Thread Sealant

John Vardanian · Post by **John Vardanian** » Tue Apr 10, 2007 2:16 pm

Oil is seeping passed the threads of the exhaust manifold studs. Any idea as to the best thread sealant for this application?

Thank you.

john

Jimmyr · Post by **Jimmyr** » Tue Apr 10, 2007 10:10 pm

John, looks like ime for valve guide seals! Anyway new exhaust gaskets would be the best bet as they do the sealing not the threads. Jim

John Vardanian · Post by **John Vardanian** » Wed Apr 11, 2007 1:01 am

[quote="Jimmyr"]John, looks like ime for valve guide seals! Anyway new exhaust gaskets would be the best bet as they do the sealing not the threads. Jim[/quote]

Actually, it is the studs leaking and not the valves. The ports are quite dry.

The stud bores are heli-coiled and I suppose the drilling may have gone too far on some. The pourocity of the early heads is such that it is denser closer to surface and not so dense in the heart (I am told).

This is probably why oil and water tend to mix in cylinder heads that are converted from hairpin valve springs to coil.

john

airsanford · Post by **airsanford** » Wed Apr 11, 2007 9:02 am

Pull the studs, re-install with Permatex #2 on the threads.

Lee, GTE 2811

John Vardanian · Post by **John Vardanian** » Thu Apr 12, 2007 12:07 am

Done that with Loctite 567, hi-temp thread sealant. It lasted about 500 miles before the leaks started again.

john

airsanford · Post by **airsanford** » Sun Apr 15, 2007 12:11 am

With all due respect, thats why I suggested Permatex #2.

Lee, GTE 2811

John Vardanian · Post by **John Vardanian** » Sun Apr 15, 2007 12:26 am

Hi Lee,

I tried to look up that #2 stuff on Permatex website, but I don't think it is listed under that name. What is that exactly?

Thanks.

john

airsanford · Post by **airsanford** » Mon Apr 16, 2007 10:34 am

go to www.permatex.com

there is a search box. put in "2B" and it will take you to the product.

It is old fashioned stuff- shellac base- doesn't set up hard. It is widely available at auto parts stores. I worked for a BMW dealer in a past life, we used it for the express purpose of sealing studs for oil leakage.

Lee, GTE 2811

John Vardanian · Post by **John Vardanian** » Mon Apr 16, 2007 12:09 pm

Thanks Lee.

john