I did a search and wasn't able to find an answer to my question. I am rebuilding a LT4 and read that the proper way to torque the head bolts was: #1 run all of the bolts down until they touch. #2 torque all of the bolts (in the prescribed order) to 22 ft. lbs. #3 turn the long and medium bolts and additional 80 degrees and turn all of the short bolts an additional 67 degrees. Are they kidding? How can I accurately turn a head bolt exactly an additional 67 degrees? Is there some special tool out there that is that accurate? Or does everyone just go to some ft. lbs. of torque amount?

Thanks.

 

After you torque to ft pounds, mark the bolt so you can tell how far you turn. Some use a single dot, I like to make a straight line across the bolt horizontially or vertical. Which ever way you do it make sure you mark the bolt in the same place on each bolt incase you get side tracked you can look and tell which ones you have tightened. Don't guess, you might regret it. Not sure on the degress but I believe it depends on what kind of bolts you are using. I believe Shoe boxes web site explains each kind of bolt. Good luck.

 

Just torque them all at 70lbs...new bolts?

Do you know if they're TTY or not?

 

Yes, MachinestOne, they are new Fel-Pro bolts. I claim ignorance. What is TTY?

Ryan, the idea of marking the heads of the bolts is much better than anything I have thought of. But it still seems like you could easily be 5+ degrees off. When they ask for a number that is so precise as 67 degrees, it certainly got my attention.

 

You use a torque/angle meter.

 

Cool. So where do you get one of those? Are Lisle tools usually available at auto parts stores or???

 

Lisle tools are available at most larger auto parts places.

 

I do believe on the earlier LT1's they listed a torque figure in the service manual right at about 65 ft lbs, same as every gen 1 sbc whether it was iron or aluminum heads.

then they changed things up on the later ones to the tightening an addition 80 degrees and so on

both techniques are just trying to achieve the same amount of bolt stretch, in my eyes as long as the threads are clean and thread smoothly you cant go wrong with using either procedure. tightening the additional # of degrees is supposed to be more consistent, but you still have to start out at a certain torque level, in this case 22 ft/lbs, if the threads suck you wont have an accurate starting point anyway.

I would just use the tried and true 65-70 fts lbs going up in three steps as your method, especially if you already have an accurate torque wrench.

How many sbc's ya suppose are on the road that have used this method? As long as your not trying to build an all out race engine i would say go for it

 

If he is using TTY bolts, he needs to use the torque/angle method. If not, it does not matter.

 

Yep.

And if they're not the TTY bolts he needs to make sure he was sold the head bolts with washers for the aluminum heads.