I will get some pics up, sorry about the bump, didn't know. the head still has standard valves in it as far as i can tell, i don't know who has done the flowing of the head, will post pics soon

Here are the cylindrical envelopes around the combustion chamber, once you machine/surface grind past those; (so your cylinder face is uniform with the platform immediately around the combustion chamber) you end up with a pretty nice format.

The H75 does not have a favorable combustion chamber (but there are worse heads) when up against comparison to the H89 and GX heads, however, once the face of the H75 head is machined and the cylindrical dish (surrounding and merging with the combustion chamber) is no longer existent you get a very nice combustion chamber equivalent or similar in appearance to the H89 and GX heads. The problem is the reduction in the combustion chamber may put your compression ratio at a level where you need high(er) octane fuel but this is also dependent on rest of the engines configuration- I did the calculations once but I cannot find them. Can do them again if you need (using the specs of my motor as a candidate for the head).

The H75 has bigger valves in stock form compared to a GX head in stock form.

I recently saw a H75 head off a race engine and it was one of the best ones I had seen, in terms of modifications. I wish I had bought it now as would heaved served better than the big-port head that I have now.

So I guess if the head hasn't been ported to all buggery and is still around-about stock size then sure it can work just as well.

Maybe upload some pictures and provide some specifications (springs, valves sizes, chamber cc's etc etc) and we can offer a more specific opinion.

The A12 GX head is 83HP in stock form ... on an A12
H89 head is 80HP in stock form ... on an A14
H75 heas was 75 HP in stock form

Quote:
How much power are you aiming for?

Bump after a few days, not a few hours...

Just how worked is the head? and has it been done by somone with experience or a kid with die grinder? if its done right you might similar gains to the stock GX or H89... if not, you mine as well go with the right parts the first time.

bump

i've started out with the branch and freeflow, did the weber carb coversion, not enough power yet, so i got hold of an already ported end flowed h75 head, would these with modification work as well as the gx or h89 head as i would like to use the h75 head because it's already worked? i will be getting a cam cut before fitting the head