Cam questions

[Joshpow]

I want a rough idle for my 302. What would be a good duration and lift to get a jarring idle? Also, what would be the biggest to use without changing the rockers, valve pushrods, etc? Thanks for any input.

[green1970]

i had the same dilema with my 302. Finally found a cam, but they do not make it any more. It was a crane powermax, with 218 degrees of duration at .050, and .484 lift. The Crane energizer has the same lift but the duration is only 214 or 216. mine is bored .030 over, with an edelbrock performer intake with the matching carburetor (600 cfm). i have the stock exhaust manifolds with 2 1/2 in. exhaust with flowmaster 40 series mufflers and the exhaust is turned down right behing the axle. It has a rough idle and a slight lope to the exhaust. i love it!

[Joshpow]

cool thanks. I may not need as extreme as I thought.

[Physics Guy]

I worked my way through college grinding cams at a regrind shop. If you can find one, tell them what you are looking to do, and they probably can build what you are looking for. If you are only changing the cam and not doing anything to the heads, you might be best served by keeping the lift stock and adding to the duration and overlap. If you are rebuilding the heads, or they are known to be good, then go ahead and wick up the lift a bit.

Reed cams have quite a few profiles aimed at oval track "lift rule" use. These profiles might be just the ticket.

I run 254@.050 in my oval track car, with about .575 valve lift. It's choppy to say the least, and 12.5 to 1 compression gives it that "cackle"