The Stovebolt Site Forums The Shop Area Engine Shop head bolt replacement

I heard that I should replace the head bolts whenever removing the head because of elongation. I didn't do that on my 62 235 that I just got done rebuilding. I haven't started it yet. Should I order some new bolts or should I be good?

The original old bolts can be re-used, unless they appear to be damaged or distorted (burrs or nicks) in any way. The threads on the old bolts should not be re-cut with a die. You should be able to easily hand-install the bolts.

I think the more modern Torque-To-Yield (TTY) head bolts are the ones that should not be reused.

thanks for the fast response. The bolts were all clean and solid. Didn't have any problems with them. Just didn't want to have anything go wrong down the road.

To get the best torque values, always lubricate the threads as you reinstall them. DO NOT use an excessive amount of lube, as it can fill the area under a bolt if it's a blind hole, and you'll get a hydraulic lock that simulates the proper torque value. A little motor oil applied with a small brush is plenty of lube, and just a bit of oil under the bolt head is also good. If you use a thread lube like Never-Seez, reduce the torque wrench setting by about 5%.
Jerry

check the threads for necking....thinning in the area of the threads caused by stretching...

I put some thread locker on them. Is that going to simulate an improper torque?

As long as the bolts were tightened before the threadlocker set up, you should be OK. I wouldn't reccomend doing it again, though. A properly-torqued bolt doesn't need any help keeping itself tight.
Jerry

Question: When I installed my head on my 261, all of the bolts except one torqued right to specs. I ran the truck (after the engine rebuild) for a while and then checked the torque. All of the bolts wer still good except one which was asking for a bit more. I gave it a little extra but it gave me the feeling that it might snap off so I quit. I have not experienced any problems with the head, compression is good, etc. Should I leave it as it is?

That bolt is stretching. It would be a good idea to replace it with another one.
Jerry

Thanks Jerry. So, when I replace it, remove the old one, lightly lube the threads of the new one and torque it cold to specs. Then run it until hot and then retorque?

Sounds good to me. It wouldn't hurt to run the rest of the bolts, in sequence, just to be sure none of them have loosened up. Not likely, but especially if you've got to have the valve cover off anyway, it can't hurt to double-check.
Jerry