hey guys will a a14/a15 head fit a standard a12 motor for more get up n go?

http://cgi.ebay.com.au/ws/eBayISAPI.d ... geName=ADME:X:RTQ:AU:1123

Are you going to buy that one? That is a lot of money, but the head is NOS.

Yes H75 is oval port with bigger valves, stronger valve springs and a better shaped combustion chamber.

It can be machined down for even better performance but that is up to you.

my goal is to reach 100hp im just not sure if this would be a direct bolt on ?

Mmmm Bit pricey. For that sort of money you could do alot better

It still needs valves ,springs ,retainers and rocker gear too so thats another 200 odd youll need to spend

H75 is not a great head, it is open chamber. A standard H89 head (closed chamber) would be better. Both have the same compression ratio, but open chamber results in less emisssions, and closed chamber results in more HP.

If your goal is a 100HP engine (which is difficult to achieve with only 1.2 liters) You should use a large port head. There are two: A12 GX head or Nissan Competition head. The Comp head uses the GX casting but has larger A14-size valves. You can always fit the larger valves to a GX head.

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That's true but the H75 is just as good as the H89 once you have decked the head past that large open cylinder volume you can see surrounding most of the combustion chamber.

You won't make 100hp with a NA A12 unless you have at least 5 grand to spend and access to methanol (and a really good A-series builder at that). The A12 I had saw a little over 100hp ATW running twin 45 DCOE's a very big ported big valved GX head and a fairly rich dose of methanol. It was tuned back to 95hp for reliability.

Best to throw $1500 on a nice boosted setup and hope for the best.

A14 or A15 with GX head can make 100HP with the right intake, carbs, cam, exhaust and ignition.

Yes turbo would be the cheapest way.

+1 for A14/15.

Chris was that the motor that was in your thou ? Did it have webers before solexs ?

Boosted A15 +1