Corvette project car

[Eye of the Tiger]

I can see it. Just weld some more metal onto the tip if it is too low.

[280Z Turbo]

Found another lobe gone. They are both exhaust valves. They were probably getting about 0.090" of lift instead of the usual 0.400" or so.

I don't know why only 2 are bad. It's also making me think about bending over and paying $600 for a roller cam. All of the talk of ZDDP and flat tappet cam break in procedures is scaring me.

[FlatBlackCaddy]

LS3?

[FlatBlackCaddy]

I like my classics with a bit of modern "updates"



Makes me want an old corvette. Just need to win the lottery for something that nice.

http://www.corvetteforum.com/forums/c1s-and-c2s-for-sale-wanted/3530071-fs-1963-split-window-restomod.html

[280Z Turbo]

LS3?

Yup. It just drops right the fuck in. And good thing they only cost $500. 

[FlatBlackCaddy]

Yup. It just drops right the fuck in. And good thing they only cost $500. 

It's a moneypit, might as well put the wheelbarrow away and rent a dump truck and fill her up.

[GoCougs]

Cam lobe is gone

Yup. Very common. That was probably your #1 reason for power loss. And even the lobes that aren't wiped are probably a wreck too.

[GoCougs]

Found another lobe gone. They are both exhaust valves. They were probably getting about 0.090" of lift instead of the usual 0.400" or so.

I don't know why only 2 are bad. It's also making me think about bending over and paying $600 for a roller cam. All of the talk of ZDDP and flat tappet cam break in procedures is scaring me.

Just B10 life really - not all bearings go bad at the same time and flat tappet cams wear relatively quickly. I've replaced a number of cams with 100-120k that had lobes wiped.

I wouldn't worry about cam break-in. It's pretty easy. Make sure there is cam lube on then run it at ~3,000 rpm for ~30 minutes upon start up.

Cam life won't be an issue on a rebuild for a hot rod - you'll likely never get close to 100k miles.

This engine was so shot that a basic 9:1 rebuild with an RV cam will feel like big block. I'd skip the roller cam for now.

[hotrodalex]

Cam break-in is pretty simple like Cougs said.

[280Z Turbo]

Another thing I can't figure out is what the hell does leaded gas have to do with exhaust valve seats? I get that there must have been lead in the exhaust gases, but how would a significant amount of lead get stuck behind the valve enough to cushion it as it closes?

[FoMoJo]

Another thing I can't figure out is what the hell does leaded gas have to do with exhaust valve seats? I get that there must have been lead in the exhaust gases, but how would a significant amount of lead get stuck behind the valve enough to cushion it as it closes?

As a couple of tank fulls of leaded gas can contaminate a catalytic converter, it would suggest that there is still a good amount of unburned lead in exhaust gases.

[GoCougs]

Another thing I can't figure out is what the hell does leaded gas have to do with exhaust valve seats? I get that there must have been lead in the exhaust gases, but how would a significant amount of lead get stuck behind the valve enough to cushion it as it closes?

Don't need much plus the pressure/flow/turbulence of the exhaust cycle will be pretty high.

[280Z Turbo]

Found a '74 frame locally. Would need some modifications to work with a '63 body, but I like $800 + some fab work better than $5800.

[Secret Chimp]

Another thing I can't figure out is what the hell does leaded gas have to do with exhaust valve seats? I get that there must have been lead in the exhaust gases, but how would a significant amount of lead get stuck behind the valve enough to cushion it as it closes?

All I know is the tops of my valve stems were all perfectly even when I last had the rockers off and I doubt my car was religiously run with lead additive. It only matters with big constant loads.

[280Z Turbo]

Looking a the Comp Cams XE262H and Lunati Voodoo 60102. They look like similar grinds.

I am leaning towards the Comp cam now because it has the same intake lift as the Lunati, but less on exhaust. With full length headers and 2.5" chambered dual exhaust, there's not much restriction anyway. If I still had stock manifolds, 2" exhaust and quiet mufflers, I could see how it might help.

http://www.lunatipower.com/CamSpecCard.aspx?partNumber=60102
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=85&sb=2

[S204STi]

Looks good man.

[GoCougs]

Those cams have a fair degree of difference. Seems like a lot of lift for not a whole lot of duration. Will you get advantage with 1.88/1.50 heads and relatively small displacement? Thing is cam choice becomes a bit more sensitive with M/T as there is no converter to stall up against should the cam be a bit aggressive. Of those two I'd choose the Comp Cams, and betcha the car drives/performs better with stock manifolds, 2" exhaust and quiet mufflers.

[280Z Turbo]

Those cams have a fair degree of difference. Seems like a lot of lift for not a whole lot of duration. Will you get advantage with 1.88/1.50 heads and relatively small displacement? Thing is cam choice becomes a bit more sensitive with M/T as there is no converter to stall up against should the cam be a bit aggressive. Of those two I'd choose the Comp Cams, and betcha the car drives/performs better with stock manifolds, 2" exhaust and quiet mufflers.

I'd bet it drives better if we sell it and replace it with a V6 Camry.

[Eye of the Tiger]

Wow. No. Dont be Cougstupid. Put modestly sized long tube headers on it.

[280Z Turbo]

Wow. No. Dont be Cougstupid. Put modestly sized long tube headers on it.

It already has them. It's always had them since my dad got it.

[280Z Turbo]

On another note, I'm not sure I should trust the engine build shop's advice. They suggested a lumpy cam with over .500 of lift. Not gonna work with double hump heads. LOL

He also thought 10.5:1 compression would be good. I think stock 10:1 compression is fine (what its always had) but 10.5 is pushing it.

[GoCougs]

I'd bet it drives better if we sell it and replace it with a V6 Camry.

What does this even mean. Meh, good luck, kinda sounds like you're gonna need it, but in the least it's fairly hard to really screw it up and relatively easy to unscrew it.

[280Z Turbo]

kinda sounds like you're gonna need it

[280Z Turbo]

http://www.superchevy.com/how-to/49178-headers-power-increase/

[Eye of the Tiger]

http://www.superchevy.com/how-to/49178-headers-power-increase/

"The header manufacturers sponsered that article, so it is a government conspiracy." -GoPubes

[280Z Turbo]

I didn't think the OEM superiority shtick would be applied to a cheap grocery-getter engine from 1965.

[hotrodalex]

Grocery getter?

[280Z Turbo]

Grocery getter?

1965 Impala 327 w/Powerglide engine

AKA the 275 hp L30

[Soup DeVille]

I didn't think the OEM superiority shtick would be applied to a cheap grocery-getter engine from 1965.

Its been applied to my car, why not yours?

[280Z Turbo]

What kind of cam do you have that allows you to make peak power at only 3000 rpm? Is it like .250" of lift or something?