headbolt question???????

[55special]

Do you guys put anything on your headbolts before torqueing(sp) them down.
The machine shop i used to frequent just dipped them in oil but i took apart this 400 sb chebby and it had a hardend white sealer on the threads. Just curious, we're putting the heads back on tonight.
thanx
chad

[buick64203]

The white sealer on the Chevy head bolts is because the holes in the block go into the water jackets on those engines. If you didnt, they would leak antifreeze! Basically non hardening pipe sealer. Im pretty sure all the holes on a Buick engine are blind. I would just brush some some light oil on them with an acid brush before torquing them down.

[SS-TRUCK]

Jason you are very correct on the sealer on Chevy head bolts , also the sealer keeps the bolts from corroding in place . I have had to throw many away because of missing metal on the bottom end . On the Buick bolts I would use anti seize as a lube and to keep from seizing in the threads . Just my 2 cents worth .

[telriv]

Chad, there are 3 bolts that go into water on the "NailHead". Those 3 are under the rocker arms & need some type of sealer. The rest are blind holes. Just make absolutely sure you have the correct length bolts in the other 11 spots. If you use a bolt that is too long & try to torque it down without knowing & being forewarned you could actually crack the block.

[chris lee]

i also run a tap through all the head bolt threads with a little brake cleaner
to clean and debur the block threads.:Comp:

[Free Riviera]

I used anti-seize

[Bent6]

Wire wheel the bolt threads and use 30w motor oil on the threads - especially the bottoms of the bolts. Don't forget a little thread sealant or you'll have milk for oil.

[55special]

Thanx for all the great tips. We tapped all the holes and ran a die on all the bolt threads. Then we used loc tite pipe sealant w/teflon. Worked great
thanx again
chad

[bobc455]

One other thing to consider on the subject.

When you tighten headbolts (or bolts in general), it is critical to know whether the given torque values are with lubricant or without.

A bolt is essentially a tension-generating device, to clamp to things together, and a given torque spec will correlate with a given amount of tension. If you put lubricant on a bolt that is not intended to have lubricant, you are generating about 20% more tension when you tighten to a given torque value. (Alternately, you can set your torque wrench about 20% lower when using lubricant on a thread which does not normally have lubricant. A good example of this situation is when you apply never-sieze to wheel studs, you should decrease the setting of your torque wrench by about 20% if you use never-sieze on a wheel stud).

If you lubricate a bolt which is not normally lubricated, it is possible to stretch/yield the bolt, which can make the bolt more prone to breaking (either during torquing or in service).

-Bob C.