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I will be installing the new heads probably next weekend and was wondering if I could get the torque specs and patern for FE heads?
I searched and all I found was torque specs for all external items (water pump, cam gear and so on)
Thanks for the help.
Ken
I posted a picture of the torque sequence in my gallery. Here's what Chiltons says on the procedure:
302: tighten all bolts to 50 ft. lbs, then 60, and finally 70 351M, 400: tighten to 70, 80, then 95-105 All V8's except the 302, 351M and 400: 70, 80 and then 90 ft. lbs.
Just a note: these are for stock heads, anything other than that I wouldn't know
I hated to bring this one back from the dead, but does anybody know if those specs refer to the bolts being dry or oiled? It does matter. I just don't know which way to go.
Never dry.
Never.
Please.
You'll just tear the threads in the block up.
On threads that go through to water (some do on some blocks) you use a little teflon paste - not tape.
If you can tear up the threads in the cast block with steel bolt threads, you are doing the impossible. But you are right, they should be lightly oiled. See what happens when you use an old memory instead of looking in the book.
Well, the reason it matters is not because you'll tear up the threads. It has to do with the tension on the bolt. 80% of the torque registered on a torque wrench is from the friction in the threads and from the bolt head on the mating surface with only 20% actually coming from the clamping force or tension on the bolts. Oil the threads, and you reduce your friction and cause your clamping force and tension on the bolts to increase above what you would get when the bolts are dry.
I do a bit of road racing and people call me crazy because I tell them not to oil or use antiseize on their lug nuts. In this case, where you are changing tires often, it isn't needed. I have seen guys never have a problem with lugnuts until they oiled them or put anti-seize on them. After that, they started snapping lugs off all the time. They just thought they needed to put more oil on until I explained to several of them that the oil was causing them to stretch their lugs past the failure point because it was actually like putting a much higher torque on them than needed. Now on fasteners that you don't plan on taking out much...use antiseize or pray to the easy-out gods for help.
I'll just assume that the torque spec was set using oiled bolts then as it sounds like nobody has had a problem doing it this way.
Are 390 head bolts the same as 360 head bolts? I'm having a helluva time finding new head bolts for my 360. For instance, Summit carries head bolts for 390-428 FE but nothing else that is close. Any ideas?
And although you are 100% correct as to torque values - you can tear up threads in cast iron pretty easily. The material is comparatively brittle, and dry binding and releasing will introduce fatigue at the root of the threads - causing individual pieces of the threaded area to pop off. Pretty common to see on frequent change FE fasteners - - like water pumps or thermostats. Shows up on my older blocks from time to time in other locations.