Overlap has ABSOLUTELY no effect on dynamic compression ratio. Dynamic CR is only effected by the timing of the intake valve closing. The later the Int valve closes the farther up the bore the piston is, therefore the less cylinder pressure the engine builds.

CFI-EFI said it correctly except intake valve closing doesn't have the greatest effect on Dynamic CR, it is the only thing that effects Dynamic CR.

I wanted to leave myself a little "wiggle" room. There is an abundance of nits out there waiting to be picked.

RACE ON!!!

your right and someone could have nit picked me by saying that static compression is a large factor also. Which it is. Here is a calculator for Dynamic CR, as you will see they only additional factor above what you put in for static CR is intake valve close timing.

http://www.smokemup.com/auto_math/dy...sion_ratio.php