Quote:
Originally Posted by MikeB
Compression ratio has a LOT to do with camshaft selection! That's because more duration means the intake valve closes later on the compression stroke. That's why the 1960s GM high performance engines had 11.0:1 compression or more. That's why cam companies' descriptions of their cams will say something like, "likes 10:1 compression" or "works well with 8.5-9:1 compression.
Too little cylinder pressure will reduce torque and make for "soggy" performance at lower RPM. You also need good heads to work with a bigger cam, and the 290hp engine certainly doesn't have them.
Modern cams like the Lunati Voodoo series have less seat-to-seat duration for a given amount of duration @ .050" tappet lift. So they will bleed off less cylinder pressure than a 70s technology GM cam. I'd say the smallest Voodoo cam (#60100) would work great with a 260hp or 290hp crate engine -- certainly MUCH better than the 290hp cam.
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Yes the timing events will bleed off cylinder pressure low cylinder pressure will make the engine feel weak like you said but thats why you dont put a 40yr old grind in a engine today.
I know it sounds crazy and I thought the same thing for a very long time until recently after a conversation with a very intelligent camshaft designer. Let me ask you this, what is the job of the camshaft?