1964 Honda SM600

[Morris Minor]

I know Leno repeats himself in these videos but it's worth enduring just to listen to the sound this thing makes (9,500rpm red line). I remember these because neighbors of my parents where I grew up had his & her Honda S600s, husband and wife. (he'd made his money as the inventor of the UHT process for milk).
http://youtu.be/Qdck07wTRXo

[FoMoJo]

Interesting little car.  I remember reading about them when they first came out, but never saw one.  It always puzzled me a bit about the chain drive.  It seemed a bit over-complicated for the benefit.

[GoCougs]

Seems a few reasons for the rear suspension. It's gets the (heavy) diff closer to the center of the car - better weight distribution and a shorter drive shaft (important for 9,500 rpm red line). It also affords independent suspension and constant camber articulation at that (but not sure if latter is an advantage).

[hotrodalex]

I'd still like an oil pressure gauge.

[68_427]

Freaking love this car.

[Eye of the Tiger]

Its all about the Flowmasters

[Rupert]

Why don't you need an oil pressure gauge with a roller bearing crankshaft?

[Eye of the Tiger]

Why don't you need an oil pressure gauge with a roller bearing crankshaft?

Cuz the bearings dont need to be pressurized in order to keep the metals apart. Shit just rolls!

[FoMoJo]

Why don't you need an oil pressure gauge with a roller bearing crankshaft?

When bearings wear the pressure drops due to lack of resistance to the flow of oil.  With needle bearings, the resistance isn't there...I think .

[Rupert]

Doesn't oil pressure matter for other parts? Like those in the head?

[Eye of the Tiger]

Doesn't oil pressure matter for other parts? Like those in the head?

Solid lifters, mang.

[FoMoJo]

Doesn't oil pressure matter for other parts? Like those in the head?

It flows there.  I'm wondering what kind of pressure it needs to squirt up under the piston.

[GoCougs]

Doesn't oil pressure matter for other parts? Like those in the head?

Yes. That "it has roller bearings" reasoning for not having an oil pressure gauge was nonsense. Roller bearings need oil too, as will the cam, wrist pins, valve train, and rings, and there has to be a good amount of pressure for it to circulate. And really, by and large oil pressure gauges are a big meh. Not only can pressure vary widely for a properly running engine, pressure is not the be-all and end-all - oil volume counts too and that is not directly correlated to pressure (good pressure but low flow = starved bearings all the same). By the time the pressure drops due to a problem the engine is already toast. I mean, you might (a BIG might) be able to limit damage by seeing a pressure drop and shutting it down, but that's a big "might."

I will say a roller bearing crank is all sorts of mega cool though.

[Rupert]

Maybe I've been self-mislead, but I've always thought of oil pressure as, is oil moving?

[Eye of the Tiger]

Maybe I've been self-mislead, but I've always thought of oil pressure as, is oil moving?

The movement of volume comes from the pump, but the pressure is created by forcing that volume through controlled orfices and the clearances of oil lubricated plain sliding bearings (not roller bearings). Aren't you a hydrologist or something? So worn bearings = bigger clearance = larger office = lower oil pressure.

[Rupert]

Right, but how else do you know if the right volume is being moved? You can also slow the movement of volume through the smaller orifices to decrease pressure, yes?

Hydrologist, not hydraulicist.

[FoMoJo]

The movement of volume comes from the pump, but the pressure is created by forcing that volume through controlled orfices and the clearances of oil lubricated plain sliding bearings (not roller bearings). Aren't you a hydrologist or something? So worn bearings = bigger clearance = larger office = lower oil pressure.

Yes, a better explanation. Worn bearings, crank journals, will lower oil pressure.  Even one worn journal bearing will lower the pressure impacting flow through the bearings that aren't worn. 

[Rupert]

Oh, and yes, of course that makes sense.

[Eye of the Tiger]

Right, but how else do you know if the right volume is being moved? You can also slow the movement of volume through the smaller orifices to decrease pressure, yes?

Hydrologist, not hydraulicist.

It is designed into the system. Nobody has an oil volume gauge because the volume is basically fixed to engine speed as long as the oil pump works. Pressure will vary with wear, temperature, and volume, so someone decided pressure was important to know.

[hotrodalex]

Oil pressure gauge also works as a temperature gauge. And knowing if you took out the oil pan on a large rock.

[Rupert]

Seems like things like a busted oil pump or an increasingly large leak would be good to know ASAP, though.

I mean, whatever, most cars now just have a perfectly functional idiot light.

[GoCougs]

Maybe I've been self-mislead, but I've always thought of oil pressure as, is oil moving?

Yes, and that's basically all an oil gauge is good for  - oil is moving. On a perfectly fine engine, oil pressure can vary widely based on temperature, viscosity, oil age and RPM - so unless you've oil pressure memorized for a given combo of these factors (I imagine some do, as in race car guys), pressure in and of itself doesn't mean much (unless of course it's ~0 psi). So, it's basically oil pressure gauge itself is an idiot light.

[Soup DeVille]

Maybe I've been self-mislead, but I've always thought of oil pressure as, is oil moving?

Not necessarily; but it does imply the oil pump is working and there is oil. A blocked oil passage can still starve out any one part.

And even if oil is moving where the pressure gauge is; what's to say it's moving everywhere else?

[Eye of the Tiger]

Not necessarily; but it does imply the oil pump is working and there is oil. A blocked oil passage can still starve out any one part.

And even if oil is moving where the pressure gauge is; what's to say it's moving everywhere else?

The fact that your engine is still running is what says it.

[Soup DeVille]

The fact that your engine is still running is what says it.

Yes, but the intent of the oil pressure gauge is to let you know something's amiss before the engine seizes.

[Tave]

my car is like my own personal universe
she's my drug and it only takes twelve bucks to fill 'er up
but in my galaxy there ain't no room for Earth
so I'm leavin it cuz I can feel the oil pressure building up
turning over the ignition of my solar system
check the gauges, push in the tape, put my foot on the brake
shift existence, light my cigarette
and take it state to state until I crash into my fate

[FoMoJo]

Yes, but the intent of the oil pressure gauge is to let you know something's amiss before the engine seizes.

After the engine seized in my '57 Studebaker, lost a frost plug and the coolant drained, when it cooled off and contracted to the point that I could start it, the oil pressure was almost non-existent because of sudden bearing wear.  Of course, all the knocking let me know something was amiss as well.

[Rupert]

Not necessarily; but it does imply the oil pump is working and there is oil. A blocked oil passage can still starve out any one part.

And even if oil is moving where the pressure gauge is; what's to say it's moving everywhere else?

Of course.

[Laconian]

What a sound. Holy shit.

[Rupert]

Makes me want an S2000 even more.