Anyone had luck welding OEM headers
10-14-2008, 10:22 PM
#1
Burning Brakes
Thread Starter
Anyone had luck welding OEM headers
I believe I have an exhaust header leak, but before I pull them I want to make sure I have good ones to put on.
I had a couple of 4-1's and a 2-3. All looked perfect, but just to be sure, I made up a simple pressure tester.
From exhaust pressure testing I have done in the past, pressure in the manifold is up to 25psi, so I figured 20psi or so would be a reasonable test pressure.
The 4-1's tested just fine, but the 2-3 showed a leak on the #3 flange to the cyclinder head. On inspection I could see a hairline crack approx 1/2" long.
I didn't want to weld it up, as my experience over the years is that its hard to stop them cracking again, once the cracks there.
So I go in search of a 2-3 manifold. I now have 8 of the stinking things, and I am yet to find a leak free one. They are either cracked at the flanges or at the Y weld or both. I have just about given up ever finding a leak free, unmollested, non welded one.
I figure I'll take the best one I have and have it wleded.
Has anyone had any long term success welding up the headers. If so how did you do it?
The best way to stop a crack is to drill the ends, and then prep the weld, but that's not easy when its the head flanges.
Another approach is an aftermarket, but I am concerned they will be no better. The Porsche design is very elegant.
I had a couple of 4-1's and a 2-3. All looked perfect, but just to be sure, I made up a simple pressure tester.
From exhaust pressure testing I have done in the past, pressure in the manifold is up to 25psi, so I figured 20psi or so would be a reasonable test pressure.
The 4-1's tested just fine, but the 2-3 showed a leak on the #3 flange to the cyclinder head. On inspection I could see a hairline crack approx 1/2" long.
I didn't want to weld it up, as my experience over the years is that its hard to stop them cracking again, once the cracks there.
So I go in search of a 2-3 manifold. I now have 8 of the stinking things, and I am yet to find a leak free one. They are either cracked at the flanges or at the Y weld or both. I have just about given up ever finding a leak free, unmollested, non welded one.
I figure I'll take the best one I have and have it wleded.
Has anyone had any long term success welding up the headers. If so how did you do it?
The best way to stop a crack is to drill the ends, and then prep the weld, but that's not easy when its the head flanges.
Another approach is an aftermarket, but I am concerned they will be no better. The Porsche design is very elegant.
10-14-2008, 10:40 PM
#2
Drifting
Join Date: May 2006
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well as it is near the head you can clean both sides plug in up perge the gas in and if just a crack fuse it back together .
the cracking is generally cooling to fast so your best chance obviously pre heating the in tire thing before the weld and perhaps post weld .
I've welded a baffle in one of mine and i got no cracks and i was rough and slack no preheat or such but i guess it could still crack
the cracking is generally cooling to fast so your best chance obviously pre heating the in tire thing before the weld and perhaps post weld .
I've welded a baffle in one of mine and i got no cracks and i was rough and slack no preheat or such but i guess it could still crack
10-14-2008, 11:27 PM
#3
Drifting
Join Date: Dec 2002
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purge with argon and tig weld and you'll be fine - mine were cracked completely around pipe #2 right above the weld where it joins #3. It's been 2 years and hasn't re-cracked and the car has seen the track during the summer
