Can a simple re-torque of the head bolts as part of a schedule help keep the heads healthy?
We torque the heads on the race car after every race to keep the gasket seated. Third year on same gaskets and heads and we run a LOT more heat and pressure than a road car. We have a Steel block and alloy heads.
Just a question.

 

the problem being what would you re-torque them too.
According to the rave is 15 lbs then a 1/4 turn and another 1/4 turn.
Would you go another 90 degrees or do you have a pound per square foot number in mind?

 

I bought a torque wrench that does deg so if a quarter is 90 deg then half is 180 deg after your 15 lbs then I would BACK OFF in sequence one turn (360 deg) then to 15 lbs then the 1/4 plus 1/4. That is how I do the heads on the racecars. Engine MUST be cold.
Review BACK OFF one turn on all in sequence THEN torque back in sequence.
DO NOT REMOVE BOLS OR BACK OFF MUCH MORE THAN 1 1/2 turns all you are doing is to restretch the bolts that can slack after heat cycle.
If I am 100% wrong then please tell me since I just did this on the 2001 P38 and will do the 2000 D2 that now has 245,000 on the clock.

 

The bolts are torque to yield (TTY) bolts. When the bolts are first installed, they yield (permanently stretch). I would not reuse them.

Every fastener has an elastic limit, (yield point or "the threshold of yield"). Up to this point, if the load on a fastener is released, the fastener will spring back to its original length. When a fastener is stretched into the yield zone, some of the elasticity is permanently lost, and the fastener will remain somewhat elongated when the load is removed. The further the bolt is stretched into the yield zone, the more elongation it gets.

 

This guy knows what he is talking about.

 

yes that is the problem if you use bolts, they they are a one time deal. if you used ARP head studs it a possibility.
once again what would you aim for? a believe ARP say some where around 80 lbs, would you re-torque to 80 lbs or go above that (which is scary)

 

I think you meant 80 ft.-lbs. If you have ARP studs you could just see if they are still at 80 ft.-lbs. but I would doubt you would see them getting loose.

 

You are correct lbs not psi.

 

drowssap wrote: "yes that is the problem if you use bolts, they they are a one time deal. if you used ARP head studs it a possibility. once again what would you aim for? a believe ARP say some where around 80 (ft.)lbs, would you re-torque to 80 (ft.)lbs or go above that (which is scary)"
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Yes. However, Beware that when re-torquing head bolts on this engine, an all aluminum block with all aluminum heads, that potentially there is risk of stressing the thin aluminum wall (too thin, actually) of the block, which is between the outside perimeter of cylinder liners and interior wall of water jacket, which, under borderline excess heat, is prone to cracking. That is where, in the block, some of these head bolt threaded holes are, exactly where 99% of the block cracking takes place on these engines, often leading to loose, dropped, liners and other problems. That is precisely why ARP studs/nuts are much more suitable, rather than stretch head bolts. The ARP studs/nuts create a more uniform, even, force overall, with less stress on any given single bolt hole in the block, where such cracking takes place.

 

OK so new head bolts and torque them to specs. Thanks.