Originally Posted by Chip-3Door
Originally Posted by Mike Rainbird
You have to realise that the geometry (bore and stroke) of different engines means that some will take an increase in compression no problem and there will be good gains to have by this (Eg. Evos), where as others, all this causes is major heat related issues requiring severly retarded ignition (Cossies).
So saying high compression is good or bad is a misnomer, as it is TOTALLY reliant to it's particular engine configuration application.
Mike, the OP was referring to zetec motors in the states and over here.
That makes it even worse, as they rate their fuel differently to us as well, so you have to be careful making direct comparisons to the Yanks.
Without checking, I don't know the bore and stroke of the Zetecs, so couldn't comment on whether these engines (like the Evos) lend themselves to high compression?