i have a 204/214duration, .422/.444 lift cam right now. i want to go with a comp XE 268. it has aout 218/224 duration(if i can remember, and about .462/.469 lift. i don't have any flat spots off the bottom but i want it to pull harder in the middle. its goning into a 283 so i shouldn't need too much cam. do you think i will lose much off the bottom with the comp cam? i'l be happy if it picks up at about 1500 or so.

 

The 268XE cam has a 477/480 lift that I'm positive of, as far as the duration, I'm not sure.

Sure you're not looking at the specs for the 262xe?

 

Viper,

You really don't have any "stump-ripping-outing" torque on the bottom end with a 283 anyway - it's all in the upper RPMs. Don't try to fight the tendency of the crankshaft with a cam that isn't complimentary. The extra lift can probably help in the middle- and upper-RPM ranges, but that engine is going to like a lot of duration as well to support its appetite for higher RPM operation.

 

I would shoot for something with intake duration somewhere between the 204 degrees of your current cam and the 218 degrees of the one you're considering. Maybe 208 to 212.

I'm running 218/218 (@0.050") on a 60-over 283 and it wants to rev the bag off, these short-stroke motors are pretty sensitive to the intake duration.