ph1/ph2 engine differences

[rickyquicky]

Have recently bought a phase 1 172 to turn into a track-only toy.

After reading up on them, it seems that the phase 1 have a 'better' cylinder head with larger exhaust ports.

If this is the case why do they not produce MORE peak power? Or there any other differences between phase 1 and 2 engines?

 

[Russ_16v]

Best thing to do is use the search function mate, there have been loads of threads on the subject, but as a rule the Ph1's do tend to produce a few more bhp than the ph2's in my experience (excluding the Cups, as the better matched inlets (plus maybe a better pic of engine) seem to give the cups an advantage) but bear in mind there are so many variables from cam timing, inlet differences, cam timing etc etc - the truth of the matter is there would always only be a few bhp between them anyway.

larger exhaust ports just on their own will not give a big increase over any other model - the time when it makes a difference is when you start tuning, and it makes more sense to use a Ph1 head as it saves having to modify a Ph2 version.