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How to fix a crack in cast alu intake?

General engine tech -- Drag Racing to Circle Track

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Nut124
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How to fix a crack in cast alu intake?

Post by Nut124 »

So, I managed to port an alu intake to the point where I see a tiny crack and some daylight.

This was a thin spot, casting defect, that I did not pay attention to.

How to repair? Weld? Epoxy? The hole is not a structural concern. Just cannot have a leak there.

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ProPower engines
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Re: How to fix a crack in cast alu intake?

Post by ProPower engines »

The best way is to weld it!
Epoxy will do the job but not forever. It is easier and faster if its on the engine already but if not weld it =D>
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jeff swisher
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Re: How to fix a crack in cast alu intake?

Post by jeff swisher »

I have used JB weld inside of carburetors and on outside of aluminum carburetors to fasten on a fuel inlet.
I have never had the Old recipe JB weld come off.
I do not sand it though.
I form it after it begins to set up and leave that slick sealed outer sheen or coating it develops.
Do not use JB Quick.

I have also used JB Weld where the pipe threaded coolant fitting goes in.
I have had friends tighten their fitting too much and crack the casting in that area.
I clean and swab the area and apply JB Weld into the threads and then onto the threads of the fitting and screw them together.
Let set up at least 24 hours before putting into service.

But like was stated if you can weld the area that of course would be best.
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Baprace
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Re: How to fix a crack in cast alu intake?

Post by Baprace »

Nut124 wrote: Wed May 13, 2020 4:47 pm So, I managed to port an alu intake to the point where I see a tiny crack and some daylight.

This was a thin spot, casting defect, that I did not pay attention to.

How to repair? Weld? Epoxy? The hole is not a structural concern. Just cannot have a leak there.

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Nut124 You have an email.
BigBlocksOnTop2
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Re: How to fix a crack in cast alu intake?

Post by BigBlocksOnTop2 »

Not a big deal. Stick your grinder in the hole and go round and round until you have about .100 wall thickness. Cut and form a piece of 1/8'' metal to fill the hole. Have a TIG guy weld it for you and touch up with your grinder. It happens...be glad it's not iron!
Bill Chase
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Re: How to fix a crack in cast alu intake?

Post by Bill Chase »

You could make the hole bigger and mix up some jb weld, while working it make it have some area inside and outside of the port, that would essentially lock the epoxy in place and if it did come loose it wouldn't fly into the head, it would be trapped..

But I agree, this is a 5 minute job for a decent tig welder. Probably minimal cost. And would be the best repair.
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