hey guys im doing a g23 motor and i wanted to know what compression would my engine be if i used k20 12.5:1 compression pistons i know its 12.5:1 in a k20 combustion chamber but idk if that applies to the g23 combustion chamber. ohh and i have flat faced valves please guys all your help is appreciated.

 

stock K20A3 (base) with F23 block/crank and F22/H22 head gets you about 11.0:1 static.

you'll need to insert the dome volume into a calculator like this one and account for the flat face valves.

it's gonna be high i'm guessing.