Compression in itself doesn't necessarily give you more power, in fact if you build a overly high comp motor without a proper cam choice you can end up loosing power by having a knock limited motor, fuel used Wont support the excessive cylinder pressure and high dynamic compression ratio. The way I see it is compression ratio should be used to raise your static compression ratio up to the point that makes you have a correct dynamic compression ratio for your cam choice.

Everyone knows what static comp is, your piston travels x far and displaced x amount of cc vs the amount of cc left in the cylinder head

the dimmed down version of what dynamic comp is is basically that your dynamic comp ratio is the same thing but doesn't start until the last intake valve closes.

Yes intake valve remain open for a brief period as the piston travels upwards on the compression stroke, they stay open longer with higher duration cams, hence where over camming something comes into play (one example is when you have a low static compression engine and induce large duration cams thus dropping your dynamic comp ratio to low and loosing cylinder pressure and power in turn)


the engine needs to operate harmoniously so you can't just throw some ctr pistons in a otherwise stock ls vtak and think sweet it's 3 points higher comp should make 12% more powa

Also whites on the porcelain of the plug is common, usually means the motor was running good, people commonly mistake white porcelain for oh **** it's too lean, the wot afr is read off the deepest groove in the plug that you can't really see without cutting the plug apart or a light or some ****. Carbon build up is common for a used motor too especially if it wasn't railed on regularly.