On my 392 I've noticed some water running down the right hand exhaust manifold whilst the engine sits. It's coming from a manifold mounting stud where it enters the head. If so what's the best sealer to use considering the heat in that area. I'm thinking a high temp silicone maybe or should I use a ptfe tape on the threads. Thank you....
Red high temperature RTV would probably do it. No problems with removing when you have to. The small town Central California speed shop I used to frequent recommended red RTV as a bolt locking compound on header bolts. Worked great, the bolts didn't back out on their own and were easy to remove when required.
Same goes for the valve cover bolts... they are also tapped into the water jackets. Be sure the leak isn't from the rear cover bolts or studs and just dripping on the exhaust manifold...
Thanks for the guidance and the info on the valve cover bolts. We've just traced it to the rear lower exhaust bolt which practically fell out but will check everything else. It's below zero out there today so the fingers are not as active as they should be!
Several vendors supply Teflon paste sealer made especially for bolts/studs. FelPro, ARP, Lock***e..... lots of brands. These days everyone should have some in their toolbox.
Guessing mine would have been fitted with studs originally but they would make manifold removal impossible in this body so bolts it is.
98% of the bolts go into water on a 392. You have to clean, dry & seal every one with teflon thread sealer. The rearmost header bolts go into oil, the rest into water.
Bars Leaks Radiator sealer. It's not the old mol***es type sealer anymore. It's the ground walnut shells that GM requires be installed whenever the cooling system is compromised. i.e. cylinder head removal, intake manifold removal, etc. It'll instantly seal the area around those threads as that's what is was made to do. I've been using the GM pellets for years and only recently discovered that the current Bars Leaks is the same stuff already in solution so you don't have to break up the pellets and mix them in water before adding them to the system.
No tape. You have to use the teflon paste type thread sealant. Something like the Permatex High Temp. Thread Sealant 59235. It comes in a tube. You can't ***emble a hemi and put Bars leak in it and think that'll do it. Ask Bob Walker at Hot Heads what'll happen if you don't seal them all. The valve cover bolts, timing cover, water pump, intake bolts, header bolts, everything except the ones you'd think go into water, the head studs/bolts. Also never use the old style drive in freeze plugs. Spend the money on the stainless ones that tighten in with allen bolts. The stock ones will blow out most of the time.
Good kitty juice when it's hot and running. Apply it when it's cold and clammy. It never works for me. Maybe your luck will be different??????
No sence in even fighting it, just give me the hemi and I will put a few years on the motor and find all the leaks for you, for free.
Oh REALLY! I Must be doing something wrong, then because I've NEVER coated the threads in my hemi for 44 years and I've NEVER had coolant seeping past the threads. I used to use pepper but, when GM came out withe the ground walnut shells, I switched. Now I use the pre-mixed Bars-Leaks stuff. I asked Bob Walker if his valve stem tips were hardened or not. He diddn't have a clue what I was talking about. He's a parts pusher, nothing more. He's, by no means, an expert in anything but selling parts. He's cornered the market on reproduction hemi parts so that makes him an expert, I don't buy that.
Oh, yea, never lost a core plug, either. Like I said, he's just trying to sell you his stock. The original style core plugs work just fine. I've built quite a few engines, hemis, wedges, polys and even Chevys and I've NEVER had a stock type core plug come out in over 40 years.
The factory must have used some type of sealer on their studs to prevent leaks. I use the copper high temp permatex and it works well. But Desoto has me wondering about the bars leak as a way to make sure they won't leak. It is a pain in the *** to get to the exhaust bolts when you have headers and the engine is in the car.
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