naviathan Posted May 29, 2008 Share Posted May 29, 2008 Yep, it's about time, but I did it. I finally got around to pulling the head off the 81 again. Judging by the white crust in the exhaust ports of cylinders 3,4,5 and 6 I really did a number on this one. All part of the learning curve I guess. N42 head + F54 Flat Top = 10:1 Compression and on 87 octane it makes bad things happen. Fortunately it looks like the head gasket was the only failure. Number 6 blew on the head side of a blocked water jacket; why is this water jacket blocked? Pics: Gasket blown on head side... Block water jacket at the blown spot... Head water jacket at the blown spot... Why block a water jacket in the rear of the engine where we have the worst problems with hot spots? Anyhow, working on ARP head studs, 2mm MLS head gasket, 34# injectors, 14mm o-ring fuel rail end maybe a mild port job while the head is off. Quote Link to comment Share on other sites More sharing options...
X64v Posted May 30, 2008 Share Posted May 30, 2008 I came across this problem on my engine, an F54 bottom end with an E88 head. Turns out, the P-79 and P-90 heads use different holes for getting water to the head than the earlier heads, so the gasket blocks off some. Go look at post #121 in the thread 'Head cooling on cylinder #5' in this sub-forum, it explains the changes well. Quote Link to comment Share on other sites More sharing options...
naviathan Posted May 30, 2008 Author Share Posted May 30, 2008 Thanks for the heads up on the thread. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.