E31 vs. P90 on a 280z Short Block

[RickX]

I have a E-31 Head that I would like to put on an F-54 block.

With Manley SS valves, can I get this head to flow as well as a P-90 head?

Usually mods, cam, headers, and Mallory. Nothing too radical or too fast.

Rick

[2ManyZs]

If you put the 280 valves in the E-31, and do a little port matching on the head, intake and exhaust (header?) it should come fairly close to the P-90. And you'll end up with a better compression ratio to boot(if neither head has been shaved) because of the smaller chamber in the E-31. If you have flat top pistons in the F-54, you should end up around 9.5:1 with the compression depending on machine work done to the block and head.

[ZmeFly]

though the P90 will flow a little better, then main thing of it is with the P90 you will have to shave about .080 off the head, then of course shim the cam towers to maintian valve train geometry

[Mr Camouflage]

Instead of shimming the cam towers, cant you put an adjustable cam sprocket on it?

I know its more expensive and you might not be able to get one for the L engine, but it would have the same effect wouldnt it.

[RickX]

Iwas always told ot to unbolt the cam towers, i.e. loses alignment?

That was the '70's and Racer Brown notes and quotes.

Adjusting the timing will not take-up slack in the chain tension. The tensioner does that, and back thena nother reason not to mill the head excessively.

Could have changed, been out of the loop for almost 3 decades.

Rick

[hf240z]

Originally posted by ZmeFly

though the P90 will flow a little better, then main thing of it is with the P90 you will have to shave about .080 off the head, then of course shim the cam towers to maintian valve train geometry

shaving for .080 , does .080 ..is that mm? or the machinist will already know that.