Head bolt sealer?
 

I am rebuilding my SBC and noticed sealer on some of the head bolts when I removed them. Does there need to be a sealer applied when reassembling and if so what should I used. The motor will be stock.

A good quality pipe dope always worked for me.

ARP sells sealer under their name. However it is really Locktite PST. Don't scrimp on this seemingly minor item. Use good stuff.

I've been using #2 permatex for years. If you use it ( or anything) on one bolt, use it on all of them equally.

BT :cool:

I've been using Chem-Tec red high temp RTV after having leakage around the head studs on one of Dyno's engines. Used Permatex the first time around.

Crazyhorse... are you saying the #2 permatex failed to seal the threads and the only change you made was to RTV then all was well? How long did the permatex take to start leaking? This is not good new too me, so some substantiating detail would be appreciated.

BT :cool:

The last time I did mine I tried permatex hylomar. I don't know how this will work out. Hylomar (I think that is how it is spelled) was made by rolls royce to seal their jet motors. It is a non hardening sealer.

Has any one else tried this stuff???

Ihave always used Permatex #2 and never had a problem.

Dyno had a cylinder head stud kit that he wanted to use on one of his engines and after using Permatex on the studs the water seeped out of the fine threads above the nuts and washers. I will say this- I've never had any kind of leakage issue with stock or aftermarket cylinder head bolts, and up until recently, I never used any sealer on the threads. I lubricated the threads and torqued the head bolts.

Use a small amount of teflon thread sealer on all the bolts or studs and you will be fine.

GM HAS A LIQUID TEFLON SEALANT FOR HEAD BOLTS.IVE USED IT ON BIG BLOCK 454'S WHERE THE HEAD BOLT HOLES GO INTO THE COOLANT PASSAGES WITH NO PROBLEMS.I THINK ANY OF THE SUGGESTED SEALANTS WILL WORK.I HAVE LEANED TOWARDS THE TEFLON BECAUSE I FIGURED IT WOULD GIVE A MORE EVEN TORQUE DUE TO THE FRICTION QUALITYS

Tried the teflon stuff Loctite s, ARP s and got nothing but leakage looked like the threads were to tight to let it in between. Ended up using Locktite 262 I believe at the time didnt have much choice but hasnt leaked since.

dave, some of the bolts go directly into the water jackets that cool the cylinders. they need sealant or water can leak pat the bolts and get in your oil. it is a good idea to use it on all the bolts for even torque readings. be sure to run a tap through all the holes first to clean out any sealant left in the block.
this is my preferance, bolts are fine but i like studs better with permatex liquid teflon thread sealer. if you ever retorque the heads, you won't disturb the sealant using studs. it is overkill but also cheap insurance to me.

Thanks for all the replies. I think I'll just use the permatex. I am an engineer and can tell you guys from past torque testing exp. that the teflon sealers will increase the the preload (strech) on the bolt at the same torque, possibly to the point where the bolt could fail.

That what I was thinking Dave. This is why suggested torque values are changed for different thread materials. Teflon has a very low coefficient of friction and will give a higher effective clamping force. If the yield strength of the bolt is exceeded trouble will be close behind.

BT :cool:

that is too much tecnical mumbo jumbo for me, but if you use teflon to seal studs, the clamping force won't change because you use oil on the threads by the valve springs. the threads coated with teflon in the block don't turn while torquing. ;)

Most of the engine builders i know use
Indian Head sealer, it has been around
about 40 yrs. It can be bought at Auto Zone
Loy