[acannell]

this is a 2.5 turbo common block

both the head and the block have been surfaced. lets say .010" each.

the pistons are oversize cast mahle, 0.030"

anyone know how i can figure out my new compression ratio?

 

[speeduphoria]

a good guess from my calculator would be .3-4 increase in CR, thats assuming that the dish volume and piston height are the same on all the Mahle pistons(std and overbore)

 

[acannell]

thanks! im thinking a thicker head gasket or shim would be a good idea.

 

[ol"blue]

Compression ratio is figured out by= (cylinder + chamber volume) divided by chamber volume. That's the formula in Mopar's 2.2, 2.5 FWD Performance manual- chapter 13 Racing formula's. That said, you'll have around 8.3 w/o the shim.

 

[Juggy]

MP headgaskets are thicker than stock...I cant remmeber exact #s but .030" sounds about right? someone could prolly correct this if im wrong