PMSL, here i am

Roughly speaking, if you bought a set of 8.2:1 CR pistons for a 16v zetec, assuming the combustion chamber volume of the focus zetec head is similar / the same as the mondeo zetec head.....

Then i think that would give approx 7.3:1 CR if the zetec head was swapped for the CVH head.

This is roughly speaking - as i said above, im going on the presumption that the heads are similar between mondeo and focus.... anyone know?