6 replies to this topic

[cheesebadger]

Just putting it out there, but I have been thinking about charge/flow robbing in the standard head...

Has anyone ever considered using the current inlet port (siamesed) as exhaust ports, and using the 3 exhaust as inlets?
This would remove the inlet charge robbing as the inner cylinders would now be siamesed which is ok. It would require new camshaft, inlet & exhaust manifold, plus a completely different types of combustion chamber work.

Any thoughts, or am I being completely stupid...

Thanks, Rich

[Stiggytoo]

Very interesting, I'd like to see peoples opinions on this but I don't think it would be worth the hassle. 

[ACDodd]

One big problem. Intake Valve area!

AC

[nicklouse]

It has been done years ago. BUT when running a supercharger where the above issue is reduced.

[cheesebadger]

Would it not be possible to use a non modified head with a small inlet and max out the size of the exhaust? I haven't even done any porting myself, so not sure how possible/sensible that is...

I have got a couple of superchargers that I was thinking of using with this idea to reduce the effect of a small inlet port/valve, as you have already said, thanks. Have you got anymore info on when this was done before?

[Spider]

It has been done years ago. BUT when running a supercharger where the above issue is reduced.

 

Yeah, I do recall that, I think it was Gorden Allen or the Mashall Brothers or one of those tuners from the late 60's. They perservered with it for a while before giving up on it. None the less, it was thinking outside the square.

[nicklouse]

I came apon this info quite late. It was in 1994/5 when I picked up the GTM shell as the old owner used to do a bit of raving in the 60s. Seemed to be popular in the Holme valley. I seem to recall Imps being mentioned as being the main problem and thus was a solution until (was it the Marshalls put the imp block on the Mini gearbox?) other solutions were found for the class rules.