joffy: I ment to put Higher comp in my first post.


The original engine with this head showed that the valves had touched and marked the pistons. So it would seem reasonable that head depths were physically dicated by a mechanical interferance issue which on a standard engine with standard pistons would be valve clearance.
As well as the impact of higher CR which will be some what offset by the material removed from the valve cut outs and my current setup has valve cut outs.

I have seen the thread about valve seats, however, is this big power engines running high lift CAMS? double valve springs etc, as that would put far more material stress on the seat.


Graham: Head gasket looked OK mate, but i don't want to put that head back on (always leaked water around the exhaust ports), so i'd like to use this other one.