Cam specs for '62 Corvette Fulie

[JeffKeryk]

I have been asked about the cam specs for a 1962 Corvette 327 FI, 360 HP. My BIL is adjusting the lash on his restored '62. He bought the engine (period correct) from a builder. I don't know that much about the early cars... My understanding is the Duntov 097 cam was used in performance solid lifter 1962 Corvettes. I think it was used from '57 until '63; after that the famous 30-30 radical cam was used. The 097 lash specs should be .008 and .018 hot. If you have knowledge regarding a different cam, please chime in. I really think the timing cover should be removed and check for numbers. I asked him to measure I/O valve lift and I can compare that to the specs I know of. Thanks in advance.

 

[Shannow]

Hmmm...checked my libreary...I had a book on the Chev fuellies...appears to have been borrowed over the last 20+ years...

 

[jhs914]

The legendary Duntov SBC solid lifter cam was referred to as the 30-30 cam because that was the cold valve lash spec, .30" on both intake and exhaust valves. Now this is coming from the memory banks of a 72 year old former hot rodder, so take it with a grain of salt.

 

[cknight49090]

According to a book I have SBC performance the pre 64 vette had cam # 3736097 mechanical lash .012/.018.

 

[JeffKeryk]

Originally Posted by cknight49090

According to a book I have SBC performance the pre 64 vette had cam # 3736097 mechanical lash .012/.018.

Yes, that's the Duntov 097. I believe the intake lash is .008". I also think this is what is in his car.

 

[JeffKeryk]

Originally Posted by jhs914

The legendary Duntov SBC solid lifter cam was referred to as the 30-30 cam because that was the cold valve lash spec, .30" on both intake and exhaust valves. Now this is coming from the memory banks of a 72 year old former hot rodder, so take it with a grain of salt.

Yes, the nickname was from the I/O settings. People also Mickey Moused around with the settings.

 

[ARCOgraphite]

Remember the rule better loose than too tight. especially the exhaust. Better check double that .008" I number. We could run Street strip cams a bit tighter on the intake for track days, This is a Vintage, car I would err on the side of conservatism. This is a very mild cam. You should be fine at 0.01: cold.. Also see where they are at. I would check and record three first. And Re- torque the head bolts while you are in there. - Ken

 

[JeffKeryk]

Originally Posted by ARCOgraphite

Remember the rule better loose than too tight. especially the exhaust. Better check double that .008" I number. We could run Street strip cams a bit tighter on the intake for track days, This is a Vintage, car I would err on the side of conservatism. This is a very mild cam. You should be fine at 0.01: cold.. Also see where they are at. I would check and record three first. And Re- torque the head bolts while you are in there. - Ken

Good advice. The valves are already loose; too late. I asked him to measure the lift at the valve with the clearance set to 097 specs. If the lift matches the 097 valve lift specs, I think I can call it good. Otherwise... He has a ton of $$ and years into this car. He found a period correct block and Mechanical FI Unit. You are so right; he doesn't wanna get this wrong. Personally, I would pull the timing cover and look for ID numbers. While he believes it is the stock reproduction cam for that engine, it could be anything. I agree .010 cold Intake is a safe setting. This is a show and fun car; no beating.

 

[Randy_R]

I found this. Looks like .012 and .018 are correct for this cam. https://www.enginelabs.com/engine-tech/cam-valvetrain/duntov-small-block-camshaft/

 

[JeffKeryk]

I asked my BIL Mark to measure the intake and exhaust lift at the valve as best as he could. He came up with .468" intake and just a taste more on the exhaust valve. I used .468" divided by 1.37 rocker ratio to come up with .342 lobe lift. The 097 cam is generally thought to be .395" and .399" I/O. I am calling this the 097 cam for now. I suggested .012" and .018" lash. My Motor Manual lists .008" for the intake, but my research says this is more for the weekend warrior who wanted a little more duration... I also pinged my friend Lars Grimsrud. Yes, I know I am name dropping... He also cautioned me on the tight valve numbers. Thanks for all your help.