Cracks in S4 turbo
11-13-11, 02:19 AM
#1
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Cracks in S4 turbo
Hello,
Just purchased a used S4 turbo and manifold. I noticed some cracks around the turbo exhaust inlet ports. Has anyone ever tried to weld this area ??? I also noticed (since the guy had several manifolds on hand) that each exhaust mani had a crack in the same area (the outer area close to the turbo flange).
Any info will help...Thanks...
Just purchased a used S4 turbo and manifold. I noticed some cracks around the turbo exhaust inlet ports. Has anyone ever tried to weld this area ??? I also noticed (since the guy had several manifolds on hand) that each exhaust mani had a crack in the same area (the outer area close to the turbo flange).
Any info will help...Thanks...
11-13-11, 10:18 AM
#2
Engine, Not Motor
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Very common.
A few small cracks around the divider between inlets aren't going to be a problem. But if the cracks extend deeply into the flange, the turbo will tend to blow out gaskets.
Welding is possible but is complicated. The housing needs to be media blasted, then baked to remove as much contamination as possible. The casting is a high nitrile casting so the appropriate filler is 316 stainless. The casting must be brought up to temperature as a whole, welded, then slowly allowed to cool in an oven to prevent cracking. Then the flange must be machined flat.
Not worth the trouble in my opinion unless you have the time and equipment, or know a friendly welder.
Cracking on the manifold is common as well. Especially on the stud that sticks out into the flange near the runner. Small cracks are OK, but again, large cracks will blow out gaskets.
A few small cracks around the divider between inlets aren't going to be a problem. But if the cracks extend deeply into the flange, the turbo will tend to blow out gaskets.
Welding is possible but is complicated. The housing needs to be media blasted, then baked to remove as much contamination as possible. The casting is a high nitrile casting so the appropriate filler is 316 stainless. The casting must be brought up to temperature as a whole, welded, then slowly allowed to cool in an oven to prevent cracking. Then the flange must be machined flat.
Not worth the trouble in my opinion unless you have the time and equipment, or know a friendly welder.
Cracking on the manifold is common as well. Especially on the stud that sticks out into the flange near the runner. Small cracks are OK, but again, large cracks will blow out gaskets.
11-17-11, 12:56 PM
#5
Senior Member
U should also 'radius' (rounding all the 'sharp' edges off will relieve stress & prevent cracking) the inlets/outlets w/a dremel or die-grinder.
11-27-11, 12:59 PM
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Ok,
Thanks for the help, I will do my best to weld up the mani first. Since I might be building my own mani later, it's worth a try. I'll also radius the sharp edges as well since I'm porting the waste gate...
Thanks for the help, I will do my best to weld up the mani first. Since I might be building my own mani later, it's worth a try. I'll also radius the sharp edges as well since I'm porting the waste gate...
04-12-12, 01:13 AM
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Welded the manifold using 308 filler rod & TIG'ed it, I hope I did the cool down slow enough to prevent further cracking...
I ported the waste gate, I'll get pic's on it ASAP...
I ported the waste gate, I'll get pic's on it ASAP...
