Compression Ratio

Hi everyone, just wondering what sort of compression psi I could expect on a 1.4 running about 10.2:1 with 270deg rally cams?

And what about on a 1.4 running about 10.8:1 with 270deg rally cams?

Would really appreciate any help.

Having researched on the forums, to my understanding, a guide figure would be:

For the 10.2:1 engine, I should expect around 195psi on standard cams, and around 170psi on rally cams.
For the 10.8:1 engine, I should expect around 215psi on standard cams, and around 190psi on rally cams.
From my understanding, a completely standard healthy 1.4 should be 180psi.

Does this all seem reasonable? Many thanks.
 
Last edited:
Actually it seems, my cg13 on a 1mm head skim (about 10.7 cr, probably less) measured at 195psi

Enviado do meu MI 8 através do Tapatalk
 
Top