially when the final hp figure would be about the same.
edit...
BTW, I never said DOHC engines were a POS, unlike OHC fanbois that say pushrods are a POS. I happen to like
both (I realize that that's a foreign concept to people who define themsevles by what cars they hate), but I know from experience that the DOHC V8s, at least in mass produced form, are physically larger, heavier when made from the same materials, and generally more costly to make, buy, and build.
Quote from: MrH on June 12, 2009, 12:44:04 PM
Ok, so let's get this straight. Let's say you're not a fucking idiot, and you wait until you have a full batch to put in the oven before you start whatever heat treatment needs to be done. Then you have the exact same labor costs. And what would be the downside of doing this?
Hmmm, let's see....oh, that's right. Exactly what I fucking said in the beginning:
" The only thing parallel processing would help with is to decrease the amount of engines being worked at simultaneously, which I consider not nearly as important as the amount of direct material being used."
(Not doing parallel processing) "will simply increase the amount of product being worked at once."
The fact remains that the two manufacturing methods being discussed would have the same takt time, only one would have a slightly larger buffer stock between two processes.
And because you're being an ass hat by trying to quote your class in the process and somehow put yourself above us, I will do the same: Industrial Engineering 408 - Lean Process Manufacturing.
And please, don't try to mention a summer class at MIT like you're hot shit. Summer classes at MIT are open admittance. Anyone with a fucking pulse can take that. And let me remind you, you're still drawing from a fictional novel from a business class.
You barked up the wrong tree.
Quote
"The only thing parallel processing would help with is to decrease the amount of engines being worked at simultaneously, which I consider not nearly as important as the amount of direct material being used."
"The only thing?" That's not necessarily always true by any means.
I primarily mentioned MIT in that if the world's best engineering institution uses the book in its ops management courses, it ain't chicken feed.
You've botched a fundamental definition (that DL = "man-hours"), don't seem to understand the benefits of such a fundamental characteristic as sub assembling, and I question your implied understanding of takt time.
The only barking is coming from you.
Quote from: GoCougs on June 12, 2009, 05:10:05 PM
"The only thing?" That's not necessarily always true by any means.
I primarily mentioned MIT in that if the world's best engineering institution uses the book in its ops management courses, it ain't chicken feed.
You've botched a fundamental definition (that DL = "man-hours"), don't seem to understand the benefits of such a fundamental characteristic as sub assembling, and I question your implied understanding of takt time.
The only barking is coming from you.
Wow, way to avoid everything I posted.
Direct labor was never a term used in my technical, engineering class on manufacturing. I'm sorry your open enrollment, 101 business class uses different terms than I am used to. Clearly you are smarter, and consequently, you rightly avoided everything I had to say. :rolleyes:
Quote from: sportyaccordy on June 12, 2009, 09:38:33 AM
Chris while having the motors sitting in ur garage is a plus, ultimately if that's a requirement to participate in the discussion we might as well close the thread.
It can be the Chris V and Hotrodalex thread. :lol:
Quote from: MrH on June 12, 2009, 06:53:59 PM
Wow, way to avoid everything I posted.
Direct labor was never a term used in my technical, engineering class on manufacturing. I'm sorry your open enrollment, 101 business class uses different terms than I am used to. Clearly you are smarter, and consequently, you rightly avoided everything I had to say. :rolleyes:
That's just it, you didn't post anything that wasn't already called out.
I'm lost as to how you've taken a 400-level lean manufacturing class (as such a thing precludes a number of lower level industrial and manufacturing engineering classes) and not heard of such a fundamental term as DL (now I don't believe you understand takt time - neither it, like"man-hours," is DL), especially in light of the assertion of knowledge of DM (the two go hand in hand).
Had I not injured my back these posts would have been made from a Japanese factory; ultimately I guess you didn't realize before your tirade that I do a lot of work in Japan (you know, the whole Japanese/TPS/lean connection thingy?). I hope the irony is not lost.
You're so angry you're not stopping to take a breath to realize how little you know. You tried to talk the lingo and have slowly gotten called out in the process, escalating yourself into a frenzy. I don't doubt you have some knowledge but fundamental gaps remain.
Quote from: GoCougs on June 13, 2009, 12:39:08 AM
That's just it, you didn't post anything that wasn't already called out.
I'm lost as to how you've taken a 400-level lean manufacturing class (as such a thing precludes a number of lower level industrial and manufacturing engineering classes) and not heard of such a fundamental term as DL (now I don't believe you understand takt time - neither it, like"man-hours," is DL), especially in light of the assertion of knowledge of DM (the two go hand in hand).
Had I not injured my back these posts would have been made from a Japanese factory; ultimately I guess you didn't realize before your tirade that I do a lot of work in Japan (you know, the whole Japanese/TPS/lean connection thingy?). I hope the irony is not lost.
You're so angry you're not stopping to take a breath to realize how little you know. You tried to talk the lingo and have slowly gotten called out in the process, escalating yourself into a frenzy. I don't doubt you have some knowledge but fundamental gaps remain.
Oh wise GoCougs, when will you ever answer my post? That's all I ask. I never claimed takt time was DL either.
But please, I'd like to hear a rebuttal.
This is just getting sad to watch.
Quote from: MrH on June 13, 2009, 03:20:45 AM
Oh wise GoCougs, when will you ever answer my post? That's all I ask. I never claimed takt time was DL either.
But please, I'd like to hear a rebuttal.
This is just getting sad to watch.
I keep doing so - in the least, you got definition(s) wrong (DL = "man-hour"), you don't understand basic concepts such as sub assemblies ("the only thing..."), you've made unsupported assumptions ("I consider..."), and now claim to have never heard of the term "DL." I also question your usage of "takt time" and the what you claim to be the sole attribute/byproduct in and of itself that is "slightly larger buffer stock."
You're simply a screaming toddler that can't handle getting called out. No amount of Internetry on this side is going to solve that. You simply need to grow up.
Here's a simple question.
What disadvantages do LSx engines have resulting from the use of pushrods?
Quote from: hotrodalex on June 13, 2009, 02:29:07 PM
Here's a simple question.
What disadvantages do LSx engines have resulting from the use of pushrods?
Inability to independantly phase intake and exhaust valve timing due to a single cam
Greater reciprocating mass in the valvetrain (makes valve float an issue at higher RPMs, limiting how high the motor can ultimately rev)
2 valve heads do not breath as well as 3 or 4 valve heads
I think flat heads are the way to go. I mean, really, who needs rocker arms? They just add so much weight.
Quote from: MX793 on June 13, 2009, 04:19:38 PM
Inability to independantly phase intake and exhaust valve timing due to a single cam
Greater reciprocating mass in the valvetrain (makes valve float an issue at higher RPMs, limiting how high the motor can ultimately rev)
2 valve heads do not breath as well as 3 or 4 valve heads
But do those things affect how the engine performs compared to other DOHC engines?
Quote from: hotrodalex on June 13, 2009, 04:29:29 PM
But do those things affect how the engine performs compared to other DOHC engines?
-Variable valve timing on both intake and exhaust can broaden your torque curve, allowing greater power production
-Power = Torque x RPM, so the higher you can rev while still making torque, the more power you can make.
-The better an engine can breath, the greater the volumetric efficiency and the more power and torque it will make at a given RPM.
If the LSx motor was DOHC with VVT (let alone variable lift on top of that) and 4 valve heads, it wouldn't need a supercharger to be making 600+ hp while still being perfectly streetable as a daily driver.
Quote from: NACar on June 13, 2009, 04:24:34 PM
I think flat heads are the way to go. I mean, really, who needs rocker arms? They just add so much weight.
The flathead design does have its elegance, to be sure.
I wonder if such "debates" raged as push rod engines displaced flatheads in the '50s...
Onward with the debate...
Pushrod engines with variable valve timing: http://www.sae.org/automag/technewsletter/070402Powertrain/04.htm
Quote from: NACar on June 13, 2009, 04:24:34 PM
I think flat heads are the way to go. I mean, really, who needs rocker arms? They just add so much weight.
Flat heads are the coolest engines.
Quote from: MX793 on June 13, 2009, 04:55:31 PM
-Variable valve timing on both intake and exhaust can broaden your torque curve, allowing greater power production
-Power = Torque x RPM, so the higher you can rev while still making torque, the more power you can make.
-The better an engine can breath, the greater the volumetric efficiency and the more power and torque it will make at a given RPM.
If the LSx motor was DOHC with VVT (let alone variable lift on top of that) and 4 valve heads, it wouldn't need a supercharger to be making 600+ hp while still being perfectly streetable as a daily driver.
But would they be able to fit in the Corvette?
Would hot rodders still flock to them as one of the choice engines for street machines?
Quote from: hotrodalex on June 13, 2009, 07:36:11 PM
Flat heads are the coolest engines.
Except for the V8's, which have some cooling issues due to the exhaust ports that have to go around the cylinders.
Quote from: NACar on June 13, 2009, 07:32:21 PM
Onward with the debate...
Pushrod engines with variable valve timing: http://www.sae.org/automag/technewsletter/070402Powertrain/04.htm
It's interesting, but it doesn't vary intake timing, and has nothing to do with variable lift; something you'd both find in a bread-n-butter Honda or Toyota.
VVT/L is not the sole dominion of OHC engines however; given enough time and effort, you'd see all that on a push rod engine as well.
I think it unlikely that the precious few automakers who still make them would bother; the development dollars are best spent migrating over to the inherently better OHC platform (like everyone else).
Quote from: GoCougs on June 13, 2009, 07:43:40 PM
It's interesting, but it doesn't vary intake timing, and has nothing to do with variable lift; something you'd both find in a bread-n-butter Honda or Toyota.
VVT/L is not the sole dominion of OHC engines however; given enough time and effort, you'd see all that on a push rod engine as well.
I think it unlikely that the precious few automakers who still make them would bother; the development dollars are best spent migrating over to the inherently better OHC platform (like everyone else).
Chrysler Group did look at a dual overhead-cam arrangement to advance the Viper V10 performance, but it simply would not fit.What can you do? Make the Viper wider? LOL. Huge "power bulges" in the hood for the OHC? LOL.
Also:
GM has a small-block V8 in development with variable intake- and exhaust-valve timing in a three-valve configuration. We may not see a four-valve pushrod gasoline engine, despite use of that valvetrain in diesel V8s.
Quote from: NACar on June 13, 2009, 07:47:30 PM
Chrysler Group did look at a dual overhead-cam arrangement to advance the Viper V10 performance, but it simply would not fit.
What can you do? Make the Viper wider? LOL. Huge "power bulges" in the hood for the OHC? LOL.
Quote from: NACar on June 13, 2009, 07:49:56 PM
Also:
GM has a small-block V8 in development with variable intake- and exhaust-valve timing in a three-valve configuration. We may not see a four-valve pushrod gasoline engine, despite use of that valvetrain in diesel V8s.
No no no, those are all lies! OHC rules and pushrods will always be as ancient as dinosaurs!
Quote from: MX793 on June 13, 2009, 04:55:31 PM
If the LSx motor was DOHC with VVT (let alone variable lift on top of that) and 4 valve heads, it wouldn't need a supercharger to be making 600+ hp while still being perfectly streetable as a daily driver.
So you are saying if the LSX went DOHC with VVT it would suddenly become some 600hp+ monster?
Okay how many 6.2 liter naturally aspirated production car DOHC V8's are there out there that make 600+ hp?
The 6.2L AMG motor is claimed to be the most powerful naturally aspirated V8 in the world, though we established it only puts down about 20-40hp more to the ground than the LS3, and 40-60hp less than the LS7 V8.
If putting DOHC and VVT on an LSX suddenly allows it to make 100hp more than the 6.2 AMG motor, then AMG better turn in their engine building business and start selling lemonade.
Quote from: 565 on June 13, 2009, 07:59:11 PM
The 6.2L AMG motor is claimed to be the most powerful naturally aspirated V8 in the world, though we established it only puts down about 20-40hp more to the ground than the LS3, and 40-60hp less than the LS7 V8.
:facepalm:
Quote from: r0tor on June 13, 2009, 08:03:10 PM
:facepalm:
Do you have proof otherwise?
We already discussed this, during which you earned alot of :facepalm:
Quote from: ChrisV on June 12, 2009, 12:46:37 PM
but I know from experience that the DOHC V8s, at least in mass produced form, are physically larger, heavier when made from the same materials, and generally more costly to make, buy, and build.
its great your experience is more accurate then a scale... i officially give up
Quote from: 565 on June 13, 2009, 08:06:43 PM
Do you have proof otherwise?
We already discussed this, during which you earned alot of :facepalm:
first of all, its completely useless to compare dyno sheets from different dynos. secondly a chassis dyno measure engine output minus drivetrain losses... the difference between a manual tranny and automatic can be as much as 5% in drivetrain losses and in addition the benz will use much heavier components due to being a luxury cruiser concerned with NVH and hauling around a much bigger and heavier car
Quote from: NACar on June 13, 2009, 07:47:30 PM
Chrysler Group did look at a dual overhead-cam arrangement to advance the Viper V10 performance, but it simply would not fit.
What can you do? Make the Viper wider? LOL. Huge "power bulges" in the hood for the OHC? LOL.
I don't buy that; Ferrari fits a 600+hp DOHC engine under the hood of its GTs just fine, and plenty of other low(er)-slung GT/sports cars carry on just fine with DOHC engines under their hoods, too (XLR, Aston Martin, Maserati, etc.).
If so, boo on Chrysler and its lack of chassis prowess, not boo on the engine technology pretty much the rest of the world uses...
Quote from: GoCougs on June 13, 2009, 08:10:35 PM
I don't buy that; Ferrari fits a 600+hp DOHC engine under the hood of its GTs just fine, and plenty of other low(er)-slung GT/sports cars carry on just fine with DOHC engines under their hoods, too (XLR, Aston Martin, Maserati, etc.).
If so, boo on Chrysler and its lack of chassis prowess, not boo on the engine technology pretty much the rest of the world uses...
Ferrari does not have an 8.4 liter DOHC V10, last time I checked.
Quote from: 565 on June 13, 2009, 07:59:11 PM
So you are saying if the LSX went DOHC with VVT it would suddenly become some 600hp+ monster?
Okay how many 6.2 liter naturally aspirated production car DOHC V8's are there out there that make 600+ hp?
The 6.2L AMG motor is claimed to be the most powerful naturally aspirated V8 in the world, though we established it only puts down about 20-40hp more to the ground than the LS3, and 40-60hp less than the LS7 V8.
If putting DOHC and VVT on an LSX suddenly allows it to make 100hp more than the 6.2 AMG motor, then AMG better turn in their engine building business and start selling lemonade.
I mention volumetric efficiency; the AMG is inherently the more powerful engine platform as it simply can move more air.
Also, the AMG 6.2L is a luxury car engine, not a balls-out sports car engine.
As I've already mentioned (and proven elsewhere) chassis dyno comparison doesn't work so hot; the only proper comparison is an engine dyno.
Quote from: r0tor on June 13, 2009, 08:09:55 PM
first of all, its completely useless to compare dyno sheets from different dynos. secondly a chassis dyno measure engine output minus drivetrain losses... the difference between a manual tranny and automatic can be as much as 5% in drivetrain losses and in addition the benz will use much heavier components due to being a luxury cruiser concerned with NVH and hauling around a much bigger and heavier car
Okay if one dyno chart reads higher than another it might be chance. If every dyno chart consistently reads higher, then it's not chance anymore.
I posted an auto dyno for the Corvette and despite the car have only 6 miles on it, the difference still cannot account for the 40-60hp difference between the LS7 and the 6.2 AMG.
The stuff about heavier drivetrain components is just speculation. Did anyone weigh the components from both cars to see? The LS7's drivetrain components also have to deal with the shock and abuse of being hooked up to a manual tranny while Mercedes makes sure its more powerful engines are always cushioned with an automatic. You can always reason both sides without proof. Without data on actual component weights, it's just speculation.
Quote from: NACar on June 13, 2009, 07:32:21 PM
Onward with the debate...
Pushrod engines with variable valve timing: http://www.sae.org/automag/technewsletter/070402Powertrain/04.htm
Yes, I'm well aware that Dodge effectively turned the Viper V10 pushrod into a twin cam motor to get independant intake and exhaust phasing. And I'm quite sure that's an expensive piece of kit to implement.
Quote from: NACar on June 13, 2009, 07:47:30 PM
Chrysler Group did look at a dual overhead-cam arrangement to advance the Viper V10 performance, but it simply would not fit.
What can you do? Make the Viper wider? LOL. Huge "power bulges" in the hood for the OHC? LOL.
Trying to retrofit DOHC heads onto the existing 8.3L engine probably wouldn't fit. Then again, with better breathing heads, they could make the same power with less displacement, meaning they could use a smaller bottom end which buys more space for bigger heads.
Quote from: NACar on June 13, 2009, 08:14:36 PM
Ferrari does not have an 8.4 liter DOHC V10, last time I checked.
EXACTLY. They don't need 8.4L.
The Ferrari V12 will be little shorter owing to the smaller angle between banks (65 vs 90 for Viper) even given the shorter stroke, and we all know the V12 is going to be much longer as well.
Quote from: 565 on June 13, 2009, 08:23:47 PM
The stuff about heavier drivetrain components is just speculation. Did anyone weigh the components from both cars to see? The LS7's drivetrain components also have to deal with the shock and abuse of being hooked up to a manual tranny while Mercedes makes sure its more powerful engines are always cushioned with an automatic. You can always reason both sides without proof. Without data on actual component weights, it's just speculation.
LS7 valves are much larger. There are also push rods and rocker arms. All this additional mass per valve needs beefier valve springs. Further, a push rod valve train has less stiffness owing to the push rods and rocker arms.
There is no cushioning via the transmission; only acceleration and deceleration of the drive train, which is a function of the engine. Stress of the valve train is greatest in terms of shock when revving unloaded (i.e., quickest engine acceleration).
Quote from: GoCougs on June 13, 2009, 09:20:41 PM
LS7 valves are much larger. There are also push rods and rocker arms. All this additional mass per valve needs beefier valve springs. Further, a push rod valve train has less stiffness owing to the push rods and rocker arms.
There is no cushioning via the transmission; only acceleration and deceleration of the drive train, which is a function of the engine. Stress of the valve train is greatest in terms of shock when revving unloaded (i.e., quickest engine acceleration).
Huh who mentioned valvetrains? My post was in response to Rotor's speculation that the Merc's power gap was due to "much heavier components" in the drivetrain. Until someone sticks them on a scale, it's just speculation.
Quote from: 565 on June 13, 2009, 09:31:21 PM
Huh who mentioned valvetrains? My post was in response to Rotor's speculation that the Merc's power gap was due to "much heavier components" in the drivetrain. Until someone sticks them on a scale, it's just speculation.
The perceived power gap on the dyno may be due to heavier components in the drivetrain. Heavy components don't actually sap power, but can appear to do so when tested on an inertial type chassis dyno (which practically all chassis dynos are) because an inertial dyno does not adjust for the weight/inertia of all of the pieces between the engine output and the wheels. Hence swapping to lighter wheels can register as a power gain on a chassis dyno even though no power was actually gained.
Quote from: GoCougs on June 12, 2009, 09:55:05 AM
Okay:
Yes, OHC engines were rampant in the highest performance applications (fighters, tanks, etc.) during WWII, but then again gas turbines and manned flight have been around since the 19th century, and a I can guarantee you that today a gas turbine-powered flying Camry would be considered "newer" technology.
What is your point here?
Bitches ain't shit?
Quote from: giant_mtb on June 13, 2009, 10:34:12 PM
Bitches ain't shit?
(http://www.the-isb.com/images/UnifiedBitchTheory2.jpg)
LOL.
What the f'ck are "tricks?"
:confused:
LOL
:lol:
Quote from: giant_mtb on June 13, 2009, 10:37:02 PM
LOL.
What the f'ck are "tricks?"
:confused:
It's the second line of the song you quoted. :lol:
Quote from: hounddog on June 13, 2009, 10:07:01 PM
What is your point here?
When a technology is first used doesn't deem it newer or older.
Quote from: MX793 on June 13, 2009, 09:52:43 PM
The perceived power gap on the dyno may be due to heavier components in the drivetrain. Heavy components don't actually sap power, but can appear to do so when tested on an inertial type chassis dyno (which practically all chassis dynos are) because an inertial dyno does not adjust for the weight/inertia of all of the pieces between the engine output and the wheels. Hence swapping to lighter wheels can register as a power gain on a chassis dyno even though no power was actually gained.
Yes - I've mentioned this like four times - chassis dynos blow for relative comparisons for a lot more reasons than just this.
Only brake-torque (water-brake or similar non-inertial) engine dyno is the proper way to go for absolute comparison.
The AMG applications will indeed likely have more inertia - AT with torque converter, and a much longer drive shaft (the Corvette is shorter than a Civic).
Quote from: Minpin on June 13, 2009, 10:41:50 PM
It's the second line of the song you quoted. :lol:
O. :huh: :lol:
Quote from: GoCougs on June 13, 2009, 10:52:57 PM
When a technology is first used doesn't deem it newer or older.
I see.
I was actually speaking to everyone when I posted that, reminding people that OHC is not a "new" or "technologically advanced" type of engine.
It was not directed at you, even though it does appear to have been. Sorry for the misunderstanding.
Quote from: CALL_911 on June 13, 2009, 10:35:05 PM
(http://www.the-isb.com/images/UnifiedBitchTheory2.jpg)
:lol:
Quote from: GoCougs on June 13, 2009, 09:14:00 PM
EXACTLY. They don't need 8.4L.
The Ferrari V12 will be little shorter owing to the smaller angle between banks (65 vs 90 for Viper) even given the shorter stroke, and we all know the V12 is going to be much longer as well.
A Viper with a Ferrari engine is not the same Viper. Not at all.
Quote from: 565 on June 13, 2009, 09:31:21 PM
Huh who mentioned valvetrains? My post was in response to Rotor's speculation that the Merc's power gap was due to "much heavier components" in the drivetrain. Until someone sticks them on a scale, it's just speculation.
My mistake - but the AMG cars will indeed have more inertia (mass is irrelevant, BTW) in their drive trains; not only do they have far longer drive shafts (remember, the Z06 is shorter than a Civic) they also exclusively employ ATs (torque converter, bands, clutches, fluid pump, et al.).
Further, though indeed speculation, I would not doubt that owing to the immense weight disadvantage of the AMG cars using the fully tuned 6.2L (i.e., ~ 900+ lbs heavier) that their drive train bearings and seals are beefier (i.e., more drag) and the rear differential has lower efficiency.
Quote from: hotrodalex on June 14, 2009, 08:43:03 AM
A Viper with a Ferrari engine is not the same Viper. Not at all.
He is completely missing the point, once again.
Quote from: NACar on June 14, 2009, 01:35:39 PM
He is completely missing the point, once again.
Do you honestly believe that adding but 0.25" to the bore and 0.50" to the stroke to the 599GTB V12 (=8.4L) that it would no longer fit? (Meaning, engine displacement does not scale anything close to 1:1 with physical engine size). As it is, the V12 is a much longer engine.
If Mopar said such a thing, Mopar chassis engineers = fail. I however doubt such a thing was ever a considered by Mopar. There are far too few Vipers built, and far too low a price point, to warrant such a thing.
Quote from: GoCougs on June 14, 2009, 02:19:46 PM
Do you honestly believe that adding but 0.25" to the bore and 0.50" to the stroke to the 599GTB V12 (=8.4L) that it would no longer fit? (Meaning, engine displacement does not scale anything close to 1:1 with physical engine size). As it is, the V12 is a much longer engine.
If Mopar said such a thing, Mopar chassis engineers = fail. I however doubt such a thing was ever a considered by Mopar. There are far too few Vipers built, and far too low a price point, to warrant such a thing.
The Viper was designed around that pushrod V-10. The Mopar engineers obviously found it more logical to develop the cam-in-cam variable timing system, rather than completely redesign the chassis of the car just to please the overhead cam elitists like yourself.
Quote from: NACar on June 14, 2009, 02:34:39 PM
The Viper was designed around that pushrod V-10. The Mopar engineers obviously found it more logical to develop the cam-in-cam variable timing system, rather than completely redesign the chassis of the car just to please the overhead cam elitists like yourself.
I don't doubt any of that; but the question remains - then why was it ever under consideration?
Remember, you started all this by claiming that Mopar rejected OHC (the implied "OMG OHC IS SO BIG!" talking point). I doubt they ever did, and hence doubt they claimed they couldn't make an OHC power plant fit.
Quote from: GoCougs on June 14, 2009, 02:59:56 PM
I don't doubt any of that; but the question remains - then why was it ever under consideration?
Remember, you started all this by claiming that Mopar rejected OHC (the implied "OMG OHC IS SO BIG!" talking point). I doubt they ever did, and hence doubt they claimed they couldn't make an OHC power plant fit.
Holy shit. Just read the SAE article. :rolleyes:
Quote from: GoCougs on June 13, 2009, 12:39:08 AM
That's just it, you didn't post anything that wasn't already called out.
I'm lost as to how you've taken a 400-level lean manufacturing class (as such a thing precludes a number of lower level industrial and manufacturing engineering classes) and not heard of such a fundamental term as DL (now I don't believe you understand takt time - neither it, like"man-hours," is DL), especially in light of the assertion of knowledge of DM (the two go hand in hand).
Had I not injured my back these posts would have been made from a Japanese factory; ultimately I guess you didn't realize before your tirade that I do a lot of work in Japan (you know, the whole Japanese/TPS/lean connection thingy?). I hope the irony is not lost.
You're so angry you're not stopping to take a breath to realize how little you know. You tried to talk the lingo and have slowly gotten called out in the process, escalating yourself into a frenzy. I don't doubt you have some knowledge but fundamental gaps remain.
You've still yet to prove me wrong.
What you said:
Quote from: GoCougs on June 10, 2009, 04:51:44 PM
[T]he valve train on a push rod engine cannot be completed (installation of push rods and rockers, and their adjustment) until the heads are on the engine. With an OHC engine, the valve train can be fully assembled independent of the engine, save for the timing chain/belt. When one is building a few engines the difference is small, however when one is building 200,000 - 750,000 such engines a year, the manufacturing efficiency (i.e., parallel tasking) is substantial.
And you provided said example:
Quote from: GoCougs on June 11, 2009, 04:28:10 PM
Ops mgmt 101:
Say it takes 1 minute for an operator to enter the command sequence for an oven and DL rate for the line is $400/hr or $0.11/sec. Said oven can bake up to 6 parts. Oven is full, DL = 10 sec/part = $1.10/part. Oven is half full, DL = 20 sec/part = $2.20/part.
Same "amount" of labor (1 minute), completely different labor cost, aka, DL ($2.22/part vs. $1.11/part).
I simply said, if you're not an idiot, and just watch until entire batch sizes, the only downside to not being able to assemble the valve train until the head is on the engine is a slight increase in inventory between processes. This small increase in inventory between processes is still less costly than the added material cost of the OHC engine.
You haven't said anything yet to prove that wrong. Nothing. I will say, you're better spoken than I am. But you've done nothing but try to belittle me by arguing semantics with every post instead of actually showing me how I'm wrong.
Your pompous attitude is tiring. Bring something else to the table for once. Please.
Quote from: GoCougs on June 14, 2009, 02:59:56 PM
I don't doubt any of that; but the question remains - then why was it ever under consideration?
To please pricks like you.
Quote from: hotrodalex on June 14, 2009, 05:14:20 PM
To please pricks like you.
And the rest of the planet's automakers as well I presume (well, save for GM)?
I think I just found the answer as to it wouldn't "fit;" the Viper uses a wet sump system; something I never, ever would have guessed.
Nonetheless, mention of the Viper was completely irrelevant in the first place.
Quote from: GoCougs on June 14, 2009, 05:38:37 PM
And the rest of the planet's automakers as well I presume (well, save for GM)?
I think I just found the answer as to it wouldn't "fit;" the Viper uses a wet sump system; something I never, ever would have guessed.
Nonetheless, mention of the Viper was completely irrelevant in the first place.
Because a dry sump system would be such an impossible engineering feat if they are already redesigning the engine to use overhead cams. Are you seriously this dense, or are you just having a great time trolling? :nutty
Quote from: NACar on June 14, 2009, 05:46:18 PM
Because a dry sump system would be such an impossible engineering feat if they are already redesigning the engine to use overhead cams. Are you seriously this dense, or are you just having a great time trolling? :nutty
You haven't figured that out by now?
Quote from: MrH on June 14, 2009, 04:50:51 PM
You've still yet to prove me wrong.
What you said:
And you provided said example:
I simply said, if you're not an idiot, and just watch until entire batch sizes, the only downside to not being able to assemble the valve train until the head is on the engine is a slight increase in inventory between processes. This small increase in inventory between processes is still less costly than the added material cost of the OHC engine.
You haven't said anything yet to prove that wrong. Nothing. I will say, you're better spoken than I am. But you've done nothing but try to belittle me by arguing semantics with every post instead of actually showing me how I'm wrong.
Your pompous attitude is tiring. Bring something else to the table for once. Please.
Perhaps think about adding something material to the subject of the thread. The foray into Ops Mgmt 101 has gone (and will go) nowhere.
Quote from: GoCougs on June 14, 2009, 05:54:36 PM
Perhaps think about adding something material to the subject of the thread. The foray into Ops Mgmt 101 has gone (and will go) nowhere.
(http://images.icanhascheezburger.com/completestore/2009/1/23/128772176292004320.jpg)
Quote from: NACar on June 14, 2009, 05:46:18 PM
Because a dry sump system would be such an impossible engineering feat if they are already redesigning the engine to use overhead cams. Are you seriously this dense, or are you just having a great time trolling? :nutty
I'm trying to connect dots on an assertion that is completely unbelievable (that Chrysler considered a DOHC 8.4L V10) that you yourself brought up in effort to trolling with as a support to the semi-irrelevant push rod "Champion of Space Savings" argument.
I will give you props; your attempt has been called but very uncharacteristically you have not gone off the deep end as you often do, rather, that task has been taken up by those not prone to shrillness or unhinged behavior; MrH, 565, hotrodalex, and a few others.
Quote from: NACar on June 14, 2009, 05:46:18 PM
Because a dry sump system would be such an impossible engineering feat if they are already redesigning the engine to use overhead cams. Are you seriously this dense, or are you just having a great time trolling? :nutty
Adapting a pushrod to OHC is hardly a total redesign. Just look at the Ford Cologne engine (the 4.0 V6 in the Mustang and Ranger). The block is basically unchanged, they only changed the heads and then implemented the necessary drive components to turn the cams (which entailed adding a couple of chains, tensioners, and replacing the original in-block cam with a jackshaft). Turning a wet sump into a dry sump would likely be a far more intensive modification.
Quote from: MX793 on June 14, 2009, 06:03:48 PM
Adapting a pushrod to OHC is hardly a total redesign. Just look at the Ford Cologne engine (the 4.0 V6 in the Mustang and Ranger). The block is basically unchanged, they only changed the heads and then implemented the necessary drive components to turn the cams (which entailed adding a couple of chains, tensioners, and replacing the original in-block cam with a jackshaft). Turning a wet sump into a dry sump would likely be a far more intensive modification.
It's not just adapting it - it's adapting it to fit in the same space without making other compromises.
Quote from: MX793 on June 14, 2009, 06:03:48 PM
Adapting a pushrod to OHC is hardly a total redesign. Just look at the Ford Cologne engine (the 4.0 V6 in the Mustang and Ranger). The block is basically unchanged, they only changed the heads and then implemented the necessary drive components to turn the cams (which entailed adding a couple of chains, tensioners, and replacing the original in-block cam with a jackshaft). Turning a wet sump into a dry sump would likely be a far more intensive modification.
So it will need an oil tank and a new pump, some hoses, and put a few new oil pickup points in the engine. Please explain why this is so difficult.
Quote from: GoCougs on June 14, 2009, 06:00:55 PM
I'm trying to connect dots on an assertion that is completely unbelievable (that Chrysler considered a DOHC 8.4L V10) that you yourself brought up in effort to trolling with as a support to the semi-irrelevant push rod "Champion of Space Savings" argument.
I will give you props; your attempt has been called but very uncharacteristically you have not gone off the deep end as you often do, rather, that task has been taken up by those not prone to shrillness or unhinged behavior; MrH, 565, hotrodalex, and a few others.
Oh fuck you, I'll go off the deep end any time I feel like it. Contributing to this debate-thread with the mention of real and valid technolgies is not trolling - trolling is your complete lack of the will to comprehend any opinion or information that you find contradictory to your own.
Let's see what the choices are:
A. GoCougs knows all and SAE is writing phony technical articles
B. GoCougs is a moron
Quote from: NACar on June 14, 2009, 06:15:37 PM
Oh fuck you, I'll go off the deep end any time I feel like it. Contributing to this debate-thread with the mention of real and valid technolgies is not trolling - trolling is your complete lack of the will to comprehend any opinion or information that you find contradictory to your own.
Let's see what the choices are:
A. GoCougs knows all and SAE is writing phony technical articles
B. GoCougs is a moron
Dang it NACar, and you were behaving, too, and I dare so better than most.
I suggest we drop this phantom 8.4L DOHC V10 that NACar brought up. It is simply irrelevant.
This thread blows.
I can't believe it's still going.
Will this ever end?
IT ENDS NOW!
The line must be drawn here. This far, no further!
However, I will not make them pay for what they've done.
Quote from: Onslaught on June 14, 2009, 06:26:36 PM
I can't believe it's still going.
Well I think I kinda continued it. But it was actually intelligent conversation that kind of got some where, thanks to MX793. Then it went back to the previous pointless pissing match about minuscule details that nobody cares about.
Quote from: Onslaught on June 14, 2009, 06:32:54 PM
The line must be drawn here. This far, no further!
However, I will not make them pay for what they've done.
Niiice. :lol:
Is 500HP still 500HP or do they measure OHC/OHV output differently
Quote from: sportyaccordy on June 14, 2009, 09:53:02 PM
Is 500HP still 500HP or do they measure OHC/OHV output differently
Shut up you idiot. Don't you see we tried to end this malarkey?
Uh, it "ended" before Laconian started this thread.
And yes sporty, plainly there is a difference. Push rod engines have more torque, which we all know is actually better than horsepower.
Quote from: GoCougs on June 14, 2009, 10:13:25 PM
Uh, it "ended" before Laconian started this thread.
And yes sporty, plainly there is a difference. Push rod engines have more torque, which we all know is actually better than horsepower.
What's that? It's deer season? No man, that's not for another couple of months.
Quote from: GoCougs on June 14, 2009, 10:13:25 PM
Uh, it "ended" before Laconian started this thread.
And yes sporty, plainly there is a difference. Push rod engines have more torque, which we all know is actually better than horsepower.
Are you this painfully obstinate in real life? What good are qualifications when you're impossible to exchange ideas with..
HP is HP... I am going to do some research but can we agree that the cost of replacing a motor from the dealer is indicative of its cost to make? If anyone thinks an MB 6.2 costs less to replace than an LS6 (fuck it, LS7) please speak now
Quote from: GoCougs on June 14, 2009, 10:13:25 PM
Uh, it "ended" before Laconian started this thread.
And yes sporty, plainly there is a difference. Push rod engines have more torque, which we all know is actually better than horsepower.
Tell that to an F1 engine. I don't think it will understand you. :confused: :lol:
Quote from: Onslaught on June 14, 2009, 06:32:54 PM
The line must be drawn here. This far, no further!
However, I will not make them pay for what they've done.
"It aint over till it's over."
or
"This is like deja vu all over again."
Quote from: sportyaccordy on June 15, 2009, 04:49:05 AM
If anyone thinks an MB 6.2 costs less to replace than an LS6 (fuck it, LS7) please speak now
The LS7 is a $15k engine... not exactly cheap
Quote from: r0tor on June 15, 2009, 05:58:33 AM
The LS7 is a $15k engine... not exactly cheap
What brand new engine is "cheap"? And that's not the issue, the question is whether or not comparably powered OHC motors are less cheap
i'd rather buy a 3 rotor engine swap for $15k then either...
Quote from: sportyaccordy on June 15, 2009, 04:49:05 AM
Are you this painfully obstinate in real life? What good are qualifications when you're impossible to exchange ideas with..
HP is HP... I am going to do some research but can we agree that the cost of replacing a motor from the dealer is indicative of its cost to make? If anyone thinks an MB 6.2 costs less to replace than an LS6 (fuck it, LS7) please speak now
No, which ideas, no, and irrelevant.
The E63 AMG MSRP is $88K.
The M5 MSRP is $86k.
The C63 MSRP is $56k.
The equivalent luxury Z06 (premium package + nav) MSRP is $82k.
Though the Z06 has some expensiveness to it (space frame, torque tube) it has some cheapness too (SMC body panels, low-rent interior even when gussied up) but then again the E63 and M5 have much pricier AT/DSG transmissions. And the C63 is just plain much less expensive. Meaning, unless MB/BMW are taking a bath and Chevy making a mint, I remain unconvinced that there is a material cost difference between the two engines.
Quote from: GoCougs on June 15, 2009, 08:10:01 AM
Meaning, unless MB/BMW are taking a bath and Chevy making a mint, I remain unconvinced that there is a material cost difference between the two engines.
Yeah, because let's forget the idea of labor costs and inefficient manufacturing methods contributing to the final price of the vehicle...
So you think profit margins and material cost are the only things that determine the price of a car?
Don't you wonder why a company that was selling the most vehicles in the entire world in 2007 is now bankrupt?
I have to ask, have you ever stepped into a car manufacturing plant? Have you stepped in multiple plants and looked at how drastically different they can be? Some of the things you say (and by some, I mean most), leads me to believe you have yet to step into an actual car plant.
Quote from: GoCougs on June 14, 2009, 05:54:36 PM
Perhaps think about adding something material to the subject of the thread. The foray into Ops Mgmt 101 has gone (and will go) nowhere.
:rolleyes: Way to
try and dodge a bullet again.
It's not turkey season either! Damn you people are some dense motherfuckers!
Quote from: MrH on June 15, 2009, 02:02:16 PM
Yeah, because let's forget the idea of labor costs and inefficient manufacturing methods contributing to the final price of the vehicle...
So you think profit margins and material cost are the only things that determine the price of a car?
Don't you wonder why a company that was selling the most vehicles in the entire world in 2007 is now bankrupt?
It was indeed not a complete comparison; however, each vehicle's antecedent has scale (i.e., ~40,000 - ~150,000 annual units) and each is made by a full-line automaker, meaning, sporty's cost challenge is easily questioned if not defeated by the C63.
Quote
I have to ask, have you ever stepped into a car manufacturing plant? Have you stepped in multiple plants and looked at how drastically different they can be? Some of the things you say (and by some, I mean most), leads me to believe you have yet to step into an actual car plant.
I have been in a car factory (Subaru - but didn't do any work in it); we can also add to this Freightliner and Paccar (Kenworth, Peterbilt); plus myriad other "transportation product" plants - from single-seat planes, to sea planes, to regional jets, to jumbo jets. I mention other high-volume automated plants, too; from electronic toothbrushes, to food packaging, to semiconductor, to carbon fiber lay-down.
Merely stepping foot into such facilities is means little however (i.e., beware the elixir of automatic knowledge); I have done design/programing on machines in these factories (where I started my career), from there I moved onto the budgeting/design/installation/operation/quality/management of entire assembly lines - and let's not forget the formal training (BSME, MBA, various OJT certifications and courses).
You have none of the above; so where your voice of authority comes from is anyone's guess.
Quote
:rolleyes: Way to try and dodge a bullet again.
You threw down and got caught; how many times can that process go 'round and 'round? It's an appropriate challenge on its own merit, however; you're clinging to a pretty esoteric subject and have not added one scintilla of engineering worth to the discussion.
Quote from: GoCougs on June 15, 2009, 03:10:23 PM
It was indeed not a complete comparison; however, each vehicle's antecedent has scale (i.e., ~40,000 - ~150,000 annual units) and each is made by a full-line automaker, meaning, sporty's cost challenge is easily questioned if not defeated by the C63.
You're giving GM waaaay too much credit. Just because it's a full-line automaker doesn't mean that productions costs would be remotely similar.
Quote from: GoCougs on June 15, 2009, 03:10:23 PM
I have been in a car factory (Subaru - but didn't do any work in it); we can also add to this Freightliner and Paccar (Kenworth, Peterbilt); plus myriad other "transportation product" plants - from single-seat planes, to sea planes, to regional jets, to jumbo jets. I mention other high-volume automated plants, too; from electronic toothbrushes, to food packaging, to semiconductor, to carbon fiber lay-down.
Merely stepping foot into such facilities is means little however (i.e., beware the elixir of automatic knowledge); I have done design/programing on machines in these factories (where I started my career), from there I moved onto the budgeting/design/installation/operation/quality/management of entire assembly lines - and let's not forget the formal training (BSME, MBA, various OJT certifications and courses).
You have none of the above; so where your voice of authority comes from is anyone's guess.
I just finished up my work with BMW today actually in Germany. I've been working with at their plant here in Leipzig now on and off for 6 weeks with the head of one of their quality divisions. We've covered everything there is to do with BMW manufacturing. I've been to other car plants and gone through their manufacturing process in depth too. I've compared these plants in an academic setting with a former GM engineer and now professor, and another professor who specializes in lean process manufacturing, with years of experience both consulting and working for suppliers in the automotive industry. Let's not forget I've taken an entire class on Lean Process Manufacturing in the automotive industry.
I corrected something simple you said. You immediately tried to belittle me, and argue semantics with me. You've yet to show my initial statement was wrong. I'm still looking for an answer.
Stop trying to act all high and mighty, and produce a legitimate answer for once. I've shown time and time again I know what the fuck I'm talking about, so don't talk down to me like a child and don't deserve to hear a legitimate answer out of you.
I didn't get caught. You're simply getting called out, and can't handle it.
Quote from: MrH on June 15, 2009, 03:39:14 PM
You're giving GM waaaay too much credit. Just because it's a full-line automaker doesn't mean that productions costs would be remotely similar.
I just finished up my work with BMW today actually in Germany. I've been working with at their plant here in Leipzig now on and off for 6 weeks with the head of one of their quality divisions. We've covered everything there is to do with BMW manufacturing. I've been to other car plants and gone through their manufacturing process in depth too. I've compared these plants in an academic setting with a former GM engineer and now professor, and another professor who specializes in lean process manufacturing, with years of experience both consulting and working for suppliers in the automotive industry. Let's not forget I've taken an entire class on Lean Process Manufacturing in the automotive industry.
I corrected something simple you said. You immediately tried to belittle me, and argue semantics with me. You've yet to show my initial statement was wrong. I'm still looking for an answer.
Stop trying to act all high and mighty, and produce a legitimate answer for once. I've shown time and time again I know what the fuck I'm talking about, so don't talk down to me like a child and don't deserve to hear a legitimate answer out of you.
I didn't get caught. You're simply getting called out, and can't handle it.
Six weeks' of "on and off" work experience, an "academic setting", an entire class, and bragging about your prof serves to prove only that you hardly any education or experience on the subject. It doesn't say you're stupid or ignorant, but you're getting way carried away.
My own fault - I should have stopped after you botched DL and had never heard of
The Goal, but then again I never expected a self-validating jihad. Now I have to be uncharacteristically not-nice guy as this is getting really, really old - please contribute materially
to the thread or find somewhere else to be.
Quote from: GoCougs on June 15, 2009, 04:04:45 PM
Six weeks' of "on and off" work experience, an "academic setting", an entire class, and bragging about your prof serves to prove only that you hardly any education or experience on the subject. It doesn't say you're stupid or ignorant, but you're getting way carried away.
My own fault - I should have stopped after you botched DL and had never heard of The Goal, but then again I never expected a self-validating jihad. Now I have to be uncharacteristically not-nice guy as this is getting really, really old - please contribute materially to the thread or pound yer chest elsewhere.
?(http://img5.imageshack.us/img5/7229/smallposter.jpg) (http://img5.imageshack.us/i/smallposter.jpg/)
Yes, Minpin, believe it or not we see you.
So then you see the pointlessness of this discussion? Thanks, moving on now on to more important.....HOLY SHIT A BEAR A BIG FUCKING BEAR!
Quote from: GoCougs on June 15, 2009, 04:04:45 PM
Six weeks' of "on and off" work experience, an "academic setting", an entire class, and bragging about your prof serves to prove only that you hardly any education or experience on the subject. It doesn't say you're stupid or ignorant, but you're getting way carried away.
My own fault - I should have stopped after you botched DL and had never heard of The Goal, but then again I never expected a self-validating jihad. Now I have to be uncharacteristically not-nice guy as this is getting really, really old - please contribute materially to the thread or find somewhere else to be.
Oh the belittling, where will it end?
Annnnnnd you avoid answering me as always. Maybe if this thread goes on for another 5 pages, you'll try to defend yourself instead of being an ass.
EDIT: Some experience in car manufacturing is better than none... :huh: :evildude:
Quote from: Minpin on June 15, 2009, 04:28:18 PM
So then you see the pointlessness of this discussion? [ignore Minpin screed]Thanks, moving on now on to more important.....HOLY SHIT A BEAR A BIG FUCKING BEAR![/ignore Minpin screed ]
No, not pointless; it's been educational.
There's a reasons only two of the world's automakers use push rod valve trains in new engine designs and with that
it's only one engine each. The arguments; weight, size, cost, economy, performance, et al., have similarly been waged, and decided, by engine design departments the world over. Push rod engines lost out, as has been explained
ad naseum in this thread.
Quote from: GoCougs on June 15, 2009, 07:52:29 PM
No, not pointless; it's been educational.
There's a reasons only two of the world's automakers use push rod valve trains in new engine designs and with that it's only one engine each. The arguments; weight, size, cost, economy, performance, et al., have similarly been waged, and decided, by engine design departments the world over. Push rod engines lost out, as has been explained ad naseum in this thread.
If your idea of education is learning how to debate, troll-style, then yes it has been 100% educational.
Push rods may be rare in new cars, but to say the LS7 has "lost out" is absolutely wrong as it's one of the best engines in the world.
Quote from: hotrodalex on June 15, 2009, 09:53:04 PM
If your idea of education is learning how to debate, troll-style, then yes it has been 100% educational.
Push rods may be rare in new cars, but to say the LS7 has "lost out" is absolutely wrong as it's one of the best engines in the world.
Agreed with to some degree. I wouldn't necessarily call it one of the best, but it definitely has its merits and its place in the automotive world. It's far from being inferior like GoCougs would like to believe.
I like how we have at least 4 or 5 well informed and educated posters disagreeing with GoCougs at the end of all this, and he's still declaring himself some sort of winner in this debate.
Can I be the winner?
There is no "winner" and there is no "debate." There is only "explanation" of "basic engineering principals."
Fundamental gaps in knowledge abound in the thread. I point to the jihad over inertial dyno testing as a prime example. In general an extremely knowledgeable and level-headed poster simply did not understand (and then ignored) the fundamental concept of inertia.
Other engineering basics such as volumetric efficiency, mechanical bandwidth, and Otto cycle/pumping losses, have been discussed implicitly or explicitly, and similarly have been misunderstood or ignored.
Just because people own cars, like cars, work on cars, read about cars, see cars made in a factory, or otherwise be all about cars, does not provide a ticket to automatic knowledge of how cars work.
Quote from: giant_mtb on June 16, 2009, 05:45:36 AM
Can I be the winner?
no, the winner is clearly the "20B" 3-rotor rotary engine
Quote from: r0tor on June 16, 2009, 09:57:37 AM
no, the winner is clearly the "20B" 3-rotor rotary engine
Rotaries = :facepalm:
Speaking of which I might be buying a rotary powered car...
:orly:
Quote from: r0tor on June 16, 2009, 10:46:20 AM
:orly:
Yeah having multiple cars while attending med school is so unrealistic that I can't believe I pulled it off in my first year. But now that dream probably has to come to an end. I've been juggling parking by parking one in my free assigned spot, begging the landlord to lend me another spot, and then parking one on the street.
I'm thinking of getting rid of everything and buying a used 10-15k car so I'm not totally car-less.
Two of my car's aren't really worth anything. The 1987 Supra's falling apart in every way, and it's probably worth next to nothing. Then there is the 1998 Pathfinder with over 200K miles that was my winter car. The problem is that it has a salvage title, high miles, and isn't worth much now. I take the train to school so there really isn't an urgent need to drive through snow anymore.
The only car worth something is the Z06. I might be able to sell it for 25kish (hopefully). Which isn't that bad cause I paid 32k for it 4 years ago and the economy is shit now.
So I might end up with 10k-15k extra cash in my pocket and alot less to worry about, which makes it the rational choice.
The problem is that I'm an irrational hoarding bastard and I never let go of my cars. The Pathfinder was supposed to replace the Supra after the Supra blew a head gasket, but I missed the fun and fixed and kept the Supra. The Z06 was supposed to REALLY replace the Supra after the Supra developed rod knock, but it became a good project that my father and I worked to rebuild the engine. Then it had sentimental value, so it then got even harder to get rid of :facepalm:. Which is how one single guy ended up with 3 cars... :banghead:
Man just thinking about it makes it hard for me to sell them. I think the only car I don't have an attachment to is the Pathfinder. Shit knowing me I'm probably gonna just take the Supra and put it in storage at my folks place (they've got plenty of space) and daily drive the Z06...maybe.
But if I was to buy a 10-15K car to replace them all, an RX8 would be near the top of the list ( I drove them before and I liked them). I'm seeing pretty low mileage examples on sale for 11-13k. The concern I have is reliability. I'm also thinking about an IS300 or G35.
well in the bright side, all series 1 RX8's engines are warrantied for 7 years or 100,000 miles now. If you find one, get a compression test done on it. If its good, with a little oil premix your golden for years and years and years. If the compression fails, the engine will be replaced by mazda. If its somewhere in the middle, its a gamble...
Quote from: r0tor on June 16, 2009, 11:24:51 AM
well in the bright side, all series 1 RX8's engines are warrantied for 7 years or 100,000 miles now. If you find one, get a compression test done on it. If its good, with a little oil premix your golden for years and years and years. If the compression fails, the engine will be replaced by mazda. If its somewhere in the middle, its a gamble...
Oil premix... you mean adding engine oil to your fuel tank?
a synthetic TCW-3 two stroke oil is very good!
Quote from: r0tor on June 16, 2009, 12:24:05 PM
a synthetic TCW-3 two stroke oil is very good!
So you have to go beyond what the Renesis already adds to the engine?
Quote from: 565 on June 16, 2009, 01:11:48 PM
So you have to go beyond what the Renesis already adds to the engine?
its a topic debated throughout the history of rotary engines it seems. You can trust the OEM system, you can add small amounts of premix on top of the factory system, you can plumb the factory system to draw off of a seperate premix container instead of the motor oil, or just get rid of the oil injection system entirely and run premix only. All positions have their merits...
Quote from: r0tor on June 16, 2009, 01:54:07 PM
its a topic debated throughout the history of rotary engines it seems. You can trust the OEM system, you can add small amounts of premix on top of the factory system, you can plumb the factory system to draw off of a seperate premix container instead of the motor oil, or just get rid of the oil injection system entirely and run premix only. All positions have their merits...
So which one do you do and have you had any engine troubles?
Quote from: r0tor on June 16, 2009, 12:24:05 PM
a synthetic TCW-3 two stroke oil is very good!
Makes sense I guess to give the system as much help as possible. I imagine spark plugs don't last long in these engines? The ash buildup must be insane.
I tried premixing and do from time to time. Also used some fuel additives regularly to combat carbon build-up (the rotary's #1 killer). Didn't notice a big difference with either. I'm going on 60,000 miles and the engine still runs smoothly however I think its probably down 10-20 hp from weaker then desired compression from my observations. There are several RX8's with over 150,000 miles that never premixed and are still running. Then again, some have died after 50,000 miles. Generally the engine failures are concentrated to hot and dry parts of the US where overheating can be a concern.
The short story is on pre-renesis engines, mazda had 1 oil injection nozzle (really a dripper) per rotor located in the dead center of each rotor housing. Historically its been sufficient, but where wear was seen was the corners or each rotors apex seals. For the renesis, Mazda moved to 2 oil squirters per rotor located on each end of the apex seal and drastically cut back the amount of oil injected. On early RX8's premature apex seal wear started occurring in the center of the apex seal. After more then a dozen ECU flashes, mazda upped the oil injection of these engines, had a voluntary recall to check all of the engines in the US, and then extended the warranty to 100,000 miles. On the second gen RX8's, the engine now has 3 oil squirters per rotor for theoretically better distribution of oil.
Premix has always been a popular belief for the rotary engines and for reliability reasons, most if not all race cars remove the oil injection system and just pre-mix a 2 stroke oil... which in theory lubricates better and burns cleaner then motor oil in this application. General consensus is it can't hurt and some rotary tuners like Pettit Racing actually sell little 2oz bottles you can use for a fill-up making it rather easy to do. Common sense tells me there are probably benefits - but if the benefits are actually seen in a typical daily driver are questionable.
...spark plugs should be replaced every year or two as they crap up...
Quote from: r0tor on June 16, 2009, 12:24:05 PM
a synthetic TCW-3 two stroke oil is very good!
Aren't you supposed to use mineral oil for rotary engines?
Quote from: mzziaz on June 16, 2009, 04:37:53 PM
Aren't you supposed to use mineral oil for rotary engines?
Thats what I use in my jet ski.
Quote from: mzziaz on June 16, 2009, 04:37:53 PM
Aren't you supposed to use mineral oil for rotary engines?
In the crank case I've heard that's true, but what he's talking about is oil that you add to the fuel (typically required by 2-stroke engines).
the synthetic in the crank case is old news that continues to be spread to this day... it apparently originated back in the very beginnings of synthetic oils a particular brand did not have a good compatibility with a seal in the engine. Its been fine to use for years now - infact synthetic oil was in the 787B at LeMans and just recently last year in the 24hr Daytona winner
Is this the right place to say that I like very much the twin-turbo Bentley V8 engine?
Quote from: omicron on June 17, 2009, 09:39:31 AM
Is this the right place to say that I like very much the twin-turbo Bentley V8 engine?
Who doesn't? :wub:
Just some more food for thought...
Compared to an OHC which directly actuates the valves, the pushrod layout actually has an advantage: For performance tuning, you can manipulate the rocker angles and ratios to allow for different characteristics in the way the valve is opened (such as the rate of acceleration on the opening and closing flanks, as well as the overall lift achieved). This allows for more valvetrain tuning, compared to an OHC design. With OHC, the only way to alter the valve characteristics is with the cam profile itself - which becomes limited as you get more aggressive.
And of course, the argument against mass in the moving parts is levied against pushrods, yet we can see this in 4 cam V engines:
(http://www.carzi.com/wp-content/uploads/timing-chains-769-big1.jpg)
(http://www.nogaroblue.com/cars/s4v8.jpg)
(http://blog.tmcnet.com/blog/tom-keating/images/Rube%20Goldberg.jpg)
Both layouts are over 100 years old. Both layouts in current form have massive modern metallurgical, manufacturing, and electronic engine management tech thrown at them. Both do their job. Arguing about (and believing) one being better than another is just stupid and just about the worst sort of engineering masturbation.
Quote from: ChrisV on June 18, 2009, 07:48:03 PM
Just some more food for thought...
Compared to an OHC which directly actuates the valves, the pushrod layout actually has an advantage: For performance tuning, you can manipulate the rocker angles and ratios to allow for different characteristics in the way the valve is opened (such as the rate of acceleration on the opening and closing flanks, as well as the overall lift achieved). This allows for more valvetrain tuning, compared to an OHC design. With OHC, the only way to alter the valve characteristics is with the cam profile itself - which becomes limited as you get more aggressive.
OHCs can use rockers as well (and a great many do). In fact, what you've described is exactly how BMW's Valvetronic system works to alter the valve lift (and eliminate the need for a throttle plate), and they do it on the fly (along with independant intake and exhast cam phasing to adjust timing). All VTEC Hondas also use some kind of rocker as well rather than the cam lobe acting directly on the valve.
Would the forum be similarly aghast at the picture of the relatively elegant flathead head versus the Rube'd pushrod head?
Ford flathead:
(http://img200.imageshack.us/img200/2609/flathead.jpg) (http://img200.imageshack.us/i/flathead.jpg/)
Ford small block:
(http://img200.imageshack.us/img200/5513/smallblock.jpg) (http://img200.imageshack.us/i/smallblock.jpg/)
Manipulating rocker angles and ratios can toast the valve guides or lead to a bent or dropped valve as it is difficult to get the proper geometry to gain full effect of the ratio change without imparting side loads on the valve stem. Many a backyard hot-rodder, including myself, has tried this cheap-skate way of what should have been done to begin with - installing the proper cam.
Automakers the world over spending $250MM+ on a new engine design aren't going to favor this band-aid of mucking with rocker arm geometry to get desired lift and ramp profile; they'll do it right the first time with a proper cam grind. Further, the relatively flimsy rocker out there on pedestal waving in the wind speaks to the exact same mechanical bandwidth issues as the push rods themselves.
Further, the "mass issue" is per valve not per engine, as the principal detriment comes in the ability to cycle the valve at higher speeds, not the overall size or weight of the engine; more mass per valve + beefier valve springs + flimsy rocker + flimsy pushrod = lower mechanical bandwidth.
Lastly, there is no "argument" only "explanation." Simply put, it's not opinion that the OHC engine is inherently superior, it is objective engineering fact endorsed by the world's automakers for decades. Anecdotal backyard hot rodding is not a sufficient counter.
Quote from: GoCougs on June 18, 2009, 08:31:21 PM
Lastly, there is no "argument" only "explanation." Simply put, it's not opinion that the OHC engine is inherently superior, it is objective engineering fact endorsed by the world's automakers for decades. Anecdotal backyard hot rodding is not a sufficient counter.
That's a bunch of crap and you know it. What automakers use more often does not make something better or worse, it just tells you what they prefer to use. If OHC was so much better why hasn't GM switched over to it for their LS engines? Because they have found ways to achieve similar performance with OHV. End of story.
Quote from: hotrodalex on June 18, 2009, 09:05:24 PM
That's a bunch of crap and you know it. What automakers use more often does not make something better or worse, it just tells you what they prefer to use. If OHC was so much better why hasn't GM switched over to it for their LS engines? Because they have found ways to achieve similar performance with OHV. End of story.
Engineering principals are not "crap." Further, note that I stated "inherently" superior, and unlike most everyone else, I have stated why this is so, for a dozen pages.
If pushrod engines were so inherently "similar" where are all the push rod V6 and I4 GM engines? They have been replaced because there is so much more competition in the I4 and V6 market that push rod engines were outclassed long ago.
The LS can saunter on because there is so little competition for bread-n-butter V8s; primarily Ford, Dodge and to a much, much lesser extent Toyota and Nissan. But make no mistake about it, for every LS application there is an OHC competitor that is superior
It's not a bad or terrible engine; I've owned and worked on numerous push rod engines, but make no mistake about it, they are objectively inherently inferior. The world's automakers and basic engineering principals have had their say.
Quote from: GoCougs on June 18, 2009, 10:06:56 PM
Engineering principals are not "crap." Further, note that I stated "inherently" superior, and unlike most everyone else, I have stated why this is so, for a dozen pages.
If pushrod engines were so inherently "similar" where are all the push rod V6 and I4 GM engines? They have been replaced because there is so much more competition in the I4 and V6 market that push rod engines were outclassed long ago.
The LS can saunter on because there is so little competition for bread-n-butter V8s; primarily Ford, Dodge and to a much, much lesser extent Toyota and Nissan. But make no mistake about it, for every LS application there is an OHC competitor that is superior
It's not a bad or terrible engine; I've owned and worked on numerous push rod engines, but make no mistake about it, they are objectively inherently inferior. The world's automakers and basic engineering principals have had their say.
All the pushrod 4 and 6 cyl are dead because GM moved onto OHC designs. I think this was in part to
appear more modern and like the Japanese brands that were taking over in segments that used 4 and 6 cyl engines.
Quote from: hotrodalex on June 19, 2009, 10:54:51 AM
All the pushrod 4 and 6 cyl are dead because GM moved onto OHC designs. I think this was in part to appear more modern and like the Japanese brands that were taking over in segments that used 4 and 6 cyl engines.
Or it might have to do with the fact that GM's most powerful OHV V6 is the 3800 Supercharged, which is still underpowered compared to the latest DOHC mills. ;)
The E, N, K, 1, etc. VIN code motors, including the 3.1, 3.4, 3.8 and the even newest 3.5 and 3.9 aren't up to the task of keeping up in the HP war, not to mention the fact they are corse, awful sounding motors. This is why the High Feature 3.6 is gradually making its way into everything V6 powered.
Let's also put this in perspective, the OHC engine is a subset of OHV engine, not separate from it. The L-head/Flathead/valve-in-block engine IS a separate type of engine. So posting the flathead misses the point.
Second, in automotive engines, "mechanical bandwidth" is already a non-starter. We talk of extremely bleeding edge, 9000 rpm street engines in current Hondas, and yet 9000 rpm was easily built from pushrod engines with bigger valves in the '60s in streetable cars. Just because the companies controlled by bean counters, rather than enthusiasts, limited their use in street cars doens't mean that it was/is impossible or even improbable.
Quote from: hotrodalex on June 19, 2009, 10:54:51 AM
All the pushrod 4 and 6 cyl are dead because GM moved onto OHC designs. I think this was in part to appear more modern and like the Japanese brands that were taking over in segments that used 4 and 6 cyl engines.
Or like R-inge said, the push rod 4/6 cyl engines were dropped simply because they couldn't keep pace with the power, mileage and NVH requirements of competitors...
95%+ of new car buyers have no clue as to the valve train of their engine.
Quote from: ChrisV on June 19, 2009, 11:06:28 AM
Let's also put this in perspective, the OHC engine is a subset of OHV engine, not separate from it. The L-head/Flathead/valve-in-block engine IS a separate type of engine. So posting the flathead misses the point.
The flathead is simpler and more compact design than the push rod engine. It is also inherently inferior. (= The analogy fits.)
Quote
Second, in automotive engines, "mechanical bandwidth" is already a non-starter. We talk of extremely bleeding edge, 9000 rpm street engines in current Hondas, and yet 9000 rpm was easily built from pushrod engines with bigger valves in the '60s in streetable cars. Just because the companies controlled by bean counters, rather than enthusiasts, limited their use in street cars doens't mean that it was/is impossible or even improbable.
The issue with dynamic performance isn't whether it can be done; most everyone here in this thread knows that NASCAR engines turn 9,000+ rpm, and that many a semi-serious bracket racer at your local drag strip will have push rod engines hitting 9,000+ rpm. The issue is how
well it is done, or what caveats/drawbacks/contingencies are needed to make it happen.
A 9,000 rpm push rod engine will have horrific idle quality, have no vacuum at idle, be rougher than all get-out, and power will be useless below about 5,000 rpm. Further, you'll have to use solid lifters and mega stiff valve springs that will be murder on cam lobes (= won't last more than a few thousand miles).
The 9,000 rpm Honda however is the exact opposite; meaning it is both streetable and warrantable (whereas a 9,000 rpm push rod engine is not). Bean counters aren't stopping 9,000 rpm push rod engines finding their way into modern production cars, fundamental engineering principals are.
Quote from: GoCougs on June 19, 2009, 11:47:43 AM
The issue with dynamic performance isn't whether it can be done; most everyone here in this thread knows that NASCAR engines turn 9,000+ rpm, and that many a semi-serious bracket racer at your local drag strip will have push rod engines hitting 9,000+ rpm. The issue is how well it is done, or what caveats/drawbacks/contingencies are needed to make it happen.
A 9,000 rpm push rod engine will have horrific idle quality, have no vacuum at idle, be rougher than all get-out, and power will be useless below about 5,000 rpm. Further, you'll have to use solid lifters and mega stiff valve springs that will be murder on cam lobes (= won't last more than a few thousand miles).
The 9,000 rpm Honda however is the exact opposite; meaning it is both streetable and warrantable (whereas a 9,000 rpm push rod engine is not). Bean counters aren't stopping 9,000 rpm push rod engines finding their way into modern production cars, fundamental engineering principals are.
And a 9,000 rpm Honda engine has
so much low end power... :rolleyes:
Quote from: hotrodalex on June 19, 2009, 02:21:19 PM
And a 9,000 rpm Honda engine has so much low end power... :rolleyes:
At least it's useable. :rolleyes:
Complaining that a Honda engine doesn't have torque is older than the internet.
Quote from: thecarnut on June 19, 2009, 03:26:40 PM
At least it's useable. :rolleyes:
Complaining that a Honda engine doesn't have torque is older than the internet.
I'm just saying that argument is crap as almost any engine made to rev very high isn't going to make low end power.
And you can make a very nice high-revving pushrod engine. I plan on doing it for my next project (small British roadster or something and a 302 cu in high revver)
Quote from: hotrodalex on June 19, 2009, 02:21:19 PM
And a 9,000 rpm Honda engine has so much low end power... :rolleyes:
High revs doesn't mean you can't make low end power. My bike revs to 9500 RPM. Peak torque (and there's plenty of it for a motor that size) arrives at around 3300 RPM.
The 2.0L S2000 had something like 150-155 lb-ft of torque. Show me another naturally aspirated 2.0 that makes that kind of torque?
Quote from: MX793 on June 19, 2009, 04:02:48 PM
High revs doesn't mean you can't make low end power. My bike revs to 9500 RPM. Peak torque (and there's plenty of it for a motor that size) arrives at around 3300 RPM.
The 2.0L S2000 had something like 150-155 lb-ft of torque. Show me another naturally aspirated 2.0 that makes that kind of torque?
I never said it's impossible in any motor, I said a Honda engine (like the S2000) doesn't make that much on the low end, which it doesn't. It doesn't start making a lot it's power until 5-6k rpm and up.
Quote from: GoCougs on June 19, 2009, 11:47:43 AM
The flathead is simpler and more compact design than the push rod engine. It is also inherently inferior. (= The analogy fits.)
The issue with dynamic performance isn't whether it can be done; most everyone here in this thread knows that NASCAR engines turn 9,000+ rpm, and that many a semi-serious bracket racer at your local drag strip will have push rod engines hitting 9,000+ rpm. The issue is how well it is done, or what caveats/drawbacks/contingencies are needed to make it happen.
A 9,000 rpm push rod engine will have horrific idle quality, have no vacuum at idle, be rougher than all get-out, and power will be useless below about 5,000 rpm. Further, you'll have to use solid lifters and mega stiff valve springs that will be murder on cam lobes (= won't last more than a few thousand miles).
The 9,000 rpm Honda however is the exact opposite; meaning it is both streetable and warrantable (whereas a 9,000 rpm push rod engine is not). Bean counters aren't stopping 9,000 rpm push rod engines finding their way into modern production cars, fundamental engineering principals are.
Couple of things
Any single cam profile/timing motor will have shitty low end, OHV or OHC so that's out.
Second of all and more importantly revving to 9,000 RPM isn't at all necessary to make power. I drove the S2K and while it's cool to rev to 9K, it really had no kind of low end. I enjoyed my 7,500 RPM 2.2L Accord's motor more because of its midrange... something that is lost in pointless internet debates like this. I would trade peak power for a strong midrange any day of the week, and push rod motors have no problem producing that. 99.9% of motors, even performance ones, don't need to rev anywhere near 9K to be enjoyable.
You still have yet to solidly prove how OHC is so much better than OHV. I'm not saying the opposite; I'm just saying cars like the Corvette + Viper are no worse off because they don't "rev to 9K"
Quote from: sportyaccordy on June 19, 2009, 04:59:39 PM
Couple of things
Any single cam profile/timing motor will have shitty low end, OHV or OHC so that's out.
Second of all and more importantly revving to 9,000 RPM isn't at all necessary to make power. I drove the S2K and while it's cool to rev to 9K, it really had no kind of low end. I enjoyed my 7,500 RPM 2.2L Accord's motor more because of its midrange... something that is lost in pointless internet debates like this. I would trade peak power for a strong midrange any day of the week, and push rod motors have no problem producing that. 99.9% of motors, even performance ones, don't need to rev anywhere near 9K to be enjoyable.
You still have yet to solidly prove how OHC is so much better than OHV. I'm not saying the opposite; I'm just saying cars like the Corvette + Viper are no worse off because they don't "rev to 9K"
In everyday driving, low- and mid-range power is much more valuable than having tons of power at rpm levels that you will never reach.
I reach high RPM power in the Swift every day... or at least, I try to find it, but I can't.
Quote from: sportyaccordy on June 19, 2009, 04:59:39 PM
Couple of things
Any single cam profile/timing motor will have shitty low end, OHV or OHC so that's out.
Second of all and more importantly revving to 9,000 RPM isn't at all necessary to make power. I drove the S2K and while it's cool to rev to 9K, it really had no kind of low end. I enjoyed my 7,500 RPM 2.2L Accord's motor more because of its midrange... something that is lost in pointless internet debates like this. I would trade peak power for a strong midrange any day of the week, and push rod motors have no problem producing that. 99.9% of motors, even performance ones, don't need to rev anywhere near 9K to be enjoyable.
You still have yet to solidly prove how OHC is so much better than OHV. I'm not saying the opposite; I'm just saying cars like the Corvette + Viper are no worse off because they don't "rev to 9K"
No, not out.
I did not start the trip down the diversionary 9,000 rpm road.
There is only education.
i hit 9,000 rpms several times a day -shrug-
Quote from: r0tor on June 22, 2009, 06:25:43 AM
i hit 9,000 rpms several times a day -shrug-
You have no choice :ucku:
Seriously though, someone please explain how the C6 Vette would benefit from an OHC motor.
Likely not enough to warrant the $100MM+ needed to develop an all-new engine platform, but that doesn't not imply that the inherent inferiority does not exist.
I have to go catch a flight to Tokyo, so the next post may very well be from a Toyota plant (probably won't have the time actually)...
Quote from: sportyaccordy on June 22, 2009, 11:00:37 AM
You have no choice :ucku:
Seriously though, someone please explain how the C6 Vette would benefit from an OHC motor.
smoother running engine with more power and a flatter torque curve as well as a higher redline to allow for more aggressive gearing
Quote from: sportyaccordy on June 19, 2009, 04:59:39 PM
Couple of things
Any single cam profile/timing motor will have shitty low end, OHV or OHC so that's out.
Absolutely not true. A single profile cam can be optimized for low end torque or mid range torque. There will be a loss of high end, but the tradeoff exists and is found in millions of engines.
Quote from: r0tor on June 22, 2009, 11:20:28 AM
smoother running engine with more power and a flatter torque curve as well as a higher redline to allow for more aggressive gearing
:lol:
You state these as if they are problems with the current Vette. BTW, they're not.
Quote from: HEMI666 on June 22, 2009, 11:37:26 AM
:lol:
You state these as if they are problems with the current Vette. BTW, they're not.
its completely ignorant to say the engine has no room for improvement
Quote from: r0tor on June 22, 2009, 12:16:13 PM
its completely ignorant to say the engine has no room for improvement
It can be improved, but would switching to an OHC design provide enough improvement to justify the development costs? I doubt it.
Quote from: r0tor on June 22, 2009, 12:16:13 PM
its completely ignorant to say the engine has no room for improvement
All things can be improved.
Quote from: Onslaught on June 22, 2009, 12:20:24 PM
All things can be improved.
Especially mass produced things.
Quote from: SVT32V on June 22, 2009, 11:34:09 AM
Absolutely not true. A single profile cam can be optimized for low end torque or mid range torque. There will be a loss of high end, but the tradeoff exists and is found in millions of engines.
I meant for that to say a single cam profile motor making high rpm power.
And the C6 is fine. If they threw in some gay ass Northstar it would be weaker + more expensive. Just check out the XLR for proof.
Quote from: GoCougs on June 15, 2009, 07:52:29 PM
No, not pointless; it's been educational.
There's a reasons only two of the world's automakers use push rod valve trains in new engine designs and with that it's only one engine each. The arguments; weight, size, cost, economy, performance, et al., have similarly been waged, and decided, by engine design departments the world over. Push rod engines lost out, as has been explained ad naseum in this thread.
Actually, there is absolutely no evidence of this.
There is, however, much evidence to support that most people perceive OHC engines to be more "modern" than their pushrod counterparts. If we polled 1000 people and posed the question to them, "Which engine is more modern and advanced, OHC or Pushrod?" probably all or most polled would respond with OHC.
People generally prefer to actually know little, it takes too much work to find out the truth for themselves.
This is not meant to say you, or anyone else, is wrong or right. I am just pointing out that perception fuels almost everything marketed.
Quote from: hounddog on June 22, 2009, 08:34:35 PM
Actually, there is absolutely no evidence of this.
There is, however, much evidence to support that most people perceive OHC engines to be more "modern" than their pushrod counterparts. If we polled 1000 people and posed the question to them, "Which engine is more modern and advanced, OHC or Pushrod?" probably all or most polled would respond with OHC.
People generally prefer to actually know little, it takes too much work to find out the truth for themselves.
This is not meant to say you, or anyone else, is wrong or right. I am just pointing out that perception fuels almost everything marketed.
Don't question cougs, he has real world experience in numerous plants across america, took a class at MIT, and is basically the best businessman engineer out there.
Cougs/everyone in this thread knows engines about as much as I can write.
Quote from: Minpin on June 22, 2009, 08:39:53 PM
Don't question cougs, he has real world experience in numerous plants across america, took a class at MIT, and is basically the best businessman engineer out there.
Cougs/everyone in this thread knows engines about as much as I can write.
:lol: :lol: :lol:
Put down the coffee cup, and step away. :lol:
Honestly, I have not, nor do I have any intention of, reading most of the posts here. And, I am not doubting his knowledge or experience when it comes to engines and how/why they came to market. I have zero, personally. I have to rely on what I see and know from my own experience.
And, with that being the case, I just think that the OHC issue came to pass because people erroneously believe the engine is more advanced. As in, "All the Euro trash cars have them, they HAVE to be better."
Quote from: hotrodalex on June 22, 2009, 12:18:18 PM
It can be improved, but would switching to an OHC design provide enough improvement to justify the development costs? I doubt it.
whats the extra cost development and parts cost involved with needing to supercharge the engine to get 600 hp?
Quote from: sportyaccordy on June 22, 2009, 08:30:42 PM
I meant for that to say a single cam profile motor making high rpm power.
And the C6 is fine. If they threw in some gay ass Northstar it would be weaker + more expensive. Just check out the XLR for proof.
The northstar is an old design that was never that good to begin with. Using that as the consumate example of a good OHC engines is like using a T-ball player as an example of a Red Sox player.
Quote from: r0tor on June 23, 2009, 08:55:40 AM
whats the extra cost development and parts cost involved with needing to supercharge the engine to get 600 hp?
That's irrelevant, as you would not get 600 hp out of the OHC design.
Quote from: hotrodalex on June 23, 2009, 01:50:26 PM
That's irrelevant, as you would not get 600 hp out of the OHC design.
How much HP does the DOHC Porsche Carrera GT make? That's right, 600+. Naturally aspirated. 5.7L. A 6+ liter motor should certainly be able to generate 600 hp without forced induction given a valvetrain that allows for sufficient breathing.
Quote from: MX793 on June 23, 2009, 04:57:06 PM
How much HP does the DOHC Porsche Carrera GT make? That's right, 600+. Naturally aspirated. 5.7L. A 6+ liter motor should certainly be able to generate 600 hp without forced induction given a valvetrain that allows for sufficient breathing.
yet alone a 7.0L engine...
Quote from: MX793 on June 23, 2009, 04:57:06 PM
How much HP does the DOHC Porsche Carrera GT make? That's right, 600+. Naturally aspirated. 5.7L. A 6+ liter motor should certainly be able to generate 600 hp without forced induction given a valvetrain that allows for sufficient breathing.
Seeing as how they had trouble fitting the 4.6L DOHC Northstar in the Y car chassis, then I'd say the most power the corvette would have is however much you can get from 4.6L if they went to DOHC
Quote from: MX793 on June 23, 2009, 04:57:06 PM
How much HP does the DOHC Porsche Carrera GT make? That's right, 600+. Naturally aspirated. 5.7L. A 6+ liter motor should certainly be able to generate 600 hp without forced induction given a valvetrain that allows for sufficient breathing.
Who gives a shit about displacement?
You might as well pick any other arbitrary variable and bitch about that.
It's disgusting some engineers are considering displacement when it comes to efficiency. Plan and simple, the only things that matter in this debate at this point are gas mileage, power (and essentially the torque curve).
Efficiency is the power in divided by the power out. The Corvette does pretty well in both areas. I don't give a shit about displacement when it still gets respectable gas mileage for how much power it makes.
EDIT: That's a horrible fucking example too. You're going to compare a $50,000 sports car to one that costs over 10 times that much? Jeebus man.
Quote from: HotRodPilot on June 23, 2009, 05:46:09 PM
Seeing as how they had trouble fitting the 4.6L DOHC Northstar in the Y car chassis, then I'd say the most power the corvette would have is however much you can get from 4.6L if they went to DOHC
Who says the 4.6 Northstar is optimized for size? Keep in mind that that motor was designed for use in transverse, FWD applications so the emphasis was on making the block short in length, not necessarily low in height or narrow in width. Also, supposedly, that motor has enough room to be bored/stroked out to upwards of 5.4L.
Quote from: MrH on June 23, 2009, 05:57:30 PM
Who gives a shit about displacement?
You might as well pick any other arbitrary variable and bitch about that.
I wasn't bitching about displacement, I was simply indicating that it's not unheard of for naturally aspirated motors of roughly the same displacement as the SBC to generate 600+ hp. And displacement is a huge factor in how much power a motor can ultimately generate. Power is how quickly you can liberate heat from fuel, and since fuel has to be burned in a certain ratio with air, it comes down to how quickly the engine can pump air. That is purely a function of RPM and displacement (and volumetric efficiency).
Claiming a 2.0L motor can make 600+ hp without FI would raise a flag in anybody's mind that that's not possible. Why? Because power is a direct function of how much air the motor can move, and in order for a 2.0L motor to move enough air to make 600 hp, it's got to be revving at impossible RPMs, or acheiving impossible levels of VE. To say displacement doesn't come into the discussion is ridiculous.
QuoteIt's disgusting some engineers are considering displacement when it comes to efficiency. Plan and simple, the only things that matter in this debate at this point are gas mileage, power (and essentially the torque curve).
Efficiency is the power in divided by the power out. The Corvette does pretty well in both areas. I don't give a shit about displacement when it still gets respectable gas mileage for how much power it makes.
There are many forms of efficiency. There's thermal efficiency (heat in vs work out). There's fuel efficiency (which is related to thermal efficiency). There's volumetric efficiency. Specific output is more or less an expression of volumetric efficiency, just as BSFC is a measure of fuel and thermal efficiency.
QuoteEDIT: That's a horrible fucking example too. You're going to compare a $50,000 sports car to one that costs over 10 times that much? Jeebus man.
So the entire price difference between the Vette and the CGT is in the engine? Do you think that maybe the CGT costs significantly more because:
-It's handbuilt from unobtanium and in super limited numbers vs a mass produced car like the Corvette
-It utilizes practically nothing from other Porsches, thus not getting any benefit from economies of scale nor could costs be spread over multiple models
-The CGT was priced way above what it cost to make because it was super rare, highly saught after, and a Porsche
And there's a $50K Vette that makes 600 hp? Really? Sign me up. Last I checked, the ZR1 stickered for north of $100K. Yes, still well cheaper than a CGT, but also more common and using far more shared technology with other Vettes.
Quote from: MX793 on June 23, 2009, 06:23:48 PM
I wasn't bitching about displacement, I was simply indicating that it's not unheard of for naturally aspirated motors of roughly the same displacement as the SBC to generate 600+ hp. And displacement is a huge factor in how much power a motor can ultimately generate. Power is how quickly you can liberate heat from fuel, and since fuel has to be burned in a certain ratio with air, it comes down to how quickly the engine can pump air. That is purely a function of RPM and displacement (and volumetric efficiency).
Claiming a 2.0L motor can make 600+ hp without FI would raise a flag in anybody's mind that that's not possible. Why? Because power is a direct function of how much air the motor can move, and in order for a 2.0L motor to move enough air to make 600 hp, it's got to be revving at impossible RPMs, or acheiving impossible levels of VE. To say displacement doesn't come into the discussion is ridiculous.
There are many forms of efficiency. There's thermal efficiency (heat in vs work out). There's fuel efficiency (which is related to thermal efficiency). There's volumetric efficiency. Specific output is more or less an expression of volumetric efficiency, just as BSFC is a measure of fuel and thermal efficiency.
So the entire price difference between the Vette and the CGT is in the engine? Do you think that maybe the CGT costs significantly more because:
-It's handbuilt from unobtanium and in super limited numbers vs a mass produced car like the Corvette
-It utilizes practically nothing from other Porsches, thus not getting any benefit from economies of scale nor could costs be spread over multiple models
-The CGT was priced way above what it cost to make because it was super rare, highly saught after, and a Porsche
And there's a $50K Vette that makes 600 hp? Really? Sign me up. Last I checked, the ZR1 stickered for north of $100K. Yes, still well cheaper than a CGT, but also more common and using far more shared technology with other Vettes.
You can't compare the displacement of pushrods and OHC's, because generally, yes, pushrods are larger displacement for similar power outputs as OHC's. Does that make them less efficient though? No, it really doesn't. In the same sense, you could claim an OHC is less efficient than a pushrod because it gets worse gas mileage at a given displacement.
Displacement really doesn't come into this discussion. It shouldn't. Sure, there are other types of efficiencies. I'm well aware. But you're over complicating an issue that doesn't need to be that complicated. We've gone in circles talking about the size and weight of both designs. We can call it a mute point by now I'd think. All that matters is gas mileage and power output, both of which pushrods are competitive.
Because of this, it's just silly to say one design is flat out better than the other.
EDIT: And it's stupid to try and create a side argument as to how much the Carrera GT's motor costs in comparison to the ZR1's. It's still 6 times as much, and none of us have any fucking idea how the price of a Carrera GT actually breaks down. Again, another complicated, non-revelant issue.
Pushrods are competitive in both power delivery, and fuel economy. They're not automatically inferior. Period.
Quote from: MX793 on June 23, 2009, 04:57:06 PM
How much HP does the DOHC Porsche Carrera GT make? That's right, 600+. Naturally aspirated. 5.7L. A 6+ liter motor should certainly be able to generate 600 hp without forced induction given a valvetrain that allows for sufficient breathing.
That's irrelevant, as the Porsche costs 4x more.
When I said an OHC design isn't going to make 600+ hp without FI I meant one that costs the same as the OHV design. Any 6+ liter motor can generate 600 hp, but it's going to cost money, whether it's an OHC or OHV design.
Quote from: MrH on June 23, 2009, 06:39:12 PM
You can't compare the displacement of pushrods and OHC's, because generally, yes, pushrods are larger displacement for similar power outputs as OHC's. Does that make them less efficient though? No, it really doesn't. In the same sense, you could claim an OHC is less efficient than a pushrod because it gets worse gas mileage at a given displacement.
At the same power, an OHC generally won't get worse fuel economy than a pushrod. It takes a certain minimum fuel burn rate to generate X horsepower. All other efficiencies the same, it doesn't matter how big the engine is, one motor making 200 hp will consume just as much fuel to make that power as any other.
QuoteDisplacement really doesn't come into this discussion. It shouldn't. Sure, there are other types of efficiencies. I'm well aware. But you're over complicating an issue that doesn't need to be that complicated. We've gone in circles talking about the size and weight of both designs. We can call it a mute point by now I'd think. All that matters is gas mileage and power output, both of which pushrods are competitive.
The OHC's big advantage is flexibility, not necessarily specific output (although one kind of goes hand in hand with the other). The ability to easily phase exhaust and intake timing independantly and the relative ease by which variable valve lift can be implemented. This broadens the torque curve and improves BSFC over a wider range of RPMs (fatter torque curve and a broader sweet spot on the BSFC curve). The ability to eliminate the throttle plate by way of variable valve lift is another boost to efficiency. OHC motors have been using VVT/cam phasing for over 20 years and its been standard fare for quite some time (even run of the mill, inexpensive economy cars have been using VVT on at least the intakes for close to 10 years now). Pushrods have only just recently started to utilize cam phasing or any sort, and its effectiveness is limited because it's not straightforward, or inexpensive, to implement independant phasing of the intakes and exhaust. And although that hurdle of independantly phasing the intake and exhaust valves has been passed, there's only one pushrod motor with that capability on the market today (and it's expensive). I've still yet to see a pushrod that utilizes variable lift.
QuoteBecause of this, it's just silly to say one design is flat out better than the other.
I consider an engine design with more flexibility and greater power production potential to be a better design. That doesn't mean that I consider every OHC motor to be automatically superior to any and every pushrod.
QuoteEDIT: And it's stupid to try and create a side argument as to how much the Carrera GT's motor costs in comparison to the ZR1's. It's still 6 times as much, and none of us have any fucking idea how the price of a Carrera GT actually breaks down. Again, another complicated, non-revelant issue.
The Carrera GT retailed for 440K. That's hardly 6x as much. Consider also that Porsche only produced about 1250 of them in 2 years, and only about 600 of those found their way to America. Chevy's slated to produce around 2000 ZR-1s a year, the vast majority of which I expect to be sold in the US. By virtue of rarity (ignore the fact that the CGT utilized a CF monocoque and subframe vs the ZR1's undoubtedly less expensive aluminum chassis, or that the CGT's chassis design was created from a clean slate while the ZR1 started life as a regular Vette that was then upgraded, or that the CGT's motor was totally new from the ground up while the ZR1's started life as a run of the mill smallblock that can be found in several GM models), the CGT should command a significantly higher price.
QuotePushrods are competitive in both power delivery, and fuel economy. They're not automatically inferior. Period.
I'd argue that the design is inferior, even though a well executed example can certainly better some examples of OHC.
I know that if somebody handed me a bunch of development dollars to create a totally new-from-the-ground-up motor to be used in several pending vehicle applications (SUV, passenger car, luxury car and a performance car), I wouldn't be spending that money to design a new pushrod. Would you?
I'd also point out that fuel economy is not solely a function of the engine. It is very heavily dependant on gearing, aero and weight. Unless you're talking BSFC, fuel economy in an engine discussion is moot.
Quote from: MX793 on June 23, 2009, 07:52:22 PM
At the same power, an OHC generally won't get worse fuel economy than a pushrod. It takes a certain minimum fuel burn rate to generate X horsepower. All other efficiencies the same, it doesn't matter how big the engine is, one motor making 200 hp will consume just as much fuel to make that power as any other.
The OHC's big advantage is flexibility, not necessarily specific output (although one kind of goes hand in hand with the other). The ability to easily phase exhaust and intake timing independantly and the relative ease by which variable valve lift can be implemented. This broadens the torque curve and improves BSFC over a wider range of RPMs (fatter torque curve and a broader sweet spot on the BSFC curve). The ability to eliminate the throttle plate by way of variable valve lift is another boost to efficiency. OHC motors have been using VVT/cam phasing for over 20 years and its been standard fare for quite some time (even run of the mill, inexpensive economy cars have been using VVT on at least the intakes for close to 10 years now). Pushrods have only just recently started to utilize cam phasing or any sort, and its effectiveness is limited because it's not straightforward, or inexpensive, to implement independant phasing of the intakes and exhaust. And although that hurdle of independantly phasing the intake and exhaust valves has been passed, there's only one pushrod motor with that capability on the market today (and it's expensive). I've still yet to see a pushrod that utilizes variable lift.
OHC still don't make the same kind of torque at such low RPM's as pushrods do, in general. This, combined with some long ass gearing up top, and you can get great fuel economy. I will agree OHC is a more flexible platform, but it has its disadvantages too.
I consider an engine design with more flexibility and greater power production potential to be a better design. That doesn't mean that I consider every OHC motor to be automatically superior to any and every pushrod.
By greater power production potential, you mean that only in the context of more power potential for a given displacement. My answer to that immediately is, who cares what the displacement is again? This is all coming down to power and fuel consumption. You can just use a larger displacement OHV engine, gear it a little longer, and get comparable gas mileage.
The Carrera GT retailed for 440K. That's hardly 6x as much. Consider also that Porsche only produced about 1250 of them in 2 years, and only about 600 of those found their way to America. Chevy's slated to produce around 2000 ZR-1s a year, the vast majority of which I expect to be sold in the US. By virtue of rarity (ignore the fact that the CGT utilized a CF monocoque and subframe vs the ZR1's undoubtedly less expensive aluminum chassis, or that the CGT's chassis design was created from a clean slate while the ZR1 started life as a regular Vette that was then upgraded, or that the CGT's motor was totally new from the ground up while the ZR1's started life as a run of the mill smallblock that can be found in several GM models), the CGT should command a significantly higher price.
I thought the Carrera GT retailed for around $660,000? My fault. But again, you must have missed what I said earlier. It's stupid to try and argue how much R&D or manufacturring dollars went into either engine. We don't have a fucking clue. This whole argument is pointless.
I'd argue that the design is inferior, even though a well executed example can certainly better some examples of OHC.
I know that if somebody handed me a bunch of development dollars to create a totally new-from-the-ground-up motor to be used in several pending vehicle applications (SUV, passenger car, luxury car and a performance car), I wouldn't be spending that money to design a new pushrod. Would you?
No. It's also a personal preference. It's just frustrating to hear someone immediately claim one design is inferior to the other. I wouldn't say either is necessarily better
I'd also point out that fuel economy is not solely a function of the engine. It is very heavily dependant on gearing, aero and weight. Unless you're talking BSFC, fuel economy in an engine discussion is moot.
The fuel economy discussion isn't moot. It's one of the most important aspects of an engine to the consumers. It's dependent on gearing, aero, and weight, yes, but gearing is also dependent on the engine. Because pushrods make so much torque at such low RPM's, gearing can take advantage of that, and that is how pushrods tend to get relatively good gas mileage for the kind of power they output. To say that pushrods are more inefficient despite making similar power and consuming relatively the same amount of gas as an OHC is just inane.
Quote from: MX793 on June 23, 2009, 04:57:06 PM
How much HP does the DOHC Porsche Carrera GT make? That's right, 600+. Naturally aspirated. 5.7L. A 6+ liter motor should certainly be able to generate 600 hp without forced induction given a valvetrain that allows for sufficient breathing.
Crrrrrrra GT also has to rev to like 10K to do so.
Plus it has ITBs and huge ass air boxes that would never fit under the hood of a C6, even as a V8.
(http://www.carpages.co.uk/porsche/porsche_images/porsche_carrera_gt_engine_01_06_04.jpg)
Aftermarket outfits have been supercharging V8s forever. I'm sure whoever Chevy sourced the LS whatever is in the ZR1's blower from didn't have to do much research. Plus you don't even need to open up the block to make over 500WHP from an LSx motor.
http://img111.imageshack.us/i/dynochartwebki9.jpg/ <--565WHP 427, cams, I/H/E. Granted it probably idles like crap or w/e but its not impossible.
And OHV motors can have VVL + VVT. Well the idea has been patented anyway. I just don't think the need + opportunity has presented itself.
http://www.pattakon.com/vva/SideCam.htm
GF is complaining, it's bedtime. But I have more for tomorrow
This is the debate that never ends
Yes it goes on and on my friend
Some people started arguing not knowing what it was
and they'll continue arguing it forever just because
This is the debate that never ends...
Quote from: MrH on June 23, 2009, 08:17:20 PM
OHC still don't make the same kind of torque at such low RPM's as pushrods do, in general. This, combined with some long ass gearing up top, and you can get great fuel economy. I will agree OHC is a more flexible platform, but it has its disadvantages too.
Oh? Have you ever compared dynos for an LT5 and an LS6? The LT5 makes 90%+ of its peak torque from around 2200 rpm to 5800 RPM. It revved to 7 grand and if we assume the useable band starts at 1000 RPM, that's 90%+ of peak torque over 60% of the useable powerband. The LS6 didn't hit 90% of its torque peak until 3000 RPM, held 90% until about 6000 RPM, and only revved to 6500. That's about 54%. More torque lower in the band, and held longer. And that's without the benefit of any VVTL technology on the LT5 while the LS6 had more exotic materials and a solid 10 years worth of added development effort and money pumped into it. Imagine if you fattened that torque band up with newer valve control wizardry.
QuoteBy greater power production potential, you mean that only in the context of more power potential for a given displacement. My answer to that immediately is, who cares what the displacement is again? This is all coming down to power and fuel consumption. You can just use a larger displacement OHV engine, gear it a little longer, and get comparable gas mileage.
And the taller gearing will effectively negate the extra power by decreasing the power/speed ratio for each gear. Yeah, the engine makes more power, but you're sacrificing your average power to the road vs speed by stretching the gearing. Consider that a 220 hp Pontiac G6 with the 3.5 pushrod doesn't perform appreciably better than 4 cylinder counterparts like the Nissan Altima or Honda Accord, despite a hefty peak power advantage. Yeah, it's nice to brag that your car has 25-30% more peak power, but who gives a rats ass when it doesn't perform much, if any, better? Not to mention compromised in-gear responsiveness, or the tendancy for the gearbox (if automatic) to hunt gears or constantly lock/unlock the TC as soon as you come to the slightest incline.
QuoteThe fuel economy discussion isn't moot. It's one of the most important aspects of an engine to the consumers. It's dependent on gearing, aero, and weight, yes, but gearing is also dependent on the engine. Because pushrods make so much torque at such low RPM's, gearing can take advantage of that, and that is how pushrods tend to get relatively good gas mileage for the kind of power they output. To say that pushrods are more inefficient despite making similar power and consuming relatively the same amount of gas as an OHC is just inane.
There is nothing about a pushrod that makes it better at making low end grunt. And if you're making more low end power, you're burning more low end fuel. I've said it once and I'll say it again: If two cars are using the same amount of power to cruise along the road, assuming comparable BSFCs, they're going to be burning the same amount of fuel. GM can get mileage from their "big" pushrods that rivals smaller OHCs because they use the gearing to reduce the power outputs at the wheels at the common cruise speeds to the same levels as what the smaller OHCs are putting out. You can use the same tactic on a big, torquey OHC motor too. Case in point, the LT5 ZR-1 got the exact same fuel economy (actually, one MPG better on the highway) as the standard LT1 powered car, despite making gobs more power and torque.
I do enjoy reading this thread, and others like it.
Quote from: MrH on June 23, 2009, 05:57:30 PM
Who gives a shit about displacement?
You might as well pick any other arbitrary variable and bitch about that.
It's disgusting some engineers are considering displacement when it comes to efficiency. Plan and simple, the only things that matter in this debate at this point are gas mileage, power (and essentially the torque curve).
Efficiency is the power in divided by the power out. The Corvette does pretty well in both areas. I don't give a shit about displacement when it still gets respectable gas mileage for how much power it makes.
EDIT: That's a horrible fucking example too. You're going to compare a $50,000 sports car to one that costs over 10 times that much? Jeebus man.
Ooh, ouch - MrH has a ultra mega face-palm Carnot cycle fail...
Why are guys unhinged on the Carrera GT? Someone issued a throw-down on 600 hp ~N/A 6.0L, and it has been answered, but I'll help answer it further:
But what of the 911 GT3's 435 hp 3.8L at $110k, or even better yet, the 370's 330 hp 3.7L at $31k...
I am interested in what you OHC guys have against pushrods and vice-versa. I haven't really seen any black and white proof that one is far and away better than the other, so it seems misguided to be a fanboy either way. I could have overlooked something, but so far all I have seen is mindless bantering back and forth.
Quote from: GoCougs on June 23, 2009, 11:06:12 PM
Ooh, ouch - MrH has a ultra mega face-palm Carnot cycle fail...
For the purposes of this conversation, that's COMPLETELY irrelevant. At this point, when debating about which is better, you might as well consider an engine to just be a magical box.
Quote from: GoCougs on June 23, 2009, 11:11:17 PM
Why are guys unhinged on the Carrera GT? Someone issued a throw-down on 600 hp ~N/A 6.0L, and it has been answered, but I'll help answer it further:
But what of the 911 GT3's 435 hp 3.8L at $110k, or even better yet, the 370's 330 hp 3.7L at $31k...
Again, who gives a fuck about what the displacement is? Pushrods are making the same power, if not more, and getting similar gas mileage...
Quote from: Minpin on June 23, 2009, 11:13:46 PM
I am interested in what you OHC guys have against pushrods and vice-versa. I haven't really seen any black and white proof that one is far and away better than the other, so it seems misguided to be a fanboy either way. I could have overlooked something, but so far all I have seen is mindless bantering back and forth.
I don't even like pushrods much, I just hate when someone is arrogant enough to claim their opinion is fact, and then try to back it up with bullshit arguments.
Quote from: MrH on June 23, 2009, 11:24:30 PM
For the purposes of this conversation, that's COMPLETELY irrelevant. At this point, when debating about which is better, you might as well consider an engine to just be a magical box.
Actually, you're correct; I was intending to say "Otto" cycle.
To state that considering displacement relative to efficiency is "disgusting" makes me suspect that unlike virtually any power train engineer you haven't yet had thermodynamics.
The reason why displacement is relevant is pumping losses; more displacement = more pumping losses = lower efficiency.
Your fervor coupled with your wronginess astounds me, BTW.
Mr H and Cougs need to lay off the ad hominem attacks, they do nothing to help either of your arguments
I agree though that displacement considerations are somewhat meaningless... take two cars, similar weight, power, gearing, aerodynamics, one OHC one OHV, I really doubt there will be a huge difference in gas mileage if anyy
G6 220 HP V6 gets worse gas mileage than all its same yr counterparts... all with fancy CVTs and 6 spd auto trannys
But compared with (7-8yr old, but w/equal power) LIGHTER, older 4spd V6 similar power counterparts its just as efficient fuel wise. If GM got off their asses and gave the G6 a 6 spd auto I'm sure it would get similar #'s to newer cars
Its not the motor, it's GM's laziness
Quote from: MrH on June 23, 2009, 08:17:20 PM
The fuel economy discussion isn't moot. It's one of the most important aspects of an engine to the consumers. It's dependent on gearing, aero, and weight, yes, but gearing is also dependent on the engine. Because pushrods make so much torque at such low RPM's, gearing can take advantage of that, and that is how pushrods tend to get relatively good gas mileage for the kind of power they output. To say that pushrods are more inefficient despite making similar power and consuming relatively the same amount of gas as an OHC is just inane.
OK, I'm going to open up a huge fuggin can of rant on this one. The LS2 engine does NOT make incredible fuel mileage. I'm sorry, but it just does not. The Corvette, with its light weight, good aero, and a 6th gear that makes it an absolute dog when cruising makes good fuel mileage. Case in point, going on a 500 mile trip in a Trailblazer SS (with the LS2) we averaged a remarkable 14mpg while a similar V6 trailblazer made 21mpg and a V8 F150 made 16mpg on the trip. The GTO with an automatic tranny had a gas guzzler tax and the G8 with the automatic tranny and without the huge gearing of the manual tranny also doesn't make squat for fuel mileage.
Also, to ignore displacement mearly says whoever uses the biggest engine makes "the best" engine. Obviously then the Viper V10 is lightyears better then the small block chevy...
Quote from: GoCougs on June 24, 2009, 01:50:11 AM
Actually, you're correct; I was intending to say "Otto" cycle.
To state that considering displacement relative to efficiency is "disgusting" makes me suspect that unlike virtually any power train engineer you haven't yet had thermodynamics.
The reason why displacement is relevant is pumping losses; more displacement = more pumping losses = lower efficiency.
Your fervor coupled with your wronginess astounds me, BTW.
Why must you be so smug? Yes, I've taken thermo. You're overcomplicating a simple issue. All other things equal (weight, transmissions, aero, etc.), pushrods are making relatively similar power and gas mileage.
You can't dispute that. Displacement is irrelevant.
Quote from: MX793 on June 23, 2009, 09:23:15 PM
Oh? Have you ever compared dynos for an LT5 and an LS6? The LT5 makes 90%+ of its peak torque from around 2200 rpm to 5800 RPM. It revved to 7 grand and if we assume the useable band starts at 1000 RPM, that's 90%+ of peak torque over 60% of the useable powerband. The LS6 didn't hit 90% of its torque peak until 3000 RPM, held 90% until about 6000 RPM, and only revved to 6500. That's about 54%. More torque lower in the band, and held longer. And that's without the benefit of any VVTL technology on the LT5 while the LS6 had more exotic materials and a solid 10 years worth of added development effort and money pumped into it. Imagine if you fattened that torque band up with newer valve control wizardry.
And the taller gearing will effectively negate the extra power by decreasing the power/speed ratio for each gear. Yeah, the engine makes more power, but you're sacrificing your average power to the road vs speed by stretching the gearing. If it's only your top gear or two that's that tall, it doesn't really affect acceleration. It'll affect top gear acceleration clearly, but the Corvette makes so much torque at slower engine speeds, it's not all that bad pulling away in 6th. If adding taller gearing is an easy way to get better fuel economy then, why aren't most DOHC engines running a really tall final gear? Most don't have the torque to be able to sustain speed at that low of engine speeds.Consider that a 220 hp Pontiac G6 with the 3.5 pushrod doesn't perform appreciably better than 4 cylinder counterparts like the Nissan Altima or Honda Accord, despite a hefty peak power advantage. Yeah, it's nice to brag that your car has 25-30% more peak power, but who gives a rats ass when it doesn't perform much, if any, better? Not to mention compromised in-gear responsiveness, or the tendancy for the gearbox (if automatic) to hunt gears or constantly lock/unlock the TC as soon as you come to the slightest incline. That 4-speed is a piece of shit. I think we can agree on that. That's not the best example of a pushrod by any means either.
There is nothing about a pushrod that makes it better at making low end grunt. And if you're making more low end power, you're burning more low end fuel. I've said it once and I'll say it again: If two cars are using the same amount of power to cruise along the road, assuming comparable BSFCs, they're going to be burning the same amount of fuel. GM can get mileage from their "big" pushrods that rivals smaller OHCs because they use the gearing to reduce the power outputs at the wheels at the common cruise speeds to the same levels as what the smaller OHCs are putting out. You can use the same tactic on a big, torquey OHC motor too. Case in point, the LT5 ZR-1 got the exact same fuel economy (actually, one MPG better on the highway) as the standard LT1 powered car, despite making gobs more power and torque. Why do you think they killed the LT5 then? I'm honestly just wondering your opinion on it.
sorry, most economy cars in their top gear can pull on a corvette in 6th gear. Its not the incredible torque curve or anything else that lets them use a rediculous 6th gear - its mearly what they chose to do and what the buyers choose to deal with buying the car. I cruise around in 6th gear above 40mph fairly easily. My friend in his old Firebird wouldn't even think about going into 6th gear below 70mph because everytime he wanted to pass or had to go up a hill, his 500hp car was a slug... i would never want a useless gear taking up space in my tranny like that
Quote from: MrH on June 24, 2009, 05:54:44 AM
Why must you be so smug? Yes, I've taken thermo. You're overcomplicating a simple issue. All other things equal (weight, transmissions, aero, etc.), pushrods are making relatively similar power and gas mileage.
You can't dispute that. Displacement is irrelevant.
I'm not smug - you said that connecting displacement and efficiency was "disgusting" yet efficiency-robbing pumping losses is thermo 101...
Not making similar mileage and power; in fact it's essentially an incongruous comparison since there are so few push rod engines with which to compare.
And yes r0tor, you're 100% correct; there's nothing magic about the LS2; mpg or anything else. The Corvette is very light, shorter than a Civic, has a 1-4 skip shift, a 0.5:1 top gear, and slippery profile...
:popcorn:
Watching MrH pick a fight with Cougs for 14 pages is fun... :rolleyes:
Cougs claims he isn't smug? :lol:
Quote from: HEMI666 on June 24, 2009, 08:53:37 AM
Cougs claims he isn't smug? :lol:
We have a new comedian in the house!
Quote from: sportyaccordy on June 23, 2009, 08:39:09 PM
Aftermarket outfits have been supercharging V8s forever. I'm sure whoever Chevy sourced the LS whatever is in the ZR1's blower from didn't have to do much research. Plus you don't even need to open up the block to make over 500WHP from an LSx motor.
Eaton had to do research, but mostly just to make the blower a 4 lobe design. That increased efficiency enough for GM to use it over twin turbochargers. So Eaton did a bit of R&D and then GM put it on their engine (which wouldn't take much R&D, mostly just testing to make sure it's efficient, reliable, and is making enough power)
Quote from: r0tor on June 24, 2009, 05:53:40 AM
Also, to ignore displacement mearly says whoever uses the biggest engine makes "the best" engine. Obviously then the Viper V10 is lightyears better then the small block chevy...
Comprehension is lacking... every motor has its own merits; within the context of the Viper its motor makes sense. The Viper has a lot of faults but the motor is not one of them
An OEM will put 50x more research into a supercharger project then an aftermarket tuner because they do it the right way. All engine internals and drivetrain components get engineering reviews, the oil and engine cooling systems get redone, sometimes suspensions get retuned for different weight distributions, harnasses, fuse blocks, and sensors need to be specially made and placed, and then the entire ECU pretty much gets redone. Then they have to go through the entire round of reliability testing for the new package...
Quote from: r0tor on June 24, 2009, 10:00:31 AM
An OEM will put 50x more research into a supercharger project then an aftermarket tuner because they do it the right way. All engine internals and drivetrain components get engineering reviews, the oil and engine cooling systems get redone, sometimes suspensions get retuned for different weight distributions, harnasses, fuse blocks, and sensors need to be specially made and placed, and then the entire ECU pretty much gets redone. Then they have to go through the entire round of reliability testing for the new package...
Yes of course. But compared to a brand new engine project, it's not that much.
Quote from: r0tor on June 24, 2009, 10:00:31 AM
An OEM will put 50x more research into a supercharger project then an aftermarket tuner because they do it the right way. All engine internals and drivetrain components get engineering reviews, the oil and engine cooling systems get redone, sometimes suspensions get retuned for different weight distributions, harnasses, fuse blocks, and sensors need to be specially made and placed, and then the entire ECU pretty much gets redone. Then they have to go through the entire round of reliability testing for the new package...
Really not much more work than introducing a new Vette model though... sounds like a lot of work but they have engineers, fabricators etc who have been doing the stuff for years. They get together w/Eaton to work stuff out, no biggie. Not the first new motor they've ever built
The bottomline is there is a reason the ZR1 costs $30k more then a Z06... the supercharger is a big piece of that pie so no adding the supercharger is not a small deal or one that does not cost much money
Not loving the OHV is unamerican.
Case closed ;)
Quote from: r0tor on June 24, 2009, 10:00:31 AM
An OEM will put 50x more research into a supercharger project then an aftermarket tuner because they do it the right way. All engine internals and drivetrain components get engineering reviews, the oil and engine cooling systems get redone, sometimes suspensions get retuned for different weight distributions, harnasses, fuse blocks, and sensors need to be specially made and placed, and then the entire ECU pretty much gets redone. Then they have to go through the entire round of reliability testing for the new package...
Yep - designing (tuner) isn't engineering (automaker), and I think you're probably being generous at 50x (probably a lot higher)...
Quote from: r0tor on June 24, 2009, 06:08:18 AM
sorry, most economy cars in their top gear can pull on a corvette in 6th gear. Its not the incredible torque curve or anything else that lets them use a rediculous 6th gear - its mearly what they chose to do and what the buyers choose to deal with buying the car. I cruise around in 6th gear above 40mph fairly easily. My friend in his old Firebird wouldn't even think about going into 6th gear below 70mph because everytime he wanted to pass or had to go up a hill, his 500hp car was a slug... i would never want a useless gear taking up space in my tranny like that
Uhhh talk about throwing stones in glass houses.
If you think that Corvettes have bad top gear passing, then your RX8 has horrendous top gear passing times. A C6 Z51 has top gear passing times comparable with a GT-R or GT2 (as shown in my previous posts). This whole Corvettes will get burned by everything in Top Gear myth needs to stop. The real numbers tell a different story.
Here are the 30-50 and 50-70 passing times for your RX8.
http://www.caranddriver.com/content/download/2947/38823/version/1/file/0706_mazrx8_ts.pdf
30-50: 12.1
50-70: 10.9
And this is with gearing that forces the engine to spin over 3 grand at just 60mph.
Compare this to the C6 Z51.
http://www.caranddriver.com/content/download/125792/1704430/version/1/file/CD12CORVETTES_powertrain.pdf
30-50: 8.9
50-70: 8.3
Honestly look at the rest of the lineup from that RX8 comparo we'll see how not economy car the Corvette's top gear passing times are.
http://www.caranddriver.com/content/download/2870/38592/version/4/file/0706_fourkind_powertrain_ss.pdf
Note the Z51, even with it's super tall 6th gear, will out pass every car on that list (Shelby and 350Z) except the automatic TT(which isn't comparable because autos do it in the optimal gear). So most performance cars would be guilty of your "economy cars out pulling them in top gear" if it were true. A previous test showed that the C6 Z51 will also out pass the perfectly geared (redline limited top speed) GT2.
I'm willing to bet your buddy in the 500hp firebird will burn your car in 6th gear from 40mph as well. He refuses to go into 6th at lower speeds because his standards of speed are completely different from yours. His idea of lugging the engine is your idea of peak redline performance.
Quote from: HEMI666 on June 24, 2009, 08:53:37 AM
Cougs claims he isn't smug? :lol:
As with all things, there are black and white answers are at the heart of the explanation of why things they way they are (here, pushrods = inherently inferior = almost extinct); from inertia, to volumetric efficiency, to pumping losses, to mechanical stiffness, etc.
This entire thread is just one big dollop of some people ignoring these basic concepts, choosing to substitute conspiracy theories ("advertising"), backyard mechanicism, cherry-picked mag racerism, or just plain reticence to understand, frequently served up with a serving of attack and name calling.
After more than a dozen pages of this it becomes hard to maintain my usual bright and shiny self, but I will endeavor to hold the line.
Quote from: GoCougs on June 24, 2009, 02:52:24 PM
As with all things, there are black and white answers are at the heart of the explanation of why things they way they are (here, pushrods = inherently inferior = almost extinct); from inertia, to volumetric efficiency, to pumping losses, to mechanical stiffness, etc.
This entire thread is just one big dollop of some people ignoring these basic concepts, choosing to substitute conspiracy theories ("advertising"), backyard mechanicism, cherry-picked mag racerism, or just plain reticence to understand, frequently served up with a serving of attack and name calling.
After more than a dozen pages of this it becomes hard to maintain my usual bright and shiny self, but I will endeavor to hold the line.
It has nothing to do with that. You're arrogant and smug. Period. That is more definite then OHV vs. OHC. :lol: :lol: :lol:
Quote from: HEMI666 on June 24, 2009, 02:56:00 PM
It has nothing to do with that. You're arrogant and smug. Period. That is more definite then OHV vs. OHC. :lol: :lol: :lol:
Perhaps I wouldn't seem arrogant and smug if you guys would stop ignoring basic concepts...
I'm just wandering in here, so I've missed most of the thread, but can it basically be summarized as follows?
OHC Pros: Ability to rev higher (no mass of pushrods to contend with), easily accommodates 4 valve/cylinder designs plus VVT and variable lift means that more power can be generated due to the ability of the engine to flow more air through the engine at any given rpm.
Cons: Physical size of engine, especially the heads, due to the camshafts on top of the engine. Cost(?) due to the more complex design (longer timing chains, multiple cams, more complex cylinder head)
OHV Pros: Smaller, due to more compact arrangement of valvetrain, lower cost due to less complexity.
Cons: lack of ability to rev beyond a certain range for cost reasons and valvetrain, limited (compared to OHC) ability to make power from a given displacement and much simpler variable valve systems.
I'd mention fuel economy, but that's more a product of the vehicle, not the engine solely.
I guess there's no clear answer, unless we're comparing upon one aspect of engine design (ie physical size or whatnot) and it comes down to a cost vs. benefit question. I wonder how much it costs GM to manufacture an aluminum pushrod small-block truck engine vs. Toyota's cost to manufacture it's 5.7 DOHC.
Quote from: 565 on June 24, 2009, 02:37:45 PM
Uhhh talk about throwing stones in glass houses.
If you think that Corvettes have bad top gear passing, then your RX8 has horrendous top gear passing times. A C6 Z51 has top gear passing times comparable with a GT-R or GT2 (as shown in my previous posts). This whole Corvettes will get burned by everything in Top Gear myth needs to stop. The real numbers tell a different story.
Here are the 30-50 and 50-70 passing times for your RX8.
http://www.caranddriver.com/content/download/2947/38823/version/1/file/0706_mazrx8_ts.pdf
30-50: 12.1
50-70: 10.9
And this is with gearing that forces the engine to spin over 3 grand at just 60mph.
Compare this to the C6 Z51.
http://www.caranddriver.com/content/download/125792/1704430/version/1/file/CD12CORVETTES_powertrain.pdf
30-50: 8.9
50-70: 8.3
Honestly look at the rest of the lineup from that RX8 comparo we'll see how not economy car the Corvette's top gear passing times are.
.
so your argument is a car with 2x the power and 3-4x the displacement is faster? shocking
50-70 times... from c&d
WRX 7.6
MS3 6.7
Mini 6.3
GTI 4.2
cobalt ss 6.9
Quote from: r0tor on June 24, 2009, 04:06:13 PM
so your argument is a car with 2x the power and 3-4x the displacement is faster? shocking
No my argument is that your argument is wrong.
Quote from: 565 on June 24, 2009, 04:19:43 PM
No my argument is that your argument is wrong.
Well it looks like you're the one who's incorrect. My widdle WRX apparently will walk on a Corvette in top gear. :evildude:
Quote from: r0tor on June 24, 2009, 04:06:13 PM
so your argument is a car with 2x the power and 3-4x the displacement is faster? shocking
50-70 times... from c&d
WRX 7.6
MS3 6.7
Mini 6.3
GTI 4.2
cobalt ss 6.9
Quote from: HEMI666 on June 24, 2009, 02:56:00 PM
It has nothing to do with that. You're arrogant and smug. Period. That is more definite then OHV vs. OHC. :lol: :lol: :lol:
The fact that this argument has lasted this long primarily because people don't want to let Cougs be "right" is pretty telling of the whole motive of the discussion at this point. It's getting tired.
Quote from: R-inge on June 24, 2009, 04:36:47 PM
The fact that this argument has lasted this long primarily because people don't want to let Cougs be "right" is pretty telling of the whole motive of the discussion at this point. It's getting tired.
It'd be one thing if he actually was right to begin with. Many of us here know he's not.
Quote from: MrH on June 24, 2009, 04:42:43 PM
It'd be one thing if he actually was right to begin with. Many of us here know he's not.
If going to school and then hanging out in a factory in Germany for a few weeks tells you all there is to know, sign me up. The "debate" is pure vitriol at this point.
Like I said, there hasn't been any proof one way or the other. No one has proved that they are definitvelely right, and as such no one should claim that they are until it can be proven undeniably.
And Cougs you are smug, and you know it. You denying to be smug is all part of your smug acting. I would love to meet you in person, just to see how squirrely you really are. :praise:
Quote from: r0tor on June 24, 2009, 05:53:40 AM
The GTO with an automatic tranny had a gas guzzler tax a
Which is stupid because they can get about 26ish hwy. They're just goin by displacement and don't care what the car acutally did get.
Quote from: rohan on June 24, 2009, 05:00:38 PM
Which is stupid because they can get about 26ish hwy. They're just goin by displacement and don't care what the car acutally did get.
it tested at 14/19
I don't care what it tested- it doesn't get anywhere near that low on the hwy.
Quote from: MrH on June 24, 2009, 04:42:43 PM
It'd be one thing if he actually was right to begin with. Many of us here know he's not.
Then please, not only tell me I'm wrong, but specifically tell me the what/when/who/where/how/etc. Each time I've come back with basic, fundamental, objective subjects/facts/concepts, and I am mostly countered with anecdotes, mag racing, tangents, and otherwise get called names and ridiculed.
For example, you went so far as to state that it was "disgusting" to connect efficiency and displacement; this is simply not true; pumping losses, a function of displacement in the 4-cycle Otto engine, is a factor (and the reason why the diesel engine is inherently more efficient - very little pumping losses).
I was reading the last couple pages and (I'm sorry for plugging hounddog) but he's posted something that's pretty accurate a page or so back.
Quote from: GoCougs on June 24, 2009, 05:06:11 PM
Then please, not only tell me I'm wrong, but specifically tell me the what/when/who/where/how/etc. Each time I've come back with basic, fundamental, objective subjects/facts/concepts, and I am mostly countered with anecdotes, mag racing, tangents, and otherwise get called names and ridiculed.
For example, you went so far as to state that it was "disgusting" to connect efficiency and displacement; this is simply not true; pumping losses, a function of displacement in the 4-cycle Otto engine, is a factor (and the reason why the diesel engine is inherently more efficient - very little pumping losses).
Instead of him telling you why you are wrong, explain to me why you are right.
Quote from: rohan on June 24, 2009, 05:05:11 PM
I don't care what it tested- it doesn't get anywhere near that low on the hwy.
i reject your reality and substitute my own
Quote from: r0tor on June 24, 2009, 05:12:29 PM
i reject your reality and substitute my own
:lol:
The 545i is only supposed to get 25 on the highway but I can prove that mine gets as much as 30ish. :huh:
I don't have the GTO anymore so I can't prove shit about shit about it.
Quote from: Minpin on June 24, 2009, 05:10:27 PM
Instead of him telling you why you are wrong, explain to me why you are right.
That's backwards. The burden lies on the challenger to prove why a statement is false.
Quote from: rohan on June 24, 2009, 05:15:02 PM
:lol:
The 545i is only supposed to get 25 on the highway but I can prove that mine gets as much as 30ish. :huh:
I don't have the GTO anymore so I can't prove shit about shit about it.
The EPA's highway test isn't just cruising at a steady 70 mph. It involves some speed fluctuation between 45 and 65 mph. It's more akin to driving on a country back-road type highway with the odd reduced speed zone rather than an interstate type highway.
Quote from: R-inge on June 24, 2009, 04:45:45 PM
If going to school and then hanging out in a factory in Germany for a few weeks tells you all there is to know, sign me up. The "debate" is pure vitriol at this point.
All of this started when he started belittling me, telling me I know nothing. If he would have just answered what I brought up originally, none of this would have happened.
But yes, school and experience in the industry does help.
Quote from: MX793 on June 24, 2009, 05:22:45 PM
The EPA's highway test isn't just cruising at a steady 70 mph. It involves some speed fluctuation between 45 and 65 mph. It's more akin to driving on a country back-road type highway with the odd reduced speed zone rather than an interstate type highway.
Then they're doing it wrong. :lol:
Seriously I didn't know they did it like that- how can they call it "highway" then?
Quote from: GoCougs on June 24, 2009, 05:06:11 PM
Then please, not only tell me I'm wrong, but specifically tell me the what/when/who/where/how/etc. Each time I've come back with basic, fundamental, objective subjects/facts/concepts, and I am mostly countered with anecdotes, mag racing, tangents, and otherwise get called names and ridiculed.
For example, you went so far as to state that it was "disgusting" to connect efficiency and displacement; this is simply not true; pumping losses, a function of displacement in the 4-cycle Otto engine, is a factor (and the reason why the diesel engine is inherently more efficient - very little pumping losses).
I have, countless times.
You never answered what made parallel processing anymore cost effective besides reducing inventory between stages. You never answered why displacement is relevant at all to the discussion at hand. You never explained why displacement should be considered over any other arbitrary and pointless measurement when simply discussing power delivery and gas mileage.
Instead, you just keep trying to belittle everyone, and try to break off into side arguments in an attempt to overcomplicate the issue and hope everyone that disagrees with you will drop out of the argument. Most points you bring up has little to nothing to do with the topic at hand.
It's pointless to rebuttal your posts when you never actually answer back without being smug and just beat around the bush the whole time.
Quote from: MrH on June 24, 2009, 05:24:12 PM
All of this started when he started belittling me, telling me I know nothing. If he would have just answered what I brought up originally, none of this would have happened.
But yes, school and experience in the industry does help.
See, I don't even understand how what he said to you was belittling. You apparently took it personally and since then have been plowing ahead on a crusade to prove him wrong, with constant baiting, name-calling, and very little actual information.
Since then it's just been like an episode of Coyote vs Roadrunner, and you're the one who keeps auguring yourself into mountainsides with cheap Acme rockets, as far as I can tell.
Quote from: R-inge on June 24, 2009, 05:30:18 PM
See, I don't even understand how what he said to you was belittling. You apparently took it personally and since then have been plowing ahead on a crusade to prove him wrong, with constant baiting, name-calling, and very little actual information.
Since then it's just been like an episode of Coyote vs Roadrunner, and you're the one who keeps auguring yourself into mountainsides with cheap Acme rockets, as far as I can tell.
He just straight up said I was wrong, and quoted a book he had to read for class, which was a questionable source. When he just blatantly says I'm wrong and talks down to me, I consider that belittling. It wouldn't be bad if he actually would back up his posts half the time, but he doesn't.
That's the thing. Far as you can tell. You've said multiple times in this thread you don't know who is right. If you don't know, how can you really weigh in on who's right or wrong?
Just because I'm not as well spoken as Cougs doesn't mean I'm necessarily wrong. I've constantly brought up simple arguments that he just avoids.
Quote from: R-inge on June 24, 2009, 05:20:21 PM
That's backwards. The burden lies on the challenger to prove why a statement is false.
When it is an open debate you have to argue your side as well. There is no set challenger in this case because no one has proven themselves right, or won. ;)
Keep in mind I am neutral, I just want some facts and not the bullshit thats been going on.
Quote from: GoCougs on June 24, 2009, 05:06:11 PM
Then please, not only tell me I'm wrong, but specifically tell me the what/when/who/where/how/etc. Each time I've come back with basic, fundamental, objective subjects/facts/concepts, and I am mostly countered with anecdotes, mag racing, tangents, and otherwise get called names and ridiculed.
For example, you went so far as to state that it was "disgusting" to connect efficiency and displacement; this is simply not true; pumping losses, a function of displacement in the 4-cycle Otto engine, is a factor (and the reason why the diesel engine is inherently more efficient - very little pumping losses).
Ur whole schpiel is 'pushrods = inferior'
How is that fundamentally sound
If it was that basic + easy to explain u would have done so. Instead u posted ur resume in the hopes that that would help validate the opinions uve passed on as fact (pushrods = ALWAYS inferior)
Fact is any good engineer will tell you that deeming one technology over the other based on single metrics like HP/L or sales #'s is dumb as hell and is no way to look at things... every application has to be looked at individually
WOW! This thread won't die! :popcorn:
I think the viability of pushrods depends on application configuration
In the case of a longitudinal V8 in a small engine bay, a pushrod engine can get the job done pretty good
When a car is mid engine and you can get all the cams you want over the engine, then that's probably the way to go
Look at the 370Z vs. and old F-Body. In the Z, that engine is crammed and barely fits under the hood, then take a look under the low hood of the F-bodys and there seems more vertical space
Quote from: R-inge on June 24, 2009, 04:35:04 PM
Well it looks like you're the one who's incorrect. My widdle WRX apparently will walk on a Corvette in top gear. :evildude:
You miss the point. Your WRX will also walk a 911 GT2 in top gear. Most of the cars on Rotor's list will also walk a Nissan GT-R from the same speed. In fact if you look at the VW's 50-70 time, you'll see it will out pass both a 599GTB and a Aston Martin DBS from 50-70mph.
http://www.caranddriver.com/content/download/114713/1557240/version/1/file/Two-Car+Libido+Enhancer+-+Powertrain.pdf
Now would you say both those cars (DBS 599 GTB), the GT2 and the GT-R all have useless economy top gears? They clearly don't as they all have top gears perfectly calculated to run out with the cars top speed (redline limited top speed).
Rotor's reasoning is flawed because he posted a bunch of pocket rockets and tried to pass them off as true economy cars (how could your WRX be a true economy car when my z06 gets better economy?). None of those cars are geared to hit close to 200 mph like the GT2 or 599 or Corvettes, so their top gears are much shorter than a car that is geared to hit 200mph.
You can't make the claim that the Corvette is useless in top gear without making the claim that all those similarly accelerating supercars are useless in top gear.
Oh to further make this live for you guys...
GTI 50-70mph: 4.2 seconds
Carrera GT 50-70mph: 4.8 seconds
http://www.caranddriver.com/content/download/114713/1557240/version/1/file/Two-Car+Libido+Enhancer+-+Powertrain.pdf
Man by Rotor's standards because the mightly Carrera GT with it's superior OHC engine couldn't out pass an economy car like a plain VW, it must be a gutless piece of shit on the highway with a useless top gear (for economy purposes, no less).
Wow I completely, without a doubt, agree with Minpin for what may be the first time.
Stop claiming you are right when you have done nothing to prove it except throw out useless facts that half the time are twisted to fit your argument. Prove to me that the Corvette would perform better, have better fuel economy, or be cheaper with an OHC engine. If you cannot do this, then stop this silly thread and admit that neither engine is necessarily better.
Quote from: Minpin on June 23, 2009, 11:13:46 PM
I am interested in what you OHC guys have against pushrods and vice-versa. I haven't really seen any black and white proof that one is far and away better than the other, so it seems misguided to be a fanboy either way. I could have overlooked something, but so far all I have seen is mindless bantering back and forth.
Per the OHV supporters, because the OHVs used in street cars can offer a comparable combination of power and fuel economy to many OHCs used in street cars, they aren't an inferior design.
Let me respin this argument. I think we'd all accept that OHV > Flathead. But a flathead Briggs and Stratton lawnmower motor will do a fine job of cutting your grass. It does the job every bit as well as an OHV mower engine from Honda. Does that really mean that OHV isn't a superior engine design to a flathead? I mean, if they both can power a lawnmower just as well, how can one be inferior?
Quote from: Minpin on June 24, 2009, 05:50:50 PM
When it is an open debate you have to argue your side as well. There is no set challenger in this case because no one has proven themselves right, or won. ;)
Keep in mind I am neutral, I just want some facts and not the bullshit thats been going on.
Well, in that case I agree.
I am just tired of the infighting here lately, time to present arguments, accept others' perspectives and just move on. Taking offense at everything someone types is irritating, and it has distracted this thread from some otherwise very solid contributions from MX793, Hotrodalex, r0tor, and 565.
Quote from: gotta-qik-z28 on June 24, 2009, 06:00:28 PM
WOW! This thread won't die! :popcorn:
Yes I am doing everything to make sure this thread lives up to its title.
Quote from: MX793 on June 24, 2009, 09:21:34 PM
Per the OHV supporters, because the OHVs used in street cars can offer a comparable combination of power and fuel economy to many OHCs used in street cars, they aren't an inferior design.
Let me respin this argument. I think we'd all accept that OHV > Flathead. But a flathead Briggs and Stratton lawnmower motor will do a fine job of cutting your grass. It does the job every bit as well as an OHV mower engine from Honda. Does that really mean that OHV isn't a superior engine design to a flathead? I mean, if they both can power a lawnmower just as well, how can one be inferior?
It's hard to quantify lawnmower engines. I guess if you could get some sort of gas mileage number for both (feet of grass cut/gallon), you could compare them. If those were both equal, and cut grass equally well, then no, I wouldn't consider it an inferior design. Btw, did you see my response?
Not trying to ask a rhetorical question and trap you in any way, I'm just wondering what your thoughts are on why GM killed the LT5.
Quote from: MrH on June 25, 2009, 01:45:50 AM
It's hard to quantify lawnmower engines. I guess if you could get some sort of gas mileage number for both (feet of grass cut/gallon), you could compare them. If those were both equal, and cut grass equally well, then no, I wouldn't consider it an inferior design. Btw, did you see my response?
Not trying to ask a rhetorical question and trap you in any way, I'm just wondering what your thoughts are on why GM killed the LT5.
In an application like a lawnmower it would be quantified in something like Hours per Gallon or Hours per Half Gallon have very little fuel capacity since they. MPG is really only used in cars, because that is the most relevant and most relatable figure. Most boats quantify in GPM or gallons per mile or GPH or gallons per hour. A lot of smaller planes like cessna's use GPH as well.
Quote from: R-inge on June 24, 2009, 09:33:17 PM
Well, in that case I agree.
I am just tired of the infighting here lately, time to present arguments, accept others' perspectives and just move on. Taking offense at everything someone types is irritating, and it has distracted this thread from some otherwise very solid contributions from MX793, Hotrodalex, r0tor, and 565.
I have presented my argument countless times. Numerous examples have been provided to show that a pushrod is neither larger or heavier than a OHC design. Examples have also been provided to show that top gear acceleration isn't any worse than many high performing OHC engines. Power and fuel economy numbers are comparable to OHC engines.
It's pointless to bring displacement of volumetric efficiency into this. It's over complicating a simple issue. If size, weight, power delivery, and gas mileage are all relatively comparable, how is it so definitively inferior?
Quote from: Minpin on June 25, 2009, 01:53:17 AM
In an application like a lawnmower it would be quantified in something like Hours per Gallon or Hours per Half Gallon have very little fuel capacity since they. MPG is really only used in cars, because that is the most relevant and most relatable figure. Most boats quantify in GPM or gallons per mile or GPH or gallons per hour. A lot of smaller planes like cessna's use GPH as well.
Fair enough. If there's just some way to quantify gas consumption, and they are comparable and cut grass as well as each other, then no, I wouldn't say one design is inferior to another in lawnmowers.
Quote from: MrH on June 25, 2009, 01:45:50 AM
It's hard to quantify lawnmower engines. I guess if you could get some sort of gas mileage number for both (feet of grass cut/gallon), you could compare them. If those were both equal, and cut grass equally well, then no, I wouldn't consider it an inferior design. Btw, did you see my response?
Not trying to ask a rhetorical question and trap you in any way, I'm just wondering what your thoughts are on why GM killed the LT5.
The LT5, for its time, was somewhat exotic. It was all aluminum, vs the iron block LT1. It wasn't even built by GM, they contracted out the work to Mercury Marine (who hand built each motor). It didn't really share much, if anything, with the SBC engine line other than bore spacing. Bore was smaller and stroke was longer, which raised the deck height. It was also only used in one limited production halo car, whereas the SBC line was used in a number of different vehicle lines in various displacements and states of tune. This all made it a more expensive motor than the pushrod SBC. I'm sure if GM started making a more mass-produced version, perhaps with an iron block, and used it across the board like they do the pushrod SBC, they could have brought the costs down. Why didn't they pursue this? I don't know, I'm not an insider into the company's thinking.
Quote from: 565 on June 24, 2009, 07:23:41 PM
Oh to further make this live for you guys...
GTI 50-70mph: 4.2 seconds
Carrera GT 50-70mph: 4.8 seconds
oddly enough the Carrera GT is a 200mph car, has overhead cams, a V10, and its lighter then the LS7..... and faster.....
Quote from: r0tor on June 25, 2009, 05:48:44 AM
oddly enough the Carrera GT is a 200mph car, has overhead cams, a V10, and its lighter then the LS7..... and faster.....
And yet it still gets pulled by a lowly VW econobox in passing times, and thus is automatically crap, with a crappy useless top gear by your definition.
it at least beats R-inge's lowly WRX...
...actually i wonder if they had the GTI in manual or automatic mode with the DSG...
Quote from: MX793 on June 24, 2009, 09:21:34 PM
Let me respin this argument. I think we'd all accept that OHV > Flathead. But a flathead Briggs and Stratton lawnmower motor will do a fine job of cutting your grass. It does the job every bit as well as an OHV mower engine from Honda. Does that really mean that OHV isn't a superior engine design to a flathead? I mean, if they both can power a lawnmower just as well, how can one be inferior?
The OHC engine is not superior in that application. Just like the Corvette vs others. The Corvette (with pushrods) performs equally well as the other cars with OHC engines. So neither is inferior, in those applications.
I can agree that modern 4 cyl and 6 cyl OHV engines are not up to standards set by modern OHC engines. Sadly I'm not sure if it's due to the design or GM's crap engineering. If GM had been a strong company producing strong, solid, quality products the past 20 years then we would know, but that wasn't the case. The cars that used the 4-6 cyl pushrod engines weren't so good themselves, so I doubt they put much effort into the engine either.
Quote from: MrH on June 25, 2009, 01:53:51 AM
I have presented my argument countless times. Numerous examples have been provided to show that a pushrod is neither larger or heavier than a OHC design. Examples have also been provided to show that top gear acceleration isn't any worse than many high performing OHC engines. Power and fuel economy numbers are comparable to OHC engines.
It's pointless to bring displacement of volumetric efficiency into this. It's over complicating a simple issue. If size, weight, power delivery, and gas mileage are all relatively comparable, how is it so definitively inferior?
Because by oversimplifying things in order to make your perspective seem best you are missing some factors such as vehicle gearing, aerodynamics, etc. The fact is that the engine is not the final factor in a vehicle's fuel economy, so if we're having a debate about which engine design is better, you have to debate the engine alone, not the vehicles it's installed in. Because at that point you should then factor into your argument why it is that the Corvette gets good EPA fuel economy, or why the Carrera gets less. It is at that point that the argument gets muddied and ultimately it's more an argument about which package is better.
That said, packaging is still a relevant argument I think, but again if the debate is about best engine it should be about which design promotes the most efficient way to get the most power out of the same displacement. That, to me, is the only real way to compare things apples to apples. You may disagree, but getting off on some tangent for 14 pages about manufacturing, a topic that very few of us are familiar with let alone can see the relevance thereof, just distracts from that.
So tell me, cc for cc, which engine type is most efficient?
Quote from: r0tor on June 25, 2009, 05:48:44 AM
oddly enough the Carrera GT is a 200mph car, has overhead cams, a V10, and its lighter then the LS7..... and faster.....
....And 4x more expensive than the ZR1, so it better be faster and can afford to use exotic materials to make it lighter.
Who cares about the car? How about the engine?
Quote from: R-inge on June 25, 2009, 09:33:43 AM
Because by oversimplifying things in order to make your perspective seem best you are missing some factors such as vehicle gearing, aerodynamics, etc. The fact is that the engine is not the final factor in a vehicle's fuel economy, so if we're having a debate about which engine design is better, you have to debate the engine alone, not the vehicles it's installed in. Because at that point you should then factor into your argument why it is that the Corvette gets good EPA fuel economy, or why the Carrera gets less. It is at that point that the argument gets muddied and ultimately it's more an argument about which package is better.
That said, packaging is still a relevant argument I think, but again if the debate is about best engine it should be about which design promotes the most efficient way to get the most power out of the same displacement. That, to me, is the only real way to compare things apples to apples. You may disagree, but getting off on some tangent for 14 pages about manufacturing, a topic that very few of us are familiar with let alone can see the relevance thereof, just distracts from that.
So tell me, cc for cc, which engine type is most efficient?
What don't you get about my argument? You can't compare cc for cc, because there's no disadvantage to having more displacement in a pushrod when comparing to an OHC. You clearly don't understand my side of the argument. What downside is there to using more displacement if it still gets respectable gas mileage and comparable power?
That only thing measurable at this point is individual car economy, and 565 has already shown that top gear acceleration in the Corvette isn't any worse than a lot of exotics, so it's not strictly gearing. You think it's so slippery, or the transmission is that efficient, to account for the gas mileage?
Quote from: MrH on June 25, 2009, 09:46:02 AM
You can't compare cc for cc, because there's no disadvantage to having more displacement in a pushrod when comparing to an OHC.
you make zero sense
Quote from: R-inge on June 25, 2009, 09:36:18 AM
Who cares about the car? How about the engine?
I'm talking about the engine. We don't have the costs of the two engines, but if the whole car costs 4x more I'm sure they put more money into the engine.
Quote from: r0tor on June 25, 2009, 09:47:54 AM
you make zero sense
If I can have a 302 smallblock in my car and swap it out for 427 smallblock (like the LS7) and have it fit in the exact same place, what disadvantage is there?
Quote from: r0tor on June 25, 2009, 09:47:54 AM
you make zero sense
How does that not make sense? If a larger displacement pushrod can be competitive in every single category as a smaller displacement OHC engine, who gives a fuck what the displacement is? Usually more displacement would mean worst gas mileage, but miraculously, they don't get horrible gas mileage. Imagine that.
Quote from: MrH on June 25, 2009, 09:46:02 AM
What don't you get about my argument? You can't compare cc for cc, because there's no disadvantage to having more displacement in a pushrod when comparing to an OHC. You clearly don't understand my side of the argument. What downside is there to using more displacement if it still gets respectable gas mileage and comparable power?
That only thing measurable at this point is individual car economy, and 565 has already shown that top gear acceleration in the Corvette isn't any worse than a lot of exotics, so it's not strictly gearing. You think it's so slippery, or the transmission is that efficient, to account for the gas mileage?
You don't see this to be the case? Category 5 WTF man. How could gearing and aero and vehicle weight NOT have an impact on fuel economy, let alone myriad other factors such as the size and flow rate of each cylinder's valves, cam profiles, size of the throttle body, etc?
Here's a case in point. Yamaha FZ6 vs FZ6R. The FZ6 makes ~96hp with 41mm throttle bodies and high lift cams and gets an EPA 40mpg city. The FZ6R weighs 10lbs more, makes ~70hp with 37mm throttle bodies and low lift cams and gets an EPA 43MPG city. Both have roughly identical rear tire diameter and final drive ratios.
So there you go... pretty much identical chassis so you can see an actual comparison of what the engines are capable of without having to deal with the vehicle getting in the way.
So again, can you come up with something here or do you just want to keep ignoring some glaring deficiencies in your logic?
Quote from: MrH on June 25, 2009, 09:50:31 AM
How does that not make sense? If a larger displacement pushrod can be competitive in every single category as a smaller displacement OHC engine, who gives a fuck what the displacement is? Usually more displacement would mean worst gas mileage, but miraculously, they don't get horrible gas mileage. Imagine that.
Yeah because the displacement isn't the final factor. See throttle body sizes and cam profile argument in above post.
Quote from: R-inge on June 25, 2009, 10:32:54 AM
You don't see this to be the case? Category 5 WTF man. How could gearing and aero and vehicle weight NOT have an impact on fuel economy, let alone myriad other factors such as the size and flow rate of each cylinder's valves, cam profiles, size of the throttle body, etc?
Here's a case in point. Yamaha FZ6 vs FZ6R. The FZ6 makes ~96hp with 41mm throttle bodies and high lift cams and gets an EPA 40mpg city. The FZ6R weighs 10lbs more, makes ~70hp with 37mm throttle bodies and low lift cams and gets an EPA 43MPG city. Both have roughly identical rear tire diameter and final drive ratios.
So there you go... pretty much identical chassis so you can see an actual comparison of what the engines are capable of without having to deal with the vehicle getting in the way.
So again, can you come up with something here or do you just want to keep ignoring some glaring deficiencies in your logic?
We're comparing the gas mileage of the corvette to cars with similar top end acceleration, so it's not simply gearing, the cd of the corvette isn't mind blowingly lower than other cars. I don't know what you think is giving it such an advantage that this horribly inefficient engine can get respectable gas mileage.
Quote from: MrH on June 25, 2009, 10:44:37 AM
We're comparing the gas mileage of the corvette to cars with similar top end acceleration, so it's not simply gearing, the cd of the corvette isn't mind blowingly lower than other cars. I don't know what you think is giving it such an advantage that this horribly inefficient engine can get respectable gas mileage.
Yes, it can get respectable gas mileage in certain vehicles. That's not the point.
Also, to clarify what I was trying to illustrate, it is that here we have two roughly identical platforms yet there is a significant difference in power and fuel economy within what is pretty much the same engine (2 gen old R6) and same CC for that matter. So factor in the varying flow rates of a 2 valve OHV versus a 4 valve OHC and the varying cam profiles, etc and it becomes nearly impossible to even nail down the engine efficiency aspect. Add to that the vehicle weight, aero and gearing and you have even more variables to deal with.
Maybe I'm talking myself in a circle here... :lol:
Either way I disagree with your logic.
Quote from: R-inge on June 25, 2009, 10:33:42 AM
Yeah because the displacement isn't the final factor. See throttle body sizes and cam profile argument in above post.
So that throws your cc for cc most efficient question out the window. Mr H's stance makes perfect sense. You as an auto tech should know as well as anyone the differences valvetrain design make in overall engine size.
For the sake of the discussion engines are black boxes... main concerns are how big is the box? How much does it cost to make? How hard/expensive is it to service/maintain/replace? What kind of power does it make against its competitors? How good is it on OVERALL fuel consumption- not fuel consumption per liter of displacement (who freaking cares really? For example the EJ20T makes 220 or w/e HP, but it has a turbo system that adds mass + size + complexity... S2K makes 240HP but that head + cam + the level of engineering needed to make that kind of power = $$$$ + big ass head + not that great gas mileage)..
You have to look at the whole picture... when you start looking at details that are meaningless outside of the context of engine operation the discussion goes to shit.
Quote from: sportyaccordy on June 25, 2009, 10:51:03 AM
So that throws your cc for cc most efficient question out the window. Mr H's stance makes perfect sense. You as an auto tech should know as well as anyone the differences valvetrain design make in overall engine size.
For the sake of the discussion engines are black boxes... main concerns are how big is the box? How much does it cost to make? How hard/expensive is it to service/maintain/replace? What kind of power does it make against its competitors? How good is it on OVERALL fuel consumption- not fuel consumption per liter of displacement (who freaking cares really? For example the EJ20T makes 220 or w/e HP, but it has a turbo system that adds mass + size + complexity... S2K makes 240HP but that head + cam + the level of engineering needed to make that kind of power = $$$$ + big ass head + not that great gas mileage)..
You have to look at the whole picture... when you start looking at details that are meaningless outside of the context of engine operation the discussion goes to shit.
You apparently missed my point. It is that comparing engines alone is a complex matter without making it worse by saying "Well car XXX does this and car YYY does that, so ZZZ must be better!" because there are even more variable involved once you include the vehicle itself. That's the point I've been trying to make. Add forced induction and it gets even more mind numbing.
Yeah, why should it be compared cc to cc? Why not take any other engine parameter and compare it by that?
Let's just compare motors based on throttle size, or cam profile. It's pointless to pick displacement when so much more affects gas mileage than just displacement. Pushrods are the perfect example of this.
Quote from: MrH on June 25, 2009, 09:50:31 AM
How does that not make sense? If a larger displacement pushrod can be competitive in every single category as a smaller displacement OHC engine, who gives a fuck what the displacement is? Usually more displacement would mean worst gas mileage, but miraculously, they don't get horrible gas mileage. Imagine that.
so if your in a race series with a 3L normally aspirated engine rule - are you going to pick an OHV engine or an OHC engine
Quote from: sportyaccordy on June 25, 2009, 10:51:03 AM
You as an auto tech should know as well as anyone the differences valvetrain design make in overall engine size.
Being an auto tech doesn't necessarily mean I know anything other than how to diagnose and repair problems with a vehicle. I do nothing having to do with high performance engine building or tuning, so my knowledge is very limited. I just understand a few basic principles on the matter.
Quote from: r0tor on June 25, 2009, 11:01:03 AM
so if your in a race series with a 3L normally aspirated engine rule - are you going to pick an OHV engine or an OHC engine
What does this have to do with anything... when did anyone say an OHV would be more efficient than OHC for a given displacement
How about this since we're throwing around meaningless hypothetical situations
You're in a race where you have 1 chassis choice(say, an RX-7 or an E36 BMW) but any engine choice as long as its a V8... are you gonna spend $20K to source, prep + shoehorn in a DOHC V8 or make the same power + burn the same gas + pay half the price with a bolt on LSx motor + tranny
Every f'in race class has displacement restrictions and in any form of non-spec racing, there is going to be a team that forks out the $$$ to build the most powerful engine they can and in just about every racing series that is an OHC engine
The only two exceptions I can think of are Top Fuel and NASCAR.
Quote from: R-inge on June 24, 2009, 04:35:04 PM
Well it looks like you're the one who's incorrect. My widdle WRX apparently will walk on a Corvette in top gear. :evildude:
Unfortunately, if you pull up beside a Corvette on the highway and try to call him out, it might be difficult to convince him that downshifting is NOT allowed. ;)
Which makes me wonder why anyone cares about the acceleration times of people too stupid to use the gearbox. :thumbsup:
And another thing. If OHV engines are so shitty that only two manufacturers use them, how shitty a design would an engine need to be for only one manufacturer to use it?
:popcorn:
Quote from: R-inge on June 25, 2009, 01:04:04 PM
The only two exceptions I can think of are Top Fuel and NASCAR.
and both of those series requires OHV engines
Quote from: Cobra93 on June 25, 2009, 01:18:48 PM
Unfortunately, if you pull up beside a Corvette on the highway and try to call him out, it might be difficult to convince him that downshifting is NOT allowed. ;)
Which makes me wonder why anyone cares about the acceleration times of people too stupid to use the gearbox. :thumbsup:
I'm with ya there. Apparently the only reason it came up was because someone thought it was a good metric to compare the Vette to world class OHC supercars.
Quote from: MrH on June 25, 2009, 01:53:51 AM
I have presented my argument countless times. Numerous examples have been provided to show that a pushrod is neither larger or heavier than a OHC design. Examples have also been provided to show that top gear acceleration isn't any worse than many high performing OHC engines. Power and fuel economy numbers are comparable to OHC engines.
It's pointless to bring displacement of volumetric efficiency into this. It's over complicating a simple issue. If size, weight, power delivery, and gas mileage are all relatively comparable, how is it so definitively inferior?
I don't want to seem like I'm picking on you, but this is simply not correct, and is again very illustrative of why this thread has trundled on as it has for well more than a dozen pages...
Can you imagine a power train design team, with a budget of say $250MM (Hyundai's budget to develop the new 4.6L Tau V8 IIRC) and a staff of ~100 engineers saying such things?
Engineering is not "over complicating." It is what it is, and without some of these basic fundamentals (such as basic knowledge of the Otto cycle) this thread is bound to trundle on for another dozen pages as it has.
Quote from: r0tor on June 25, 2009, 01:27:20 PM
and both of those series requires OHV engines
Try rebuilding an OHC engine in 45 minutes. ;)
Quote from: R-inge on June 25, 2009, 01:58:16 PM
I'm with ya there. Apparently the only reason it came up was because someone thought it was a good metric to compare the Vette to world class OHC supercars.
Yes, how dare the plebian Corvette, with it's antiquated pushrod engine and lowly leaf spring suspension, post performance numbers competitive with those world class supercars.
:rage: :rage: :rage:
Quote from: Cobra93 on June 25, 2009, 02:30:46 PM
Yes, how dare the plebian Corvette, with it's antiquated pushrod engine and lowly leaf spring suspension, post performance numbers competitive with those world class supercars.
:rage: :rage: :rage:
and get spanked by a mazdaspeed3 in the process :rastaman:
Quote from: r0tor on June 25, 2009, 11:01:03 AM
so if your in a race series with a 3L normally aspirated engine rule - are you going to pick an OHV engine or an OHC engine
We're not running in a 3.0 liter naturally aspirated race... :huh:
Seriously, that's not even close to what we're discussing. We're discussing street cars.... :confused:
Quote from: MrH on June 25, 2009, 04:34:11 PM
We're not running in a 3.0 liter naturally aspirated race... :huh:
Seriously, that's not even close to what we're discussing. We're discussing street cars.... :confused:
No we're not talking about street cars, we're talking about the superiority of one engine design over another. Keep your head on straight big guy.
Quote from: R-inge on June 25, 2009, 01:04:04 PM
The only two exceptions I can think of are Top Fuel and NASCAR.
Where OHC is explicitly forbidden...
Quote from: hotrodalex on June 25, 2009, 04:47:50 PM
What racing series besides Top Fuel involve engine rebuilds multiple times per day? I'm serious, I can't think of any but maybe you guys can enlighten me. Normally once you grenade an engine you're done for the day, and you have till next race to put a new one together, I thought. So I don't see the point of arguing over that either.
Quote from: hotrodalex on June 25, 2009, 09:33:24 AM
The OHC engine is not superior in that application. Just like the Corvette vs others. The Corvette (with pushrods) performs equally well as the other cars with OHC engines. So neither is inferior, in those applications.
I can agree that modern 4 cyl and 6 cyl OHV engines are not up to standards set by modern OHC engines. Sadly I'm not sure if it's due to the design or GM's crap engineering. If GM had been a strong company producing strong, solid, quality products the past 20 years then we would know, but that wasn't the case. The cars that used the 4-6 cyl pushrod engines weren't so good themselves, so I doubt they put much effort into the engine either.
And here's the problem. I'm not talking about "in that application", I'm talking about engine and engine design on the whole. "Inferior" does not mean "inadequate". A flathead is perfectly adequate for use in a lawnmower, but from a technical standpoint it's an inferior engine/valvetrain design compared to the OHV engine. A pushrod is perfectly adequate in many automotive applications, but that doesn't mean it's not inferior to an OHC multivalve design.
Quote from: R-inge on June 25, 2009, 04:49:26 PM
What racing series besides Top Fuel involve engine rebuilds multiple times per day? I'm serious, I can't think of any but maybe you guys can enlighten me. Normally once you grenade an engine you're done for the day, and you have till next race to put a new one together, I thought. So I don't see the point of arguing over that either.
Top Fuel was all I was talking about with that post. Nothing more.
Quote from: MX793 on June 25, 2009, 04:51:06 PM
And here's the problem. I'm not talking about "in that application", I'm talking about engine and engine design on the whole. "Inferior" does not mean "inadequate". A flathead is perfectly adequate for use in a lawnmower, but from a technical standpoint it's an inferior engine/valvetrain design compared to the OHV engine. A pushrod is perfectly adequate in many automotive applications, but that doesn't mean it's not inferior to an OHC multivalve design.
But you cannot really debate on the whole, as there are so many different factors to the engines and different applications. Read this thread for proof.
Quote from: r0tor on June 25, 2009, 04:14:03 PM
and get spanked by a mazdaspeed3 in the process :rastaman:
I'll try this again. Upon close examination, one will find, atop the gearshift lever a cryptic diagram comprised of lines and numbers. Therein lies the secret to optimal acceleration. If that's too difficult to decode, perhaps an automatic transmission is your best choice. :rastaman:
OHV did extremely well in the GT1 class at Lemans. The C6R's and C5R's had a pretty dominant run, and the ORECA Vipers dominated the series before that.
the OHC's in Prodrives Ferrari and the Aston Martin did just as well at LeMans....
Quote from: r0tor on June 26, 2009, 05:41:52 AM
the OHC's in Prodrives Ferrari and the Aston Martin did just as well at LeMans....
So they both did well.... Meaning both are just as good for that application.
I swear to god, some of you guys had a wild band of pushrods anally rape your mother and you haven't gotten over it yet...
It's a slightly fucking different way of exploding dead dinosaurs, and it seems to work just fine on the street and on the track. GET THE FUCK OVER IT, ALREADY!
Quote from: r0tor on June 26, 2009, 05:41:52 AM
the OHC's in Prodrives Ferrari and the Aston Martin did just as well at LeMans....
If by "just as well" you mean winning less, with newer cars.... then yes.
Quote from: ChrisV on June 26, 2009, 07:44:54 AM
I swear to god, some of you guys had a wild band of pushrods anally rape your mother and you haven't gotten over it yet...
It's a slightly fucking different way of exploding dead dinosaurs, and it seems to work just fine on the street and on the track. GET THE FUCK OVER IT, ALREADY!
The vitriol has come almost from entirely your side and it's owing to the reticent and/or inability to reconcile fundamental engineering concepts explaining why there are only two pushrod engines left in automobiledom. It is actually you and yours that have to get over it; pushrods are a dying breed, and are on the precipice of being extinct.
Quote from: hotrodalex on June 25, 2009, 04:47:50 PM
Actually with a couple of extra set of heads it might be faster. As cougs previosuly before all of the valve train could be assembled and the heads just slapped on and tightened down.
This could be much faster than having to adjust each valve once the head and cams are bolted into or on the engine.
As far as rebuildng faster.
Actually with a couple of extra set of heads OHC might be faster. As cougs mentioned before all of the valve train could be assembled and the heads just slapped on and tightened down.
This could be much faster than having to adjust each valve once the head and cams are bolted into or on the engine.
Quote from: SVT32V on June 26, 2009, 10:33:56 AM
As far as rebuildng faster.
Actually with a couple of extra set of heads OHC might be faster. As cougs mentioned before all of the valve train could be assembled and the heads just slapped on and tightened down.
This could be much faster than having to adjust each valve once the head and cams are bolted into or on the engine.
Yup, just line up the timing marks and put on the cam chain/belt. Valves could be pre-adjusted and ready to go.
No, parallel processing is verboten (sorry MrH, just couldn't resist).
Bet your bottom dollar being able to fully dress heads independent of the engine block is a labor cost savings for automakers.
Quote from: GoCougs on June 26, 2009, 10:16:28 AM
The vitriol has come almost from entirely your side and it's owing to the reticent and/or inability to reconcile fundamental engineering concepts explaining why there are only two pushrod engines left in automobiledom. It is actually you and yours that have to get over it; pushrods are a dying breed, and are on the precipice of being extinct.
Let us not forget the regulatory advantage OHC engines enjoy as a reason for this in many countries outside of the US, and probably very soon, inside the US.
Also, there are more than two OHV engines being produced;
LS7
5.7 Hemi
6.1 Hemi
1.3 Kent Crossflow
Ok, it is only FOUR, but there are still more than two being produced. :lol:
Isn't the Malibu V6 pushrod?
You have me on that one, Raza. Which engine? I assume there is more than one, right?
Quote from: Raza on June 26, 2009, 09:29:55 PM
Isn't the Malibu V6 pushrod?
No, the Malibu uses the High Feature V6, which is DOHC. The Impala does use two pushrod V6 engines, a 3.5L and a 3.9L (same family, different displacements).
By the way, the wife says the 3.6 is a VVT DOHC engine.
Quote from: The Pirate on June 26, 2009, 09:41:16 PM
No, the Malibu uses the High Feature V6, which is DOHC. The Impala does use two pushrod V6 engines, a 3.5L and a 3.9L (same family, different displacements).
The wife also believes the 6000, the 6200 and the 8100 are also all OHV engines.
Quote from: hounddog on June 26, 2009, 09:51:18 PM
The wife also believes the 6000, the 6200 and the 8100 are also all OHV engines.
They all are, but that's really only one engine as they are all in the Vortec family.
So is the 5300. You cannot possibly tell me the 8100 is the same engine as the 5300 because it says "Vortec" on it?
Wifee says they are called Vortech BECAUSE they are derived from the same OHV; the 4.3 V6 Vortech. She says they use the same "vortex technology cylinders."
Quote from: hounddog on June 26, 2009, 10:05:25 PM
So is the 5300. You cannot possibly tell me the 8100 is the same engine as the 5300 because it says "Vortec" on it?
Wifee says they are called Vortech BECAUSE they are derived from the same OHV; the 4.3 V6 Vortech. She says they use the same "vortex technology cylinders."
No, it's obviously not the same engine. But they are all pushrod V8 engines that are in the same family and are more or less a similar design, and all manufactured by GM. I'm not sure about all the engines in the line-up, but the 4800 and the 5300 are made from the same basic block (obviously bore and stroke changes) and the 6000 is a bored out 5300. The 8100 is likely a separate block, but for the purposes of the discussion (how many pushrod engines are in production today), they would all be considered one engine, IMO.
Likewise, the 4.6L and 5.4L Modular V8s from Ford could be considered one engine if one was counting the number of OHC engines in production.
That is fair, but it is not quite right.
Engines which are similar, but significantly different are in fact different engines. The small blocks could be counted as one, however, the 8100 is a big block, and therefore is significantly different making it a seperate engine.
For instance, would you call the 4.3l V6 the "same" engine as the 6000 Vortech simply because it shares the same cylinder technology?
New OHV engine count:
LS7
5.7 Hemi
6.1 Hemi
1.3 Kent Crossflow
Small block GM V8s
8100 Vortech
Fair?
1.3 Kent Crossflow?
It is used in the Ford Ka.
Also, diesels, OHV?
I know the Cummins is, and I think Mercedes diesels are also OHV. Do those count?
Also, to be fair, OHC engines are OHV engines, as none of them are L-heads (flatheads, or valve-in-block). OHC is a subset of OHV.
:devil: ;) :lol:
Quote from: The Pirate on June 26, 2009, 09:56:20 PM
They all are, but that's really only one engine as they are all in the Vortec family.
The small blocks are all essentially the same engine, but the 8100 is a big block. GM markets it as a Vortec, but it's not the same engine family as the 4800/5300/6000/6200, which are members of the classic SBC family.
It's sort of like how Ford markets both its 4 cylinders and V6s as Duratecs. A Duratec30 and a Duratec20 are obviously not the same engine family. Even sticking with the V6s, the Duratec30 shares essentially nothing with with the larger Duratec35 and Duratec37.
I want to take 8 flathead lawnmower engines and put them together. Straight 8 Briggs n Stratton with 40 hp! :wub:
Quote from: hounddog on June 26, 2009, 10:38:25 PM
That is fair, but it is not quite right.
Engines which are similar, but significantly different are in fact different engines. The small blocks could be counted as one, however, the 8100 is a big block, and therefore is significantly different making it a seperate engine.
For instance, would you call the 4.3l V6 the "same" engine as the 6000 Vortech simply because it shares the same cylinder technology?
New OHV engine count:
LS7
5.7 Hemi
6.1 Hemi
1.3 Kent Crossflow
Small block GM V8s
8100 Vortech
Fair?
The Kent is new? They may still be building it, but that motor dates back to the 60s, the Crossflow going back to the 70s. It's not a remotely recently created engine line. It hasn't even been updated in nearly 15 years.
Dodge's current Hemi line is a recently created pushrod engine family. Chevy's SBC, while not new, has been continuously updated with new iterations released recently. I'd also add the GM High-Value V6s (3.5 and 3.9) which replaced the older 3100/3400 and 3800 families over the past couple of years.
And the 5.7 and 6.1 Hemis are the same basic engine. The LS7 is part of the SBC family. Not sure why you're counting them as separate engines.
Quote from: MX793 on June 27, 2009, 08:08:46 AM
The Kent is new? They may still be building it, but that motor dates back to the 60s, the Crossflow going back to the 70s. It's not a remotely recently created engine line. It hasn't even been updated in nearly 15 years.
Dodge's current Hemi line is a recently created pushrod engine family. Chevy's SBC, while not new, has been continuously updated with new iterations released recently. I'd also add the GM High-Value V6s (3.5 and 3.9) which replaced the older 3100/3400 and 3800 families over the past couple of years.
And the 5.7 and 6.1 Hemis are the same basic engine. The LS7 is part of the SBC family. Not sure why you're counting them as separate engines.
I did not say the Kent was new, I said it was a new OHV count (read; list).
The two Hemis are significantly different, with the 5.7 being the standard truck engine and the 6.1 being a high performance engine with very different workings. The only thing these two engines really only share is a block, most of the parts in the 6.1 are racing inspired and are very different from those used in the 5.7.
Also, the LS7 is significantly different from its cousins and not much of it is the same as the truck engines. It uses a seperate and distinct casting for its block, and utilizes racing technology to greatly upgrade its abilities. Same goes for the 6.1 Hemi parts, and both the ls7 and 6.1 are mostly hand built.
New OHV engine count:
LS7
5.7 Hemi
6.1 Hemi
1.3 Kent Crossflow
Small block GM V8s
8100 Vortech
High Value GM family
Quote from: hounddog on June 27, 2009, 12:05:50 AM
It is used in the Ford Ka.
Oh, interesting. I thought it was a bit large for a lawnmower engine. :lol:
GM's 4.3L pushrod V-6 I'd almost consider by itself - it's based upon the original Chevy small-block and has cast iron heads and block - the newer V-8 engines have aluminum heads and are several generations newer.
Quote from: hounddog on June 27, 2009, 08:32:06 AM
I did not say the Kent was new, I said it was a new OHV count (read; list).
The two Hemis are significantly different, with the 5.7 being the standard truck engine and the 6.1 being a high performance engine with very different workings. The only thing these two engines really only share is a block, most of the parts in the 6.1 are racing inspired and are very different from those used in the 5.7.
Also, the LS7 is significantly different from its cousins and not much of it is the same as the truck engines. It uses a seperate and distinct casting for its block, and utilizes racing technology to greatly upgrade its abilities. Same goes for the 6.1 Hemi parts, and both the ls7 and 6.1 are mostly hand built.
The basic architecture is still the same though, so I'd put them in the same family in each instance.
Quote from: hounddog on June 26, 2009, 10:38:25 PM
That is fair, but it is not quite right.
Engines which are similar, but significantly different are in fact different engines. The small blocks could be counted as one, however, the 8100 is a big block, and therefore is significantly different making it a seperate engine.
For instance, would you call the 4.3l V6 the "same" engine as the 6000 Vortech simply because it shares the same cylinder technology?
New OHV engine count:
LS7
5.7 Hemi
6.1 Hemi
1.3 Kent Crossflow
Small block GM V8s
8100 Vortech
Fair?
Yes, that makes sense. Though if the 5.7 Hemi and 6.1 Hemi are the same block and basic construction, I'd consider those the same engine, but I don't know enough about that engine series to say conclusively one way or the other. Also, I would put the 4.3L V6 in it's own category, as it's an older design that shares little (if anything) with the current SBCs. I didn't think it was still in production, but a quick search shows it's the base engine for the GMT900 pick up trucks.
I thought that the 8100 did share some stuff with the smaller engines, but some research shows that not to be the case (and it certainly makes sense now that I think about it), so that's definitely a standalone engine.
Additionally, the 8100 is no longer in production so go ahead and take that off your lists.
Oops nevermind, apparently Uhaul still gets it in one of their trucks.
Okay, looks like I created a bit of an issue. What I meant by only "two" pushrod engines are two recent/new engine families. The Chrysler 5.7/6.1 Hemi and the GM LSx.
There definitely other pushrod engines still produced but they are all ancient throwbacks (or derivatives thereof); Chrysler's 3.8L V6, GM's 3.4L V6, and a few others. The 8100 is a version of the ancient Chevy big block (396 - 454).
Quote from: GoCougs on June 27, 2009, 12:21:30 PM
Okay, looks like I created a bit of an issue. What I meant by only "two" pushrod engines are two recent/new engine families. The Chrysler 5.7/6.1 Hemi and the GM LSx.
There definitely other pushrod engines still produced but they are all ancient throwbacks (or derivatives thereof); Chrysler's 3.8L V6, GM's 3.4L V6, and a few others. The 8100 is a version of the ancient Chevy big block (396 - 454).
Well, you know with this crowd we use critically thinking only occasionally when it serves our purposes... otherwise more people would have realized what you meant, rather than continuing to drag on the discussion.
Quote from: GoCougs on June 27, 2009, 12:21:30 PM
Okay, looks like I created a bit of an issue. What I meant by only "two" pushrod engines are two recent/new engine families. The Chrysler 5.7/6.1 Hemi and the GM LSx.
There definitely other pushrod engines still produced but they are all ancient throwbacks (or derivatives thereof); Chrysler's 3.8L V6, GM's 3.4L V6, and a few others. The 8100 is a version of the ancient Chevy big block (396 - 454).
And, as I have pointed out, a very large number of OHC engines are also ancient throwbacks. At least they are direct decendants of ancient machines.
There are zero modern, or "new," engine designs on the market with every design having at least 50 years on them now.
Quote from: R-inge on June 27, 2009, 12:24:11 PM
Well, you know with this crowd we use critically thinking only occasionally when it serves our purposes... otherwise more people would have realized what you meant, rather than continuing to drag on the discussion.
Actually, I started with a lighthearted quip regarding numbers being built. From there it turned into the first civil discussion in this thread, not sure why you see that as a problem? :huh:
Quote from: hounddog on June 27, 2009, 12:52:55 PM
Actually, I started with a lighthearted quip regarding numbers being built. From there it turned into the first civil discussion in this thread, not sure why you see that as a problem? :huh:
Sorry, that was a bit too snarky, my bad.
This whole thread is just one series of nitpicks after another. Ultimately the primary point still holds true, which is that OHV engines are gradually dying out in favor of OHC designs.
Ahh, not a big deal especially now that you clarified.
I do not think anyone here could logically argue the OHV engines are a dying breed. However, there are more reasons why than simply the OHC engine is better, which may or may not be true depending on application.
Favorable regulation for the OHC, misconception about both engines and general ignorance on the consumers part have a great deal to do with it.
There are certain situations where I would not want an OHC, and there are others where I would not want a OHV.
Quote from: hounddog on June 27, 2009, 01:23:11 PM
Ahh, not a big deal especially now that you clarified.
I do not think anyone here could logically argue the OHV engines are a dying breed. However, there are more reasons why than simply the OHC engine is better, which may or may not be true depending on application.
Favorable regulation for the OHC, misconception about both engines and general ignorance on the consumers part have a great deal to do with it.
There are certain situations where I would not want an OHC, and there are others where I would not want a OHV.
Yeah, there is a place for both, and I bet GM keeps them around for a while (not to mention Chrysler) but who knows what will happen after that.
Quote from: GoCougs on June 26, 2009, 02:49:24 PM
No, parallel processing is verboten (sorry MrH, just couldn't resist).
Bet your bottom dollar being able to fully dress heads independent of the engine block is a labor cost savings for automakers.
You never explained how parallel processing reduces cost in manufacturing. I tried to drag it out of you for 7 pages, but apparently you refuse to.
It only reduces inventory between processes. I'd still like to hear your answer.
Lean manufacturing 101.
Quote from: MrH on June 27, 2009, 01:34:48 PM
You never explained how parallel processing reduces cost in manufacturing. I tried to drag it out of you for 7 pages, but apparently you refuse to.
It only reduces inventory between processes. I'd still like to hear your answer.
IMO it would work like this: with an OHC engine, one team can be working on assembling the engine while another team assembles the heads with a complete valve train. Final assembly would just require installing the timing chain and covers, pulleys, and drop into the engine. With OHV much more of the engine assembly time is taken up by setting up the cam, lifters, and pushrods in the engine assembly. The heads are comparatively simple to assemble since they just have the valves and springs.
Sooo.... if you can have less overlap between jobs while assembling a part (lets call it modular) you can have two workers assembling an engine in less overall time. Maybe I misunderstand the principles involved, correct me if I'm wrong.
Shortest possible answer;
Parallel processing cuts costs when the constraint machine is mirrored, then that decreases throughput time and increases capacity, which in turn decreases inventory.
One person should be able to run both the constraint machine and duplicate machine, which would also cut throughput time.
As for product development;
If you run parallel processes (concurring engineering) and focus on reduction of the cycle time on the critical path, it allows a product to be brought to market sooner, therefore, reducing product development costs and increasing the likelihood of capturing a large portion of market share before competition is introduced into the marketplace.
Quote from: hounddog on June 26, 2009, 10:05:25 PM
So is the 5300. You cannot possibly tell me the 8100 is the same engine as the 5300 because it says "Vortec" on it?
Wifee says they are called Vortech BECAUSE they are derived from the same OHV; the 4.3 V6 Vortech. She says they use the same "vortex technology cylinders."
Sigh. I wish I could ask my wife for automotive facts.
She must be about as rare as a unicorn in a, uhm, pyjamas. Nice find :ohyeah:
I know. ;)
She tells me that all the time.
Quote from: R-inge on June 27, 2009, 01:12:14 PM
This whole thread is just one series of nitpicks after another. Ultimately the primary point still holds true, which is that OHV engines are gradually dying out in favor of OHC designs.
Lol! Which is why I'm being nitpicky when I mention again that all OHC engines are OHV engines. Overhead Valve vs Overhead Cam (and the valves are still overhead). it's OHV vs CiB, or pushrod. It'd be nice if supposedly knowledgeable automotive fans would at least get the terminology right...
:lol: :evildude:
Quote from: ChrisV on June 27, 2009, 02:26:16 PM
Lol! Which is why I'm being nitpicky when I mention again that all OHC engines are OHV engines. Overhead Valve vs Overhead Cam (and the valves are still overhead). it's OHV vs CiB, or pushrod. It'd be nice if supposedly knowledgeable automotive fans would at least get the terminology right...
:lol: :evildude:
http://en.wikipedia.org/wiki/Ohv
"An overhead valve (OHV) engine, also called pushrod engine or I-head engine is a type of piston engine that places the camshaft in the cylinder block (usually beside and slightly above the crankshaft in a straight engine or directly above the crankshaft in the V of a V engine) and uses pushrods or rods to actuate rocker arms above the cylinder head to actuate the valves. Lifters or tappets reside in the engine block between the camshaft and pushrods. The later overhead cam (OHC) design avoids the use of pushrods by putting the camshaft in the cylinder head."
OHV sounds a lot like a pushrod engine to me. :huh:
And you aren't the one who sets the standard for "knowledgeable automotive fans" thank God.
Quote from: R-inge on June 27, 2009, 02:33:50 PM
http://en.wikipedia.org/wiki/Ohv
"An overhead valve (OHV) engine, also called pushrod engine or I-head engine is a type of piston engine that places the camshaft in the cylinder block (usually beside and slightly above the crankshaft in a straight engine or directly above the crankshaft in the V of a V engine) and uses pushrods or rods to actuate rocker arms above the cylinder head to actuate the valves. Lifters or tappets reside in the engine block between the camshaft and pushrods. The later overhead cam (OHC) design avoids the use of pushrods by putting the camshaft in the cylinder head."
OHV sounds a lot like a pushrod engine to me. :huh:
And you aren't the one who sets the standard for "knowledgeable automotive fans" thank God.
I think he means that an ohc also has over head valves (ohv), as opposed to a flathead.
Quote from: mzziaz on June 27, 2009, 02:43:09 PM
I think he means that an ohc also has over head valves (ohv), as opposed to a flathead.
Sure it does, anyone who knows anything about engines knows that. The point is that OHV is the common shorthand for pushrod engines. Any knowledgeable automotive enthusiast should know that.
BTW Chris, I'm not interested in derailing this thread on your account so if you have anything else to say on the matter shoot me a PM, though I won't likely respond. I won't waste anymore time on you here. :rolleyes:
Quote from: R-inge on June 27, 2009, 02:33:50 PM
http://en.wikipedia.org/wiki/Ohv
"An overhead valve (OHV) engine, also called pushrod engine or I-head engine is a type of piston engine that places the camshaft in the cylinder block (usually beside and slightly above the crankshaft in a straight engine or directly above the crankshaft in the V of a V engine) and uses pushrods or rods to actuate rocker arms above the cylinder head to actuate the valves. Lifters or tappets reside in the engine block between the camshaft and pushrods. The later overhead cam (OHC) design avoids the use of pushrods by putting the camshaft in the cylinder head."
OHV sounds a lot like a pushrod engine to me. :huh:
And you aren't the one who sets the standard for "knowledgeable automotive fans" thank God.
I wouldn't take that wiki article verbatim. According to that, the pushrod OHV is an older design than the OHC OHV, which is incorrect.
However, it is generally accepted terminology that OHV = pushrod. The pushrod was essentially a way to retrofit the overhead valves of an OHC motor onto a cam-in-block flathead design. OHV indicates that the valves are overhead but the cam is not.
Quote from: MX793 on June 27, 2009, 03:04:07 PM
I wouldn't take that wiki article verbatim. According to that, the pushrod OHV is an older design than the OHC OHV, which is incorrect.
However, it is generally accepted terminology that OHV = pushrod. The pushrod was essentially a way to retrofit the overhead valves of an OHC motor onto a cam-in-block flathead design. OHV indicates that the valves are overhead but the cam is not.
Yep, that's all I was going for.
Quote from: R-inge on June 27, 2009, 02:54:07 PM
Sure it does, anyone who knows anything about engines knows that. The point is that OHV is the common shorthand for pushrod engines. Any knowledgeable automotive enthusiast should know that.
Boy, smilies indicating lighthearted ribbing are sure wasted on some people around here.... :rolleyes: Guess I won't try that anymore...
Yes, OHV
is shorthand for pushrods. And it
became shorthand because people were to fucking lazy to use the correct terminology. Kind of like how roadster now means any fucking convertible with slightly sporting intentions.
Go fuck yerself. I mean that. :banghead:
Quote from: ChrisV on June 27, 2009, 05:07:58 PM
Boy, smilies indicating lighthearted ribbing are sure wasted on some people around here.... :rolleyes: Guess I won't try that anymore...
Yes, OHV is shorthand for pushrods. And it became shorthand because people were to fucking lazy to use the correct terminology. Kind of like how roadster now means any fucking convertible with slightly sporting intentions.
Go fuck yerself. I mean that. :banghead:
Yeah it seemed like R-inge overreacted there. :huh:
One of the few times you're joking around and people still get mad at you. :huh:
In any case, your BMW has an OHV engine. How do you feel about that? :devil:
Quote from: thecarnut on June 27, 2009, 05:16:03 PM
Yeah it seemed like R-inge overreacted there. :huh:
One of the few times you're joking around and people still get mad at you. :huh:
Actually I joke around quite a bit, but when I want to emphasize that, I put in the smilies, 'cause it's hard to read intent on the web. Oh well.
Quote
In any case, your BMW has an OHV engine. How do you feel about that? :devil:
All I care about is that it continues running and does the job it's asked to do. :lol:
Wonder what it'd be like with a supercharged big block Chevy? :winkguy:
Quote from: ChrisV on June 27, 2009, 05:31:11 PM
Actually I joke around quite a bit, but when I want to emphasize that, I put in the smilies, 'cause it's hard to read intent on the web. Oh well.
All I care about is that it continues running and does the job it's asked to do. :lol:
Wonder what it'd be like with a supercharged big block Chevy? :winkguy:
:nono:
Manual transmission swap. Maybe put in a rotary too for good measure. :lol:
Quote from: hounddog on June 27, 2009, 12:52:01 PM
And, as I have pointed out, a very large number of OHC engines are also ancient throwbacks. At least they are direct decendants of ancient machines.
There are zero modern, or "new," engine designs on the market with every design having at least 50 years on them now.
But in terms of new engine families, i.e., that which the automakers have invested in recently, only two have been pushrod (Hemi an LSx); all others have been OHC.
Quote from: MrH on June 27, 2009, 01:34:48 PM
You never explained how parallel processing reduces cost in manufacturing. I tried to drag it out of you for 7 pages, but apparently you refuse to.
It only reduces inventory between processes. I'd still like to hear your answer.
I did, and it is duplicated below by others:
Quote from: hounddog on June 27, 2009, 01:37:30 PM
Lean manufacturing 101.
Quote from: R-inge on June 27, 2009, 01:41:28 PM
IMO it would work like this: with an OHC engine, one team can be working on assembling the engine while another team assembles the heads with a complete valve train. Final assembly would just require installing the timing chain and covers, pulleys, and drop into the engine. With OHV much more of the engine assembly time is taken up by setting up the cam, lifters, and pushrods in the engine assembly. The heads are comparatively simple to assemble since they just have the valves and springs.
Sooo.... if you can have less overlap between jobs while assembling a part (lets call it modular) you can have two workers assembling an engine in less overall time. Maybe I misunderstand the principles involved, correct me if I'm wrong.
Nice on the below, hounddog - got a bit of Theory of Constraints (http://en.wikipedia.org/wiki/Theory_of_Constraints) in there (Goldratt's
The Goal) in there, too:
Quote from: hounddog on June 27, 2009, 01:54:57 PM
Shortest possible answer;
Parallel processing cuts costs when the constraint machine is mirrored, then that decreases throughput time and increases capacity, which in turn decreases inventory.
One person should be able to run both the constraint machine and duplicate machine, which would also cut throughput time.
As for product development;
If you run parallel processes (concurring engineering) and focus on reduction of the cycle time on the critical path, it allows a product to be brought to market sooner, therefore, reducing product development costs and increasing the likelihood of capturing a large portion of market share before competition is introduced into the marketplace.
I would (again) add to the above the value in the option of outsourcing the heads as a complete sub assembly; this allows for labor and/or cost savings as they can be built on different shifts, in different areas of the plant, at a different plant, or at a supplier, allowing the supplier to save costs through balancing labor and/or reducing direct labor through scale (as in outsourcing to a supplier). This kitting value also exists for pushrod heads, but it is less since much less can be done with the heads off the engine (can't install rockers, pushrods, valve covers, coil packs and can't adjust the valves).
Quote from: ChrisV on June 27, 2009, 05:31:11 PM
Wonder what it'd be like with a supercharged big block Chevy? :winkguy:
1000+ HP would go very nicely with the car, I think.
Quote from: hotrodalex on June 28, 2009, 08:38:14 PM
1000+ HP would go very nicely with the car, I think.
Manual transmission is better.
Quote from: thecarnut on June 28, 2009, 09:01:17 PM
Manual transmission is better.
Can't have both, so power wins. He can get something else with manual.
Quote from: hotrodalex on June 28, 2009, 09:03:39 PM
Can't have both, so power wins. He can get something else with manual.
Um, no.
You can have both. V12 swap + manual + turbo.
And who are you to decide that power wins? :rage:
redneck
Quote from: thecarnut on June 28, 2009, 09:08:23 PM
Um, no.
You can have both. V12 swap + manual + turbo.
And who are you to decide that power wins? :rage:
redneck
What transmission are you using then? Most can't handle 1000+ HP.
Quote from: hotrodalex on June 28, 2009, 09:12:21 PM
What transmission are you using then? Most can't handle 1000+ HP.
I dunno but I know that Chris posted pics of the worlds fastest 7 series and it has a manual and a V12 I blv.
And who said anything about 1000+ hp? :huh:
Quote from: thecarnut on June 28, 2009, 09:13:53 PM
I dunno but I know that Chris posted pics of the worlds fastest 7 series and it has a manual and a V12 I blv.
And who said anything about 1000+ hp? :huh:
Well he said he wanted a S/C big block, so if it's any good it will put out 1000+.
One thing you have to look with big power and a manual transmission is how often do they use the power. If they rarely, if ever, use all that power than a manual can be fine. But it needs to be built up if they are going to use the power.
Quote from: hotrodalex on June 28, 2009, 09:19:24 PM
Well he said he wanted a S/C big block, so if it's any good it will put out 1000+.
One thing you have to look with big power and a manual transmission is how often do they use the power. If they rarely, if ever, use all that power than a manual can be fine. But it needs to be built up if they are going to use the power.
Yeah... the Tremec TR6060 can only take 600 lbs/ft of torque anyways. Still, a 650-700 hp, 600 lbs/ft 7 series with a 6 speed manual would be nice. :lol:
The one I posted was a manual and a supercharged V8.
And it cost $50k to get 600 hp.
I think one could do better with pushrods. ;)
Quote from: ChrisV on June 29, 2009, 06:48:28 AM
The one I posted was a manual and a supercharged V8.
And it cost $50k to get 600 hp.
I think one could do better with pushrods. ;)
Oh.
Well then just get a ZR1 drivetrain then. Hopefully someone wrecked one already. :lol:
Quote from: ChrisV on June 29, 2009, 06:48:28 AM
The one I posted was a manual and a supercharged V8.
And it cost $50k to get 600 hp.
I think one could do better with pushrods. ;)
Which V8, the one from the M5?
Yea you could cobble together some Detroit iron for prob 2/5 the price of that no problem and make the same power.
Quote from: ChrisV on June 27, 2009, 05:07:58 PM
Boy, smilies indicating lighthearted ribbing are sure wasted on some people around here.... :rolleyes: Guess I won't try that anymore...
Yes, OHV is shorthand for pushrods. And it became shorthand because people were to fucking lazy to use the correct terminology. Kind of like how roadster now means any fucking convertible with slightly sporting intentions.
Go fuck yerself. I mean that. :banghead:
So would it meet with your approval to use the diversionary "cam in block" advertising spiel?
And no, it's not shorthand. It's an accurate description as a stand alone entity, but becomes even more appropriate in context, as the displaced technology was the "underhead" valve train, where the valves were, well, under the head and in the block.
Ford flathead V8 clearly showing the valves in the block (and by extension under the head):
(http://img23.imageshack.us/img23/2744/1001063e.jpg) (http://img23.imageshack.us/i/1001063e.jpg/)
Quote from: sportyaccordy on June 29, 2009, 10:43:43 AM
Which V8, the one from the M5?
Yea you could cobble together some Detroit iron for prob 2/5 the price of that no problem and make the same power.
have you ever tried to drive a 600hp small block chevy? Hope you don't mind spending a good 10 minutes each start-up to try and get it to idle and not stall on you or have an appetite for a really high idle
Quote from: GoCougs on June 29, 2009, 10:59:22 AM
So would it meet with your approval to use the diversionary "cam in block" advertising spiel?
And no, it's not shorthand. It's an accurate description as a stand alone entity, but becomes even more appropriate in context, as the displaced technology was the "underhead" valve train, where the valves were, well, under the head and in the block.
Ford flathead V8 clearly showing the valves in the block (and by extension under the head):
(http://img23.imageshack.us/img23/2744/1001063e.jpg) (http://img23.imageshack.us/i/1001063e.jpg/)
As I said, I was playing around with him for the lulz, and put the smilies on to prove it, and was going to leave it at that. But since you're just a dick regardless....
That would be true if the ONLY tech it "displaced" was flathead engines, but since OHC engines were already around with overhead valves, that argument loses merit. The use of OHV to describe pushrods ONLY is a relatively recent development, just like the terminology of roadster meaning every sporty convertible is fairly recent.
I like all the engines, be they flathead, pushrod, OHC, or even that wonderful little magic spinning triangle one with no cam or valves. :lol: Anyone who cares enough about how the valves in an engine are actuated that they would denigrate and put down that which isn't their favorite method of valve actuation (:rolleyes:) on a constant basis is worthless waste of air that hopefully will die without passing on his genetic material.
Quote from: r0tor on June 29, 2009, 11:03:00 AM
have you ever tried to drive a 600hp small block chevy? Hope you don't mind spending a good 10 minutes each start-up to try and get it to idle and not stall on you or have an appetite for a really high idle
Actually, a 600hp modern small block with modern injection has no problems with those things. But I was talking big block. I already built a carburated big block Ford that had almost that much hp and over 700 lb ft of torque that was a smooth daily driver, as easy to drive as a stock 5.0. My 500plus hp carburated big block Chevy was also pretty smooth and easy to drive. Adding another hundred hp to it's not that much of an issue these days.
Quote from: GoCougs on June 29, 2009, 10:59:22 AM
So would it meet with your approval to use the diversionary "cam in block" advertising spiel?
And no, it's not shorthand. It's an accurate description as a stand alone entity, but becomes even more appropriate in context, as the displaced technology was the "underhead" valve train, where the valves were, well, under the head and in the block.
Ford flathead V8 clearly showing the valves in the block (and by extension under the head):
(http://img23.imageshack.us/img23/2744/1001063e.jpg) (http://img23.imageshack.us/i/1001063e.jpg/)
That looks really weird.
How do flatheads work?
Quote from: thecarnut on June 29, 2009, 11:25:46 AM
That looks really weird.
How do flatheads work?
This is a good explanation I think: http://auto.howstuffworks.com/hemi1.htm
It compares the OHV Hemi to a Flathead design, so you get a good explanation of each one and their valve train layout.
Additionally, if you're curious about the differences between the GM OHV and Chrysler Hemi OHV engines, I will explain. Give me a minute to gather material on it...
Here are some pics to illustrate: (The first two are GM, the last two are Chrysler)
(http://images.popularhotrodding.com/tech/0504phr_ls7_09_z.jpg)
(http://precisionracecomponents.com/data/images/ls7cnc1.jpg)
(http://www.crankshaftcoalition.com/wiki/images/1/10/Hemi_cylinder_head.jpg)
(http://knowltonsthunderheads.com/store/images/moparstage2hemiheadstockvalve/moparstage2hemiheadstockvalve.jpg)
Basically the head on the GM is relatively flush with a sort of wedge shape, and the valves are located side by side and enter the cylinder at the same angle. The head on the Chrysler has splayed valves and a dished opening, and the valves enter at opposite angles. This results in theoretically better airflow through the engine.
Typically OHC engines are a sort of pent-roof hemi (imagine the end profile of a house's roof) with similar arrangement to the Hemi, but with four smaller valves.
Quote from: R-inge on June 29, 2009, 11:27:06 AM
This is a good explanation I think: http://auto.howstuffworks.com/hemi1.htm
It compares the OHV Hemi to a Flathead design, so you get a good explanation of each one and their valve train layout.
Oh, cool, thanks.
It works kind of like how I imagined it would. That's really cool! It looks pretty complex though.
Quote from: ChrisV on June 29, 2009, 11:13:55 AM
As I said, I was playing around with him for the lulz, and put the smilies on to prove it, and was going to leave it at that. But since you're just a dick regardless....
That would be true if the ONLY tech it "displaced" was flathead engines, but since OHC engines were already around with overhead valves, that argument loses merit. The use of OHV to describe pushrods ONLY is a relatively recent development, just like the terminology of roadster meaning every sporty convertible is fairly recent.
I like all the engines, be they flathead, pushrod, OHC, or even that wonderful little magic spinning triangle one with no cam or valves. :lol: Anyone who cares enough about how the valves in an engine are actuated that they would denigrate and put down that which isn't their favorite method of valve actuation (:rolleyes:) on a constant basis is worthless waste of air that hopefully will die without passing on his genetic material.
But the volume of the technology displaced was overwhelmingly that of flathead, which was the vast majority if not virtually 98% of the engine technology used in the vehicles sold in the US until the 1950s.
I don't have any preference really; and in practicality can't; there are so few pushrod-powered vehicles today, most all of which aren't my cup of tea for various reasons, that I'll never have the option. Further, I'm only explaining why pushrod engines have been phased out by the world's automakers the last few decades.
Your continually bankrupt approach to discussion is entertaining - I don't think I've ever been attacked so. I gotta give you props for that.
I think Chrysler has the better pushrod design; not only due to the valve configuration but that Chrysler for decades has mounted their rocker arms on shafts (as opposed to Chevy's pedestal mount).
Quote from: GoCougs on June 29, 2009, 11:40:37 AM
Further, I'm only explaining why pushrod engines have been phased out by the world's automakers the last few decades.
Your continually bankrupt approach to discussion is entertaining - I don't think I've ever been attacked so. I gotta give you props for that.
Isn't the main reason why pushrods are phased out mainly due to government regulations and taxations? By placing high taxes on high displacement cars even if the said engine is more compact, more powerful and consume less fuel than a smaller displacement car, all in the name of fuel economy? :huh:
Quote from: R-inge on June 29, 2009, 11:27:06 AM
This is a good explanation I think: http://auto.howstuffworks.com/hemi1.htm
It compares the OHV Hemi to a Flathead design, so you get a good explanation of each one and their valve train layout.
Very good explanation. It keeps things simple and you can see everything in the pictures.
Quote from: NomisR on June 29, 2009, 11:47:44 AM
Isn't the main reason why pushrods are phased out mainly due to government regulations and taxations? By placing high taxes on high displacement cars even if the said engine is more compact, more powerful and consume less fuel than a smaller displacement car, all in the name of fuel economy? :huh:
Yes, for the most part. Also, a lot of pushrods are neglected and haven't been improved for 15-20 years. (I don't count adding more displacement as improved)
Quote from: NomisR on June 29, 2009, 11:47:44 AM
Isn't the main reason why pushrods are phased out mainly due to government regulations and taxations? By placing high taxes on high displacement cars even if the said engine is more compact, more powerful and consume less fuel than a smaller displacement car, all in the name of fuel economy? :huh:
Not really - some may have phased out due to emissions, but the LS and Hemi are new designs...
Quote from: GoCougs on June 29, 2009, 12:13:11 PM
Not really - some may have phased out due to emissions, but the LS and Hemi are new designs...
Yeah, but without the regulation and high taxation around, I'm sure more development would have been put into it. So it's really government intervention that killed the push-rod development and not the market. That's why you have American manufacturers continue to build it because US does not have such a regulation.
Ford did away with it because they're going more towards a global platform.
Quote from: NomisR on June 29, 2009, 12:18:26 PM
Yeah, but without the regulation and high taxation around, I'm sure more development would have been put into it. So it's really government intervention that killed the push-rod development and not the market. That's why you have American manufacturers continue to build it because US does not have such a regulation.
Ford did away with it because they're going more towards a global platform.
The market killed the pushrod engine; remember, Detroit built millions of pushrod I4 and V6 engines, and elsewhere they were already on their way out or were never a factor before the regulations really started kicking in ('80s)...
Quote from: GoCougs on June 29, 2009, 12:29:20 PM
The market killed the pushrod engine; remember, Detroit built millions of pushrod I4 and V6 engines, and elsewhere they were already on their way out or were never a factor before the regulations really started kicking in ('80s)...
Detroit's 4 and 6 cyl pushrods were horrible, stemming from lack of effort put into them. They said "nobody cares about these cars, so we don't have to spend money on these engines."
Quote from: ChrisV on June 29, 2009, 11:17:25 AM
Actually, a 600hp modern small block with modern injection has no problems with those things. But I was talking big block. I already built a carburated big block Ford that had almost that much hp and over 700 lb ft of torque that was a smooth daily driver, as easy to drive as a stock 5.0. My 500plus hp carburated big block Chevy was also pretty smooth and easy to drive. Adding another hundred hp to it's not that much of an issue these days.
since you put so much emphasis into real world experiences in your garage, it contridicts my experience with my best friends 550hp 2002 Firehawk with head work, big cams, and LS1edit that was attempted to be tuned with 2 seperate and very reputable shops. It was bad enough he sold the car because it was too big of a pain in the ass to actually drive everyday.
Edited the pics in my last post, realized that I posted the same one twice when I meant to post a different one.
Quote from: r0tor on June 29, 2009, 01:08:23 PM
since you put so much emphasis into real world experiences in your garage, it contridicts my experience with my best friends 550hp 2002 Firehawk with head work, big cams, and LS1edit that was attempted to be tuned with 2 seperate and very reputable shops. It was bad enough he sold the car because it was too big of a pain in the ass to actually drive everyday.
My Camaro makes 430-450hp (I've done some things to it since the last dyno so I'm not sure) and can easily be a driver. Adding a larger cam, a better flowing intake, and maybe some better heads would give it 500+ hp and still be able to drive around fairly easily. The biggest problem would be possible overheating in traffic jams.
With a big block, 600-700 hp and ft lbs of torque wouldn't be impossible at all. Just get a good cooling system and don't overdo things too much and it's feasible to drive around.
Quote from: NomisR on June 29, 2009, 11:47:44 AM
Isn't the main reason why pushrods are phased out mainly due to government regulations and taxations? By placing high taxes on high displacement cars even if the said engine is more compact, more powerful and consume less fuel than a smaller displacement car, all in the name of fuel economy? :huh:
I highly doubt that. I can't really think of any countries that still have displacement taxes. Also, the engines discussed here are mostly for the domestic market, anyway.
Quote from: hotrodalex on June 29, 2009, 02:47:01 PM
My Camaro makes 430-450hp (I've done some things to it since the last dyno so I'm not sure) and can easily be a driver. Adding a larger cam, a better flowing intake, and maybe some better heads would give it 500+ hp and still be able to drive around fairly easily. The biggest problem would be possible overheating in traffic jams.
His car was also fine at those levels... not when he dyno'd 540 at the wheels though and it just showed the sacrifices needed when you can adjust cam timing and profiles for big power.
Quote from: r0tor on June 29, 2009, 04:13:45 PM
His car was also fine at those levels... not when he dyno'd 540 at the wheels though and it just showed the sacrifices needed when you can adjust cam timing and profiles for big power.
Sounds like he just tried to do too much with the engine, which happens a lot. It wouldn't be that bad if he had done it with a big block and supercharger.
Quote from: hotrodalex on June 29, 2009, 04:42:56 PM
Sounds like he just tried to do too much with the engine, which happens a lot. It wouldn't be that bad if he had done it with a big block and supercharger.
well, it was in direct response to this attitude:
Yea you could cobble together some Detroit iron for prob 2/5 the price of that no problem and make the same power (6oo hp).
Quote from: mzziaz on June 29, 2009, 02:59:26 PM
I highly doubt that. I can't really think of any countries that still have displacement taxes. Also, the engines discussed here are mostly for the domestic market, anyway.
That's what killed them off in the first place making them not feasible for foreign consumption which still holds true.
Quote from: r0tor on June 29, 2009, 04:45:47 PM
well, it was in direct response to this attitude:
Yea you could cobble together some Detroit iron for prob 2/5 the price of that no problem and make the same power (6oo hp).
Well he is right that you can get that same power, or more, for 2/5 of the price.
http://www.usmracer.com/Turn-Key-ZZ572720R-720-HP-572-Drag-Race-Crate-Engine_p_1979.html
720 horsepower and 685 lb.-ft. of torque for 19k
I'm not sure if that would be a good engine to drive on the street, but it shows that it is very possible.
I could easily have 600hp rotary engine too... the real question is if its streetable and the answer is no in which case it becomes a moot point
Quote from: r0tor on June 29, 2009, 05:48:37 PM
I could easily have 600hp rotary engine too... the real question is if its streetable and the answer is no in which case it becomes a moot point
The point was it's only $19k.
And it could possibly be streetable.
but not to the point an OHC with variable valve timing would be... relevant to the thread at hand
Quote from: r0tor on June 29, 2009, 06:17:20 PM
but not to the point an OHC with variable valve timing would be... relevant to the thread at hand
But could you build one with that much power for $19k?
Quote from: hotrodalex on June 29, 2009, 05:14:12 PM
Well he is right that you can get that same power, or more, for 2/5 of the price.
http://www.usmracer.com/Turn-Key-ZZ572720R-720-HP-572-Drag-Race-Crate-Engine_p_1979.html
720 horsepower and 685 lb.-ft. of torque for 19k
I'm not sure if that would be a good engine to drive on the street, but it shows that it is very possible.
.714" lift, 12:1 CR, single plane intake, and a solid cam? No, not streetable.
You guys gotta give the whole price thing a rest. It doesn't add up, literally.
Quote from: NomisR on June 29, 2009, 04:49:55 PM
That's what killed them off in the first place making them not feasible for foreign consumption which still holds true.
I don't think so. For example, Ford of Europe used to have a whole lineup of pushrod engines (v6, v4, i4). That wouldn't have made sense if they had disadvanteges in legislation. And I really don't believe displacement taxes ever has been common. The biggest car markets in Europe (UK, Germany, France) certainly never had them. In Japan I belive they used to have hp-taxes.
So I really don't think legislation has killed off any pushrods.
Quote from: mzziaz on June 30, 2009, 03:52:28 AM
And I really don't believe displacement taxes ever has been common. The biggest car markets in Europe (UK, Germany, France) certainly never had them.
Britain STILL has a displacement tax on cars over 1.549 liters registered earlier than March 2001.
http://www.direct.gov.uk/en/Motoring/OwningAVehicle/HowToTaxYourVehicle/DG_10012524
Quote from: mzziaz on June 30, 2009, 03:52:28 AM
In Japan I belive they used to have hp-taxes.
So I really don't think legislation has killed off any pushrods.
In Japan cars are STILL taxed by displacement.
http://www.japan-guide.com/e/e2206.html
"Vehicle related Taxes
A prefectural automobile tax is paid annually by individuals who own a car, truck or bus. In case of passenger cars, the
amount is calculated based on the engine displacement. A municipal light vehicle tax is paid annually by individuals who own motorbikes or other motorized light vehicles. A national motor vehicle tonnage tax is paid by vehicle owners at the time of the mandatory inspections (shaken). A prefectural automobile acquisition tax is paid by persons when they acquire a car."
http://www.gotjapan.com/living/owning_a_car.php
Taxes
There are three taxes you should be aware of when you own an automobile in Japan. They are:
1) Car Tax - The owner of a car is taxed every year on April 1.
The tax amount is decided by the size of the engine displacement and the purpose of the car's use.
2) Car Weight Tax - When your car goes through the mandatory automobile inspection, tax is charged according to the weight of the car. You have to pay the tax at the time of registration, and when you have a compulsory automobile inspection.
3) Car Acquisition Tax - Regardless of whether the car is new or second-hand, you will be charged this tax when you buy a car. You have to pay the tax when you register the car.
:) I stand corrected.
Quote from: hotrodalex on June 29, 2009, 06:19:48 PM
But could you build one with that much power for $19k?
How about a SUPERCHARGED 5.4L - ROMEO 605 FORD RACING PERFORMANCE CRATE ENGINE ASSEMBLY
only $18,150.00
# 605 hp supercharged 5.4L DOHC engine
# 550 lbs/ft of torque
http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=10261
I guaruntee it will be very streatable, relaible, and is bolts into any mod motor v8 drivetrain.
Quote from: SVT32V on June 30, 2009, 01:41:08 PM
How about a SUPERCHARGED 5.4L - ROMEO 605 FORD RACING PERFORMANCE CRATE ENGINE ASSEMBLY
only $18,150.00
# 605 hp supercharged 5.4L DOHC engine
# 550 lbs/ft of torque
http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=10261
I guaruntee it will be very streatable, relaible, and is bolt into any mod motor v8 drivetrain.
Forced Induction FTW! :rockon:
Quote from: SVT32V on June 30, 2009, 01:41:08 PM
How about a SUPERCHARGED 5.4L - ROMEO 605 FORD RACING PERFORMANCE CRATE ENGINE ASSEMBLY
only $18,150.00
# 605 hp supercharged 5.4L DOHC engine
# 550 lbs/ft of torque
http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=10261
I guaruntee it will be very streatable, relaible, and is bolts into any mod motor v8 drivetrain.
How about an N/A engine making more power than that for only $13k?
http://www.jegs.com/p/Edelbrock/Edelbrock-Pat-Musi-555ci-650HP-Carbureted-Engine/887183/10002/-1
Quote from: hotrodalex on June 30, 2009, 03:18:02 PM
How about an N/A engine making more power than that for only $13k?
http://www.jegs.com/p/Edelbrock/Edelbrock-Pat-Musi-555ci-650HP-Carbureted-Engine/887183/10002/-1
Nice engine, although I would trust one from Ford or Chevy much more.
650 hp is only a blower pulley away on the Ford 5.4
Also as much as I like carbed engines, this is only legal in historic cars not anything late model, this one is an emissions fail.
Quote from: R-inge on June 30, 2009, 02:34:52 PM
Forced Induction FTW! :rockon:
Since we're going there, how about an LS9?
Quote from: Cobra93 on June 30, 2009, 03:44:02 PM
Since we're going there, how about an LS9?
I was actually going to post that next.
Quote from: Cobra93 on June 30, 2009, 03:44:02 PM
Since we're going there, how about an LS9?
Might as well. Only way to make big, streetable power seems to be a blower.
how about the bugatti engine then...
Quote from: r0tor on June 30, 2009, 04:09:37 PM
how about the bugatti engine then...
Didn't think of that. But having 4 turbos seems to help.
I was just waiting for some 'tard to say "wut abowt teh supra!?" in which case I'd say No, not streetable power if you have a snail so big it could swallow whole children. I like my power to come on when I depress the Go pedal, not sit there waiting for 15 seconds for the turbo to wake up.
Quote from: hotrodalex on June 30, 2009, 03:18:02 PM
How about an N/A engine making more power than that for only $13k?
http://www.jegs.com/p/Edelbrock/Edelbrock-Pat-Musi-555ci-650HP-Carbureted-Engine/887183/10002/-1
Except with the S/C 5.4L you're getting a warrantable engine designed to last 100,000+ miles. That engine is neither.
That engine also doesn't have fuel injection, distributorless ignition, or an aluminmum block.
(Read: the price comparison is incongruent.)
Quote from: GoCougs on June 30, 2009, 04:38:34 PM
Except with the S/C 5.4L you're getting a warrantable engine designed to last 100,000+ miles. That engine is neither.
*Ahem* "After detailed assembly and dyno testing, you can rest assured that each motor was constructed by hand with the utmost quality and care by Pat Musi, applying 37+ years of big block Chevy experience.
2 year/unlimited mileage warranty."
Quote from: Cobra93 on June 30, 2009, 05:12:36 PM
*Ahem* "After detailed assembly and dyno testing, you can rest assured that each motor was constructed by hand with the utmost quality and care by Pat Musi, applying 37+ years of big block Chevy experience. 2 year/unlimited mileage warranty."
But it was not designed to last 100,000+ miles as was the S/C 5.4L.
Quote from: GoCougs on June 30, 2009, 06:01:22 PM
But it was not designed to last 100,000+ miles as was the S/C 5.4L.
You didn't build it, so what you say it's designed to last for doesn't matter.
My El Camino's new crate engine better last 100,000 miles. That's why I bought it.
Quote from: hotrodalex on June 30, 2009, 07:30:14 PM
You didn't build it, so what you say it's designed to last for doesn't matter.
My El Camino's new crate engine better last 100,000 miles. That's why I bought it.
No, I didn't build it but I can guarantee that that Dart did not invest $250MM+ of engineering (as did Ford and the Modular) into that custom block, and crank and rod set, so yes what I say
does matter.
If your crate engine is a stock virgin two-bolt block or a mildly-built virgin four-bolt block and otherwise wasn't screwed up, 100k is realistic; anything else, it ranges from probably not (moderately-built 0.030" over seasoned four-bolt block) to not a chance (strongly-built 0.060" over seasoned two-bolt block).
I think Soup would enjoy this thread, were he not picking grapes or whatever it is that he's off doing.
Quote from: GoCougs on June 27, 2009, 06:00:51 PM
But in terms of new engine families, i.e., that which the automakers have invested in recently, only two have been pushrod (Hemi an LSx); all others have been OHC.
If you are saying that automakers are not investing in OHV engines save for the hemi and LS line, then I have serious doubts that GM decided to put a couple V6 OHV engines into a brand new car without any real investments into the designs to make them more competative with OHC engines. That would make zero business sense.
(then again, we are talking about GM :lol:)
And, you will have to provide proof for any arguments to the contrary as common sense would dispute your above claims.
Quote from: hounddog on June 30, 2009, 09:19:22 PM
If you are saying that automakers are not investing in OHV engines save for the hemi and LS line, then I have serious doubts that GM decided to put a couple V6 OHV engines into a brand new car without any real investments into the designs to make them more competative with OHC engines. That would make zero business sense.
(then again, we are talking about GM :lol:)
And, you will have to provide proof for any arguments to the contrary as common sense would dispute your above claims.
The 3.5L and 3.9L "High Value" V6 is of the same pushrod 60-deg V6 family as the 2.8L, 3.1L and 3.4L of the '80s and '90s, so I think it very debatable that it be considered all-new as can be the LSx and Hemi.
Further, GM has already stated (and shown) that the engine is being replaced by the "High Feature" 3.6L V6. The engine will essentially come and go with the current generation Impala and Pontiac. It may hang around in a legacy fashion as the base engine on a few cars, but that'll be about it.
Quote from: GoCougs on June 30, 2009, 09:05:35 PM
No, I didn't build it but I can guarantee that that Dart did not invest $250MM+ of engineering (as did Ford and the Modular) into that custom block, and crank and rod set, so yes what I say does matter.
If your crate engine is a stock virgin two-bolt block or a mildly-built virgin four-bolt block and otherwise wasn't screwed up, 100k is realistic; anything else, it ranges from probably not (moderately-built 0.030" over seasoned four-bolt block) to not a chance (strongly-built 0.060" over seasoned two-bolt block).
You're hilarious :thumbsup: You literally don't have a clue what you're talking about yet you soldier on regardless.
Quote from: GoCougs on June 30, 2009, 09:40:16 PM
The 3.5L and 3.9L "High Value" V6 is of the same pushrod 60-deg V6 family as the 2.8L, 3.1L and 3.4L of the '80s and '90s, so I think it very debatable that it be considered all-new as can be the LSx and Hemi.
Further, GM has already stated (and shown) that the engine is being replaced by the "High Feature" 3.6L V6. The engine will essentially come and go with the current generation Impala and Pontiac. It may hang around in a legacy fashion as the base engine on a few cars, but that'll be about it.
I am neither saying that, nor am I disputing that.
But, you did not answer my question regarding companies investing in OHVs.
Quote from: GoCougs on June 30, 2009, 09:40:16 PM
The 3.5L and 3.9L "High Value" V6 is of the same pushrod 60-deg V6 family as the 2.8L, 3.1L and 3.4L of the '80s and '90s, so I think it very debatable that it be considered all-new as can be the LSx and Hemi.
Further, GM has already stated (and shown) that the engine is being replaced by the "High Feature" 3.6L V6. The engine will essentially come and go with the current generation Impala and Pontiac. It may hang around in a legacy fashion as the base engine on a few cars, but that'll be about it.
I must say - the base 3.6/automatic combination that hides in lower-level Commodores (235hp, 4-speed automatic) is quite an underwhelming drivetrain, and even the 261hp/5-speed combination in higher trim levels isn't all that inspiring. The Falcon's I6 is noticeably more refined and torquey, at least until the direct-injection HFV6 variants arrive sometime later this year if speculation is to be believed.
Quote from: Cobra93 on June 30, 2009, 10:09:32 PM
You're hilarious :thumbsup: You literally don't have a clue what you're talking about yet you soldier on regardless.
I don't know how much more that I can add; the stock Chevy small block is a good ~100k motor; absolute so for the two-bolt Mexican (i.e., low nickel) blocks. I've owned and rebuilt both two-bolt and four-bolt SBCs, and otherwise lived that world for some time. A rebuild that lasts more than a 100k is a rarity; the more you build it up and/or the more you over-bore it the shorter life it'll have, and that's provided everything is done correctly (plastigage checked, etc.), which more than a few times it is not.
Quote from: hounddog on June 30, 2009, 10:19:34 PM
I am neither saying that, nor am I disputing that.
But, you did not answer my question regarding companies investing in OHVs.
I'm not sure the question I missed - why they'd invest in pushrod motors if there is no plan to make/keep them competitive? I think they plan/hope to, as in the market the LSx and Hemi play in, there is precious little competition.
Quote from: GoCougs on June 30, 2009, 10:33:00 PM
I'm not sure the question I missed - why they'd invest in pushrod motors if there is no plan to make/keep them competitive? I think they plan/hope to, as in the market the LSx and Hemi play in, there is precious little competition.
I asked if you were saying that GM/others were only investing in new OHV engines, and if so (please refer back to my other post for the question).
I am not picking a fight, to be honest, just wondering what your position is on the investment issue as it pertains to freshening older engines for modern use in new models.
Is this shit settled yet? I need to know which one to buy in the future. Because surely I don't want to buy the wrong motor and have to replace it 10 miles down the road.
It would depend upon what the intended application is.
Quote from: hounddog on June 30, 2009, 10:43:31 PM
It would depend upon what the intended application is.
Getting more than 10 miles down the road. :lol:
I would go with a supercharged hemi making 1300hp in that case. Of course I'm assuming the road is straight and I can just put the pedal to the metal and get 11 miles away in a couple minutes.
Quote from: GoCougs on June 30, 2009, 10:26:01 PM
I don't know how much more that I can add; the stock Chevy small block is a good ~100k motor; absolute so for the two-bolt Mexican (i.e., low nickel) blocks.
Those blocks are preferred for their HIGH nickel content.
Quote from: GoCougs on June 30, 2009, 10:26:01 PMI've owned and rebuilt both two-bolt and four-bolt SBCs, and otherwise lived that world for some time. A rebuild that lasts more than a 100k is a rarity; the more you build it up and/or the more you over-bore it the shorter life it'll have, and that's provided everything is done correctly (plastigage checked, etc.), which more than a few times it is not.
And I've spent 16 years in a racing engine supplier, not only doing the machine work hands-on, but coordinating with customers and designing and specing out the combination that will produce the result they want. Everything from pump gas, hydraulic cam, daily driver 350 horse small blocks to Rodeck block, Brodix head, 420 inch Sprint car engines. I've probably forgotten more than you ever knew about building high performance engines. And, just so you know, NO real engine builders use plastigage. That's for back yard mechanics and lawn mower engine building.
I stay away from the performance market now because it gets tiresome having to constantly re-educate guys like yourself.
Quote from: Cobra93 on July 01, 2009, 08:25:07 AM
Those blocks are preferred for their HIGH nickel content.And I've spent 16 years in a racing engine supplier, not only doing the machine work hands-on, but coordinating with customers and designing and specing out the combination that will produce the result they want. Everything from pump gas, hydraulic cam, daily driver 350 horse small blocks to Rodeck block, Brodix head, 420 inch Sprint car engines. I've probably forgotten more than you ever knew about building high performance engines. And, just so you know, NO real engine builders use plastigage. That's for back yard mechanics and lawn mower engine building.
I stay away from the performance market now because it gets tiresome having to constantly re-educate guys like yourself.
The Mexican blocks are crap. It is the domestic, large journal, 4-bolt, non-400 blocks that are king (in terms of factory blocks), with a slight bent toward the '86+ one-piece rear main seal versions.
If you think I'm wrong, please state why in objective terms. I've never claimed to be an expert in anything, yet I clearly state facts and can be countered and/or challenged.
If HRAlex's crate motor is stock or very mild build, professionally done, on a non-400, 4-bolt block, I think he can expect 100k; anything other than that, from a stouter build, to two-bolt mains, to a 400 block, to a 0.060" over-bore, to gods knows what else, and I don't think he will get 100k.
And I emphasized the use of the term ("plastigage
'd") such that it was a verb, which was to imply that the critical aspects of the build process are
certified, however it may be done.
Quote from: hounddog on June 30, 2009, 10:41:42 PM
I asked if you were saying that GM/others were only investing in new OHV engines, and if so (please refer back to my other post for the question).
I am not picking a fight, to be honest, just wondering what your position is on the investment issue as it pertains to freshening older engines for modern use in new models.
I think we can all agree it's much cheaper to update an older engine than it is to develop an all-new engine, and provided the automaker feels that it can be made competitive enough, I wouldn't blame them at all. At some point, all engines will need to be replaced no matter their valve train; the days of riding an engine for three or four decades as the domestics did are long gone; the market now is just far too competitive.
Quote from: GoCougs on July 01, 2009, 09:44:59 AM
The Mexican blocks are crap.
Then why did you post this?
Quote from: GoCougs on June 30, 2009, 10:26:01 PM
I don't know how much more that I can add; the stock Chevy small block is a good ~100k motor; absolute so for the two-bolt Mexican (i.e., low nickel) blocks.
Quote from: GoCougs on July 01, 2009, 09:44:59 AMIt is the domestic, large journal, 4-bolt, non-400 blocks that are king (in terms of factory blocks), with a slight bent toward the '86+ one-piece rear main seal versions.
If you think I'm wrong, please state why in objective terms. I've never claimed to be an expert in anything, yet I clearly state facts and can be countered and/or challenged.
Actually, two bolt blocks are stronger due to the fact that they do not have two extra holes drilled all the way through the main webbing. This is why engine builders start with a two bolt block and convert it to splayed bolt four bolt caps. I've seen countless race engines rip the main webbing loose at the bottom of the cylinders yet I've never seen one break a main cap, whether two or four bolt.
Quote from: GoCougs on July 01, 2009, 09:44:59 AM
If HRAlex's crate motor is stock or very mild build, professionally done, on a non-400, 4-bolt block, I think he can expect 100k; anything other than that, from a stouter build, to two-bolt mains, to a 400 block, to a 0.060" over-bore, to gods knows what else, and I don't think he will get 100k.
The mileage he can get out of his engine is far more dependant on how well it's tuned and maintained. If it's carbureted, maybe not. If he uses a more modern form of fuel distribution, there's no reason it can't go well beyond 100K. It's no coincidence that engines began lasting much longer after market wide adoption of closed loop fuel injection.
Quote from: GoCougs on July 01, 2009, 09:44:59 AMAnd I emphasized the use of the term ("plastigage'd") such that it was a verb, which was to imply that the critical aspects of the build process are certified, however it may be done.
Good engine builders do their measurements during machining and layout. If you don't trust your measurements and feel the need to use a relatively inaccurate method such as plastigage, you probably shouldn't be building engines.
Quote from: Cobra93 on June 30, 2009, 03:44:02 PM
Since we're going there, how about an LS9?
Interestingly, the LS9 crate engine costs a bit more ($21K) than the 5.4 OHC engine, sure it has a bit more hp but not much of a difference.
http://www.motorauthority.com/gm-to-offer-the-corvette-zr-1s-ls9-as-a-crate-engine.html
Quote from: SVT32V on July 01, 2009, 12:51:30 PM
Interestingly, the LS9 crate engine costs a bit more ($21K) than the 5.4 OHC engine, sure it has a bit more hp but not much of a difference.
http://www.motorauthority.com/gm-to-offer-the-corvette-zr-1s-ls9-as-a-crate-engine.html
It also has a more advanced supercharger, as it uses Eaton's new 4-lobe blower that provides better efficiency, almost as good as a turbo's. That could explain the price difference.
Quote from: hotrodalex on July 01, 2009, 01:08:02 PM
It also has a more advanced supercharger, as it uses Eaton's new 4-lobe blower that provides better efficiency, almost as good as a turbo's. That could explain the price difference.
Same blower as the GT500, its not like you give up a liter and make similar power with a crappy blower, per the provided 5.4 SC link.
"Fully dressed including accessory drive and 2.3L Twin Vortices Series Eaton 4-lobe 160 degree twist rotors supercharger M-6066-SGT"
Quote from: SVT32V on July 01, 2009, 01:43:55 PM
Same blower as the GT500, its not like you give up a liter and make similar power with a crappy blower, per the provided 5.4 SC link.
"Fully dressed including accessory drive and 2.3L Twin Vortices Series Eaton 4-lobe 160 degree twist rotors supercharger M-6066-SGT"
I never said the GT500's blower was be crappy. For some reason I thought it was an earlier version of the ZR1's. Blowers can make the same power and still have different efficiency rates.
And I stand corrected anyway, so it doesn't matter.
Quote from: Cobra93 on July 01, 2009, 10:54:25 AM
Then why did you post this?
I was implying that 100k is not a very long-lived motor.
Quote
Actually, two bolt blocks are stronger due to the fact that they do not have two extra holes drilled all the way through the main webbing. This is why engine builders start with a two bolt block and convert it to splayed bolt four bolt caps. I've seen countless race engines rip the main webbing loose at the bottom of the cylinders yet I've never seen one break a main cap, whether two or four bolt.
Fair enough, though I did not actually state which was stronger, but the stock-for-stock, the 2-bolt block doesn't have the stability for longer life at higher power levels, and the only 4-bolt block that has inherent problems is the 400 SBC.
Quote
The mileage he can get out of his engine is far more dependant on how well it's tuned and maintained. If it's carbureted, maybe not. If he uses a more modern form of fuel distribution, there's no reason it can't go well beyond 100K. It's no coincidence that engines began lasting much longer after market wide adoption of closed loop fuel injection.
I'm sure this is a factor, but it won't supercede other life-affecting factors that I've mentioned previously.
Quote
Good engine builders do their measurements during machining and layout. If you don't trust your measurements and feel the need to use a relatively inaccurate method such as plastigage, you probably shouldn't be building engines.
Again, fair enough, and I think/thought that's exactly what I was implying.
This can't end!
Pushrods > DOHC.
Quote from: 565 on July 27, 2009, 10:52:36 PM
This can't end!
Pushrods > DOHC.
Please let it die!
Quote from: gotta-qik-z28 on July 28, 2009, 12:10:18 AM
Please let it die!
(http://www.neowin.net/forum/fun/thread_wont_die.jpg)
Quote from: 280Z Turbo on July 28, 2009, 12:23:54 AM
(http://www.neowin.net/forum/fun/thread_wont_die.jpg)
:facepalm:
The answer to this thread:
http://www.youtube.com/watch?v=ukwjliJHvyU
No valves!
Quote from: 280Z Turbo on July 28, 2009, 12:54:12 AM
The answer to this thread:
http://www.youtube.com/watch?v=ukwjliJHvyU
No valves!
I love how the trunk pops open at take off. That car needs a good driver. Short wheel base and godly performance is a scary combo.