Originally Posted by
jimhc
I'm looking what CR should be for 400 - 450bhp. Standard 4x4 pistons .25 or bore valve cut outs. Bd10 exhaust and bd14 inlet
I am not sure if there is an exact science to work it out but 7.4 to 7.8 seems to be what most big power engines have. Are you building the engine yourself or having it done by a Cosworth specialist?