Quote:
Originally Posted by Half-Inch Stud
Well, I've NEVER re-torque Head-Bolts on a hot-run engine because I figure the organic gasket material is at it's softest, unfair to re-TQ while HOT. In fact I'd be scared to re-TQ while HOT.
Corollary: Re-torque after a complete cool-down sounds fair game. (if we Monk-like about it, not to cavalier).
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The heck with the organic gasket material... my own organic material is is peril when things are hot.
I havent used header gaskets in 20+ years. (hi temp red only) Used to think it was bolts backing out. Safety wire proved otherwise.(safety wire skill well learned when learning aircraft maintenance) Cured rtv only compresses to a point and I use a pretty thin amount. Only enough to fill voids and have enough stretch for expansion/contraction cycles. So... after figuring out the bolts arent turning and sealer containing seal and not leaking.(Debs street car 8 years as of last month) The bolts are stretching after heat/cool cycles??? Then hit point where they no longer stretch? Or hit point where expansion contraction equalize? Cant be rtv as it would have "glued" like loctite and not allowed much if any movement in first place and once disturbed from "sealed" would stay "loose".
Only talking header bolts or studs here and I've never put a tq wrench on them(ever in my life). Probably will If I ever need to remove them. Hmmm maybe I'll go loosen one later and see what break-away torque is then retighten to same tq. Check tq again Sunday night. Maybe learn nothing or something.
Just have to wonder about thermal cycles on heads/block/gasket/fastener. At what point do gaskets stop crushing? Heads too? What happens to fastener that is constantly heat cycled? Lose temper? I cant see how it could help itself.
Seems good maintenance to check fastener torque though.