Check out this video of the first 90* tightening. I used a 1/2" telescoping ratchet from Harbor Freight (THIS ONE). I checked with my manual beam torque wrench and the torque was 35-37 ft-lbs after the first 90* turn.


I also used the same ratchet for the 2nd 90* tightening. I didn't check what the final torque was on the final 90* turn. I could have definitely tightened them past the last 90* turn without having the threads go. They were very tough to remove (had to buy a 1/2" 25" breaker bar to get them off) and tough to install with the engine stand moving on me.

 

It's been a while since I have been on here but I did get the disco back together. I did not check the torque this time, but I cleaned all of the oil/coolant out of the head bolt holes this time and it seemed to torque down a lot smoother. When it was all finished it even started up and ran great on the first try. Now just I just need to get a few smaller things done before its 100% road worthy.

 

OK, don't shoot met yet.
Can someone explain how is the bolt stretching mechanism is working ?
I was under the impression that heat was responsible for the tension relief in those bolts. But if the stretching occurs in their cold situation, overtorquing is destroying them.

 

They are designed to distort (stretch) at a proper torque. Then in a very basic view, they act like a spring keeping pressure on. Just use them once. Some can measure them and compare specs and perhaps re-use. I just ordered another bag of bolts.