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Help welding a custom manifold.

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Old 07-03-14, 10:01 AM
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Help welding a custom manifold.

I'm thinking of investing in a welder and was wondering what I would need spec wise for welding up an exhaust with the 1/2" flange from RB to the ~1/8" tubing for everything after and up to the turbo flange, however thick it may be.

I know how some basic wire welding with body panels and such, most things being of equal size, just don't think 1/8" settings would penetrate the 1/2" flange.

How does Turblown, Neukin, and others do it?

I'm mainly wanting to weld up something to clear my 6-ports, as I'm trying to build a 6p turbo, which will probably need to be pretty far forward. Then modify a downpipe to reach.

Thanks for any ideas.
Old 07-04-14, 10:01 AM
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Pretty much all of the top quality manifolds are fabricated using GTAW (TIG). This allows for more precise control of the weld process, but also requires more skill.

It's not rocket science, so most people can learn to do it, but It does take some time to master.

spend some time researching the welding thing. look at

weldingtipsandtricks.com
Weld.com
Welding Web

search the sites, watch videos, ask questions from pros. make sure you know what you need to know.

I think you could use the GMAW (MIG) process as well. But, make sure you know you stuff. I've seen a number of people who thought they could weld with mig because they could stick things together. but when those welds are put to the test with a load in a high vibration environment, it suddenly becomes evident they couldn't.

Have a look at the welds from any of the top fabricators and it is obvious that they really know what they are doing.

I hope I'm not sounding too harsh, but it would be a shame to invest so much money and effort to build a manifold that could end up being no more than scrap.
Old 07-04-14, 06:17 PM
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most heavy duty turbo manifolds are going to be anywhere from 11 gauge, sch 10, or sch 40 piping.

I don't see a problem just using mild steel, or stainless mig welding. You would really just have to know what you are doing.

Most manifolds are purge welded.

You would also really want to chamfer between the joints so you can get good penetration.

If you are an inexperienced welder, I would honestly just go with one of those cast iron manifolds everyone uses. Not the best flow, but nice and sturdy. Rotaries run super duper hot
Old 07-04-14, 06:58 PM
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Might also be an idea to tack weld every thing yourself and then get a proffessional to weld it all up
Old 07-06-14, 06:59 PM
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i have made a few manifolds with must mild steel, 11ga tubing with no problems. i am really shitty at welding, so its not pretty but works. using 180A mig welder with gas. the hardest part is cutting/fitting the tubing. then there's actual design, huge affect on performance.. wastegate placement, tubing length diameter, angle
Old 07-12-14, 10:43 AM
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This video may help. In in, I weld up a 13B turbo manifold for my '76 Cosmo:





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