Re-Sealing End Header Bolt 440 Iron Heads - Any Tricks?

[Photon440]

If you insert a stud and it still leaks, well...
This stuff plugged up a leaky head gasket on a neon I once drove. Saved me a lot of work.

 

[miller]

For what it's worth...

On my current pair of 906s, also on all others I've done, always used Indianhead Shellac sealer. Studs, or bolts, though all mine are studs. My current heads, also needed help on the stud holes, everyone of them took a helicoil. Yes, they all sealed great. Depends on how it's done. Sealer went on outer threads of the helicoils, let cure.
If you have some kind of thread insert in the head, need to make sure the leak isn't between it, and the head's threads, first!

 

[PurpleBeeper]

For what it's worth...

On my current pair of 906s, also on all others I've done, always used Indianhead Shellac sealer. Studs, or bolts, though all mine are studs. My current heads, also needed help on the stud holes, everyone of them took a helicoil. Yes, they all sealed great. Depends on how it's done. Sealer went on outer threads of the helicoils, let cure.
If you have some kind of thread insert in the head, need to make sure the leak isn't between it, and the head's threads, first!

Hey Miller, I've been thinking about if I have an insert leak (instead of a header bolt/stud leak). How could I tell if it was the insert-to-head that is leaking?

I mean, it "might" be obvious, but I like to be prepared before I pull an engine apart. I can't really pressure test it without a header on that side. For what it's worth, it does not leak until the engine heats up...then drip, drip, drip right onto the header.

 

[miller]

How could I tell if it was the insert-to-head that is leaking?

Are the inner threads at the insert blind, or go through? Best way to test it, would be a cooling system pressure test. Cork up the bolt/stud hole, and watch what it does.

If it is leaking, probably have to redo it, with some good seal.

 

[PurpleBeeper]

Are the inner threads at the insert blind, or go through? Best way to test it, would be a cooling system pressure test. Cork up the bolt/stud hole, and watch what it does.

If it is leaking, probably have to redo it, with some good seal.

Gotcha. The insert's inner threads go all the way through. That's why I'm not 100% sure if it's the inner or outer threads that are leaking and I want to be prepared before I pull off the header. Your idea about a pressure test of the cooling system makes a TON of sense, especially if I end up putting a stud back in that hole. THANKS!