s14280zx Posted February 22, 2008 Share Posted February 22, 2008 I'm planning on building an engine for both of my cars, a 1979 280zx, and a 1978 280z 2+2. I will have a triple weber 40mm setup on the '79, and I was trying to keep the '78 stock looking with fuel injection. I have two F-54/ P-79 engines with under 90,000 miles on them. Would I be better off changing to the N-47 heads raising the compression, or should I keep the P-79 heads on and use them. Would it make a noticable difference between the two compression ratios with fuel injection? Thanks For The Info. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted February 23, 2008 Administrators Share Posted February 23, 2008 I'm planning on building an engine for both of my cars, a 1979 280zx, and a 1978 280z 2+2. I will have a triple weber 40mm setup on the '79, and I was trying to keep the '78 stock looking with fuel injection. I have two F-54/ P-79 engines with under 90,000 miles on them. Would I be better off changing to the N-47 heads raising the compression, or should I keep the P-79 heads on and use them. Would it make a noticable difference between the two compression ratios with fuel injection? Thanks For The Info. This exact topic has been covered and recovered around here. Use the search function and search for “L-28 detonation”, etc. In sort, do NOT put the N-47 head on an L-28 with Flat-top pistons. You can only increase the compression ratio so far on the L-28 with open chamber heads before detonation sets in, and at that, is VERY expensive as it will cost you a custom set of pistons. At least $600-$800 for pistons not including the rest of the rebuild parts and machine work, all for a mild bump in compression ratio that might net you 5-8 HP? Not worth it my opinion. Better places to put that sort of money for more return in power. Stock flat tops with the Z car N-47 is too much compression for premium pump gas! Again it is has been covered… Good luck, Paul Ruschman HybridZ staff Quote Link to comment Share on other sites More sharing options...
s14280zx Posted February 23, 2008 Author Share Posted February 23, 2008 I appreciate all the great advice you've been giving me. I have bad luck searching most of the time, and I like to ask questions that are specifically for my application, rather than searching for, and reading numerous threads that may or may not have the info I need. This way saves me alot of time that I can use working on my cars. Thanks for the help. Quote Link to comment Share on other sites More sharing options...
strangethursday Posted February 25, 2008 Share Posted February 25, 2008 This exact topic has been covered and recovered around here. Use the search function and search for Quote Link to comment Share on other sites More sharing options...
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