That makes no sense at all J. Sound like one of those old wife’s tails like hot water freezes faster than cold. I think if I were you I would smile and give a hardy handshake and say thank you but no thank you and go lookin' for another mechanic.
The torque spec takes the bolt to the proper tension I can't imagine why you would loosen it up then retighten it not using the spec. At the proper torque value the bolt is actually stretched just below the yield point of the material. If you’ve ever taken a piece of metal and flexed it a little, just enough for it to return without distorting it’s original shape then that is what you're doing when you torque a bolt. If you bend that piece of metal a little further and it stays bent then you have gone beyond the materials yield point.
Many manuals will tell you not to reuse head bolts, that you should replace them when you do any cylinder head work. The basis for this is that taking the bolt to the maximum torque can in some cases cause the bolt to stretch beyond the yield point, once you have done that it no longer has the same tensile strength of the original material and will keep loosing strength till it fails. I personally have always reused head bolts and have never had a problem. It would be a different story if I were working on something such as a Winston Cup car where you could not afford to have a failure. Chances are that if you had a bolt fail on your Stovebolt the worst case would probably be a water leak and you would have to replace the gasket.
Denny Graham
Sandwich, IL
