Headbolt Actual Torque?

[19963.4lsr5]

Does anyone know what the torque on the head bolts becomes after the 2nd 90 degree rotation?

I do not like how some of the bolts felt doing the last rotation. I oiled the threads and head of the bolts. Some just felt tighter than others and two or three of them seemed to be stretching during the last 45 degrees of the rotation.


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[Joelzy]

no idea on actual spec but some of mine made the last turn a little easier than others. They are after all stretch bolts so i wouldnt be too surprised if you could feel that.

we are talking about a new set correct?

 

[WWRD99]

I never actually tried to measure what the head bolt torque was on these, I can feel them stretch on first and second 90 turn...biggest thing that I do is check set torque several times to make sure the start torque is the same in all of them...I have the torque wrench that does degrees built in so I know that part is spot on too...new bolts I assume too.

 

[gamefreakgc]

I never actually tried to measure what the head bolt torque was on these, I can feel them stretch on first and second 90 turn...biggest thing that I do is check set torque several times to make sure the start torque is the same in all of them...I have the torque wrench that does degrees built in so I know that part is spot on too...new bolts I assume too.

Yeah it's the start torque that matters most. It's not a deal breaker if one thread feels a tiny bit looser than another.

 

[19963.4lsr5]

They are new head bolts. I feel better some of you felt what I did.

I did the initial torque setting in 2 steps. 15 and then 25ftlbs.


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[WWRD99]

They are new head bolts. I feel better some of you felt what I did.

I did the initial torque setting in 2 steps. 15 and then 25ftlbs.


I don't think I've ever done a torque to yield bolt that I didn't feel stretch some so yes that is very normal...the key is going back on the 25 lb set torque on each bolt several times...if I have time I let the engine sit for about an hour after I set the initial torque and check it again before I turn them twice...just to make sure the head gasket didn't settle any...temperature of the head and block need to be the same...like if I just get the head back from the shop I'll let them sit for a couple hours before I do anything...I really don't like problems with something as simple as head bolts not being right!!!

 

[19963.4lsr5]

So, like my 97 thread says I installed the heads again and did much more prep work this time.

Ensuring the head bolts bottom out with my fingers. Ensuring the alignment dowel holes in the head are clean and burr free.

I always wipe all gasket surfaces with acetone.

Torquing the head bolts this time had me working hard for every bolt. None started to stretch on the final 90 degree torque sequence. I busted ass on all 16 bolts. It’s not fun doing this on an engine stand that wants to turn with the torque wrench.

It’s done and I am confident it’s all good this time. Much more confidant than last time.

Gene


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