Welding/modding Cummins exhaust manifolds ???

M

me2

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Has anyone or does anyone know of a way to modify a stock Cummins exhaust manifold ?

Mainly, has anyone cut off a turbo flange on a Cummins manifold and put on a different one, with a different pattern or maybe with a different orientation.

You can't weld cast iron, right ? It will never hold, right ? It will crack and fall off, right ?

Just checking to make sure I am not over looking something.
 
Tig it with a high nickel rod. I'm pretty sure that is how we have successfully welded cast before.

Garrett

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Probably be best to heat it up before you arc weld. It will crystallize and crack. Learned this first hand with repairing big dumb bells.

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Is there a mig wire that will work? Usually only see .030/.35 in shielded/unshielded. Nothing about nickel content.
 
Make sure the weld joint is super clean inside and outside. Pre-heat to sweat the water out, and TIG weld with Inconel 82 wire, 1/16" or 3/32" diameter wire. Try setting the new flange with a 3/32" gap so you can punch thru with the TIG wire for a full penetration weld. Then, if you can, grind the inside down and smooth. Might need a buddy to help with the initial set up of the flange. Just don't shock the piss out of said buddy. Well, unless you want to.
 
Very interesting.

I have a TIG welder. I can TIG weld.

I'd like to cut the turbo flange off a Cummins 6.7 manifold and move it.

Tell me how, please.

Can I make some new sections from mild steel and attach them to the Cummins manifold ? Bolt or weld or ?
 
bulldog77 said:
Probably be best to heat it up before you arc weld. It will crystallize and crack. Learned this first hand with repairing big dumb bells.
Click to expand...
I wouldn't think that dumbbells use high quality iron. I bet the iron in a Cummins manifold is pretty high quality.
 
Id still pre heat as a precaution. And also wrap in a heat blanket or something to let it cool slow. Just my opinion.

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Pre heat then after final welding set in a tub full of sand. It will help the metal cool slower so it doesnt lose as much temper. Or any of its other qualities fwiw


Ryan
 
alot of people tell me in carzy and full of sh!t but in high school i took a kids manifoild cleaned the living sh!t out of it and stuck it in out rod oven to heat it up, welded it up with dual sheild and then put it back in the oven and turned it off so it would cool down slowly with it in there and it help up fine.

might not be the idel way to do it but it was worth the shot and it worked, so take that with a grain of salt as im just saying what I did, and what worked for ME might not work for you
 
My college instructor used to weld cast all the time, with prep and patience it can be done
 
im running my s468 on my cut t3 off and welded t4 on manni for 20k now no issues i cleaned preheated and used regular .045 steel mig , did root and then triple passed it same for wastegate pipe, i do so much welding at work there aint much we havent welded
 
Put it in an oven and bring it up to 400 degrees, the entire manifold. Or torch sink it but make sure the heat is soaked good. Use nickle 99 stick wire.
Take your time when letting it cool. Let the heat drop slowly. The take a ball peen and peen the weld, and peen some more, an a little more. And just for good measure peen it one more time.
Should be all set to go. Cast is tedious and time consuming.
 
07redsled said:
im running my s468 on my cut t3 off and welded t4 on manni for 20k now no issues i cleaned preheated and used regular .045 steel mig , did root and then triple passed it same for wastegate pipe, i do so much welding at work there aint much we havent welded
Click to expand...

Just what I wanted to hear.

Was the T4 flange you welded on made of cast iron or steel ?

Was it a stock Cummins manifold ?

How long and hot were your welds ?

How hot did you preheat it ? How did you preheat it ? Did you keep it hot while welding on it ?

Thanks for the reply.
 
Bury it in sand to slow cool it. You can't cool it slow enough.

Tobin
 
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