On the piston engines, (Fiat) we retorqued after each heat cycle. I have the record for reusing the same head gasket on the dyno engine, after changing cams or a port shape, I got to 13 before it let go.

 

The procedure is to back off the bolt a turn, and run back up to the torque, without stopping the wrench. Checking a torqued bolt once it stops turning, tells you nothing. It can be under torqued, and still click the wrench set at a higher number than that bolt was torqued too.

 

So you get into the habit of the wrench moving right through the click. 

 

The torque was supposed to be 55 pounds dry, but we used 50 pounds with hypoid on the threads and anti-seize under the heads and both sides of the washer. We were really leaning on that (stock) gasket with 245 pounds of cranking compression.  We did loose many bolts. Some while torqueing up, and some after one heat cycle, because we were in the upper end of their working range at 50 pounds. So a heat cycle would really load them up, when the aluminum head got a bit taller. I used only bolts from the dyno engine, (used bolts) as so many stock bolts were faulty right out of the box.  

 

 

Even if the two bolts were left loose, the whole sequence needs to be run. If there is no oil in the water, or oil leaks between the irons and the rotor housings, or water in the oil, I would retorque the whole mess and forget it.

 

Never heard of a Fiat race car? We had a qualifying lap record, and won the race one year, at Elkhart Lake's Road America.

 

Lynn E. Hanover