Best way to fix this 340 manifold

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bluesuitah

bluesuitah

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Wondering the best way to fix this hole in a 340 manifold?
 

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Is that a through hole? Nickle rod braze it or take it to a wrought iron gate place with a 6 pack of beer. They should be able to weld it with their equipment in about 5 minutes. Then you can grind it back down to stock shape. A youtube guy repaired a crack with stainless wire and a Mig welder. Heat it up so its dark red, zip it with the mig, peen it goodand stick it in a bucket of sand for 3 hours to cool slowly.
 
Just thinking out loud here. How can it leak with the bolt in and a flat washer on it. Seems it would just be dead space.
 
tekslk said:
j b weld
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Too hot, it'll fail quickly.you need some metal filler in there. How about a paste of POR-20 and iron filings baked in oven for a few hours to set it? Supposed to be good to 1500, just dont turbocharge it or run it lean or retarded. I think 1500 is way over what a tuned car runs at.
 
daredevil said:
Just thinking out loud here. How can it leak with the bolt in and a flat washer on it. Seems it would just be dead space.
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That's true. I've seen that before. It's really not an issue. If you fill it, I doubt if the bolt will still fit through.
 
daredevil said:
Just thinking out loud here. How can it leak with the bolt in and a flat washer on it. Seems it would just be dead space.
Click to expand...

Porous casting or impurity in the metal used to cast with, over time the engine heat and exhaust gas eroded it away.
Kind of like a sand blaster hitting a rust hole in a fender.
 
I think the best way to make the manifold functional is to get a machine shop to ream the hole and press a sleeve into the hole. You could even cover the sleeve with high heat silicone before installing. This method would seal the hole going into the exhaust chamber and give you a good solid hole for the bolt. Of course you could also install the bolt after filling the hole with silicone but some of the silicone might ooze into the exhaust flow space. You could also get a thin piece of metal (roof flashing) and using silicone bond it to the inside of the hole (hole in the exhaust flow chamber), bond it to the inside of the bolt hole. The small metal piece would temporarily cover the hole so you could pump silicone into the bolt hole without it leaking into the flow space. Then pump silicone into the hole before you install the manifold bolt plugging the exhaust leak.
But the sleeve would be the best method. You could probably do it yourself if you drilled the hole out just enough to get a sleeve (metal tube made of copper or steel). If you find a metal tube the correct size before you drill it out you can better pick the drill size. If you can get a good fit (slip fit) you could probably silicone the sleeve in place and permanently plug the hole.
GOOD LUCK>>>>>
treblig
 
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