Posted October 31, 200321 yr comment_55426 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 Link to comment https://www.classiczcars.com/forums/topic/8661-e31-vs-p90-on-a-280z-short-block/ Share on other sites More sharing options...
October 31, 200321 yr comment_55433 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. Link to comment https://www.classiczcars.com/forums/topic/8661-e31-vs-p90-on-a-280z-short-block/#findComment-55433 Share on other sites More sharing options...
November 2, 200321 yr comment_55539 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 Link to comment https://www.classiczcars.com/forums/topic/8661-e31-vs-p90-on-a-280z-short-block/#findComment-55539 Share on other sites More sharing options...
November 2, 200321 yr comment_55548 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. Link to comment https://www.classiczcars.com/forums/topic/8661-e31-vs-p90-on-a-280z-short-block/#findComment-55548 Share on other sites More sharing options...
November 3, 200321 yr Author comment_55758 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 Link to comment https://www.classiczcars.com/forums/topic/8661-e31-vs-p90-on-a-280z-short-block/#findComment-55758 Share on other sites More sharing options...
November 4, 200321 yr comment_55835 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. Link to comment https://www.classiczcars.com/forums/topic/8661-e31-vs-p90-on-a-280z-short-block/#findComment-55835 Share on other sites More sharing options...
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