Re-Torque 81SC

[SC-Alfa]

I know this topic has been beat to death in this forum and elsewhere. But here it is again.

Just had a top end rebuild done and Racewear head studs installed. I have searched this site and the advice seems to be all over the place on re-torquing these studs. Back off and torque, just check the existing torque without backing off first...

So, in an attempt to clear things up, I called Racewear today and was told that (unlike water cooled engines) because air cooled 3L 911 engines like my 81SC use metallic gaskets the engine assembly is essentially "metal to metal". Because of this I was told re-torquing was not necessary.

I told the Racewear guy that I intended to take the valve covers off anyway to reset the valves, "so why not re-torque while its apart?" He said that was fine if I wanted to do it, but recommended that I back off the nuts one at a time and re-torque to 24ft/lbs.

One important thing I noted was that he said his re-torquing procedure only applied to Racewear studs. He said factory studs use "break-away torque" and the procedure for them is different.

Thoughts?

[JJ 911SC]

To re-torque you have to back off first and then torque to the proper value.

[SC-Alfa]

To re-torque you have to back off first and then torque to the proper value.

Although your opinion is in line with the Raceware reps, I have seen others on this forum and elsewhere state just as emphatically that you only need to verify the existing torque.

Any other opinions out there?

[Flat6pac]

If youre going to back off the torque you really need to relube the threads because a dry torque is a false torque.
Bruce

[Eagledriver]

Generally the idea is to check that none of the nuts has become loose. I don't even use a torque wrench sometimes. If they are loose it will be very apparent when you start to tighten them.

-Andy

[Ronnie's.930]

Originally Posted by Flat6pac

If youre going to back off the torque you really need to relube the threads because a dry torque is a false torque.
Bruce

I am in complete agreement with Bruce, and the Racewear "tech's" advice seems silly to me. I too have Racewear studs, though in a turbo engine, and I simply set my digital torque wrench to what I want and then turn until I hear the "beep". The last time I did this, I think about three of the nuts tightened slightly (though was hard to tell) . . .

[SC-Alfa]

Quote de Flat6pac

If youre going to back off the torque you really need to relube the threads because a dry torque is a false torque.

Bruce

I am in complete agreement with Bruce, and the Racewear "tech's" advice seems silly to me. I too have Racewear studs, though in a turbo engine, and I simply set my digital torque wrench to what I want and then turn until I hear the "beep". The last time I did this, I think about three of the nuts tightened slightly (though was hard to tell) . . .

But this method only results in a measurement of breakaway torque. But I guess, since this is a higher torque value, we would know that we have at least met the engineered torque value. However we don't know if we've exceeded it.

Given the Racewear guy didn't even think the torque needed to be checked, I think I will decide to Flat6's method.

I don't, in general, think its wise to dismiss the advice of the manufacturer.