Sealing head bolts into water jacket on a SBC

[tvrolet]

Well, at long last I cracked the overheating problems on the tvrolet (small block chevy). Slight leak in the head gasket; it would tick over forever without overcoming the seal, but under hard running/pressure there was enough gas getting into the cooling system which would collect in the 'high points' that it would start to cause the water to get expelled from the system, and lead to overheating. No signs of oil in water or water in oil, but final proof was I could pressurise the cooling system and after a while I'd get water collecting in #1 bore.

OK, so having stripped it all down I put it back together and sealed the bolts with Loctite 572. Pressurised the cooling system before running, and had a leak off #7! Stripped it down again and I'm sure I've got a warped cylinder head. So, I'll get that skimmed off and try again.

But, I'd have expected the loctite to have hardened. Although maybe it did on parts of the threads, but there was plenty of un-hardened stuff on the tear-down. I've heard some folks using silicone sealer, but I'd have thought it would have started to cure well before you could get all the bolts properly torqued down. Also heard some folks using teflon plumbers paste (never seen the stuff, but I gather you get it from plummers merchants).

So, what's the views of sealing the bolts into the water jacket? Loctite 572 (the white stuff), RTV sealer, teflon paste, anything else?

[eliot]

I think i used silicone on mine.

[350Matt]

Bit of threadlock / sealer and a dowty washer under the head

Matt

[That Daddy]

Wellseal or silicone/RTV is all you need to seal the studs,make sure you use something i have witnessed what happens if you dont on the SBC make sure the studs & threads are oil/grease free when you apply your sealer

[Steve_D]

The oil remaining on the bolts or in the thread are your main issue as it is difficult to clean the thread in the block.
Silicon is not your best bet.
You need an oil tolerant product such as Loctite 572. Apply it to the threads and around the bolt head and washer.

Steve

[That Daddy]

Threads in the block cleaning/degreasing no problem,brakecleaner/carbcleaner or acetone with an airline to blow the threads out afterwardsthen chosen sealer

Edited by That Daddy on Monday 10th March 18:22