Hi everybody,
I'm trying to determine how big the inlet and exhaust ports need to be to flow a certain CFM for a given valve size. Obviously for A-series heads.

I'm after some real head flow data. Dattoman's website shows the results from the flow bench when his head was ported. I was hoping to find some others to get a good spread of port sizes v's cfm. Can anyone help me out here???

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Here you go..

how much did you port?Quote:

how much did you port?

Yeah Rally1200, what are the port sizes that achieved this flow?? Thats if you don't mind telling us?

Also, was the "original" flow data an absolute stock-standard oval port head??

The head was an oval port A14 with 37mm inlet and 30mm exhaust it had been ported by someone who just made the first part of the port bigger but had not done much work around the back of the valve.

So it was flowed like that then he ported it some more and retested.

i still have this head if you need some measurements.

Well, if its not too much trouble, I would love to know what size the ports are at the manifold. I'm trying to relate flow rates to port sizes.

did you use an A14 head? Arent they the H72? I thought they were the really puss open chamber heads. I took an A14 (H72) head in to be shaved one time, and the guy said "mate you are wasting your time". "This head has a bullshit chamber, and will never go any good".

Yep, I got one of 'those' heads in me shed. I was going to use it for practicing porting and chamber working. They are useless for high compression use. Its a shame datsun engineers didn't opt for a lower piston instead of cutting up the head like that!!