Race Engine Forum UK

Hi Peter,

I'm going to be running std cam with a Pumaracing big valve head. Head has been skimmed - think the CR will be about 10.5/11:1. I need to measure the combustion chambers and piston recess to confirm this.

The squish height on your engine seems very small - is this important to geting good power and is it feasible to use such a small squish on an engine running std ignition? Does the tight squish height reduce detonation as long as the CR is sensible?

yes, yes and yes! I thought I posted a graph with two ignitions curves earlier today. Maybe I just previewed it! I'll post it again tomorrow.

Here's a graph of the std. curve and the one I posted earlier.