lose heads

I have 72 SP which the drivers side head become lose on. It sounded like I had glass packs on the thing. Anyway I had the bottom bolts tighten and for now things are fine. The engine is only 2 to 3 years old. What would cause the heads to become lose? Over heating? I'm sure my problems will return.

Reply to
benntn
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Several things can cause it..but what I have been told is improper torque settings or improper torquing sequence. the head studs also sometimes pull out of the case. My .02 FWIW Jeremie

1972 SB
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Reply to
VdubBeetle1972

Yeah, overheating. Overtorquing will do it

Also, not using a proper pattern when torquing the heads down. Which is what you just did by only dealing with the nuts you could reach without dropping the engine.

Reply to
Max Welton

This all maybe very true but the engine is three years old and I been driving it everyday since. So what would cause it to do it now? I would think that if this was not done in the first place then this would have happen a long time ago. The engine was a crate engine so when it was install the heads were not touched. The manufacture would have done it last. I figured that by just doing the bottom bolts would not do me much good except by me a little more time without having to drop the engine.

Reply to
benntn

The bottom nuts get loose easy because they are constantly soaked with oil. Add to that the thermal expansion and contraction. The top nuts on the other hand are in a dry area, and would therefore be less prone to working themselves loose.

True, you should do all of them, but tightening just the lower ones might save you a cylinderhead or two if you don't have time to drop the engine just yet.

This is a common problem and one thing I do to prevent it is use sealant in the threads when assembling the engine. Not Loctite thread locking glue, but just some soft sealant. Even silicone sealant would work here. It stays soft while you torque the nuts down and dries to sticky rubber like material with time, which will stop the nut from turning freely due to vibration and whatever. I put it under the washers too to prevent oil leaks. Surfaces have to bee free of oil and dry.

Jan

Reply to
Jan Andersson

Was it based on a new case or a used case (engine may be 30 years old in that case!)? Did the new engine have case savers installed in the case halves? If not then the threads may be pulling out of the alloy. Although they sell larger/course threaded replacement bolts they are a temporary fix until the engine can be pulled and threaded inserts installed.

Reply to
Wolfgang

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