Thread: Question about TQ specs on head bolts....

I found this is the FSM but I don't understand the reasoning behind the 3rd step...

" Loosen all bolts completely. "

Why is that, and is this what I should really follow?

Now correct me if I am wrong, but the reason I believe they tell you to do this is because as you torque the head bolts down they stretch (slightly) so the reason for doing this is sort of a way to (pre stretch) them this is why the third step the torque is not higher than step 2. Stops the head from separating from the block. It may also help to seat the head gasket correctly as well.

Strain hardening the bolt so that it doesn't stretch in the future, maybe?

Edit, too slow!

yeah wayne, follow the instructions on the FSM and you should be golden. I have installed brand new torque-to-yield head bolts on a Suzuki before w/o any problems.
But i may be wrong but aren't you supposed to do 90 degree pulls on the bolts also?



edit: just checked the FSM and yes after torquing the head bolts down you have to go back and do your 90 degree pull sequence...

tightening torque as per FSM;

A) 29 ft-lbs
B) 58 ft-lbs
C) 0 ( loosen bolts )
D) 27 ft-lbs
E) 90 degree pulls on all bolts in the same pattern as before
F) another 90 degree pull sequence same pattern as A-E...

I have accomplished doing 90 degree pulls on other head bolts w/o an angle wrench just by marking all the head bolts with white touch up paint at the 12 o'clock position , then after your 90 degree pulls the white mark should end up at the 6 o'clock position when finished ...

Really interesting as to how when you retorque the head bolts, you only torque them to 27ftlbs.

The good thing is that they tell you to stretch the bolts and then loosen everything and retorque them. It's a lot easier that way than torquing the headbolts, driving the car thru a few heating cycles, then removing everything to retorque the headbolts (like with ARP's).

Is this the same process for used (or the same set of) head studs going back in???????????????????????????????????

Good question.... What about new bolts?

yeah same as used bolts as long as the threads aren't " necked down
" or stretched, altho a job like that i would always use new bolts

So no matter what new or used... follow the FSM?