Quote Originally Posted by Gusaroo
Dumb question: Can you calculate your compression ratio by doing a compression test? My buddy tells me you can't do it...
I'll have to disagree with Denny. I all depends on the cam in the motor and the intake closing point ground into the intake lobe. Compression does not start until the intake valve closes, so you could have a 10:1 motor with a very short cam in it that would test out at, for instance, 200 lbs. Change the cam to a very long duration unit with a delayed intake closing point and you could read 120 lbs. I'm not being scientific on these figures, just trying to make a point.