cracked header

[rwy95eclipse]

runing a stainless header and it has cracked for the 2nd time any one know whats going on with that?

 

[stocker97tsi]

Normally, aftermarket headers are made of thinner metal. The heat from the motor causes them to crack or break more often..how long have you had it?

 

[Locke]

Make sure you are using a flex section, that the rest of your exhaust system is properly mounted, and that your motor mounts are in decent repair.

Otherwise, stocker97tsi is correct, tubular headers are inherently weaker than the factory cast manifold.

 

[BigRand]

runing a stainless header and it has cracked for the 2nd time any one know whats going on with that?

Well, what kind of stainless steel header? Is any part of it heat wrapped? (it will cause it to be more prone to cracking). Is it a 4-1 design or a 4-2-1 design? If its a 4-2-1 design what kind of flange connects the upper a lower parts?

 

[My1GLaser]

What brand header are you running? I had a $150 ebay one that cracked in 1 mo. all the way around runner #4. Some good headers last for years, but cast takes the heat better because of its thickness. Now, if the SS header was 1/4" thick tubing it would last longer...especially if I welded it.

 

[gsx951]

Clean it REALLY well INSIDE and out before you give it to someone to weld. Carbon ruins stainless steel by forming carbides with chromium when it gets hot. Weld it with 308 or 309 filler.

 

[rwy95eclipse]

about 1yr

 

[rwy95eclipse]

Well, what kind of stainless steel header? Is any part of it heat wrapped? (it will cause it to be more prone to cracking). Is it a 4-1 design or a 4-2-1 design? If its a 4-2-1 design what kind of flange connects the upper a lower parts?

its a 4-1 custom built header the top is wrapped

 

[rwy95eclipse]

What brand header are you running? I had a $150 ebay one that cracked in 1 mo. all the way around runner #4. Some good headers last for years, but cast takes the heat better because of its thickness. Now, if the SS header was 1/4" thick tubing it would last longer...especially if I welded it.

what would be a good header to run with my setup

 

[WarSaw]

It looks like you are talking about a turbo manifold rather than an exhaust header judging by your profile information and pictures. The same reasons cause the cracking though, thin metal, no flex section, poor welds, etc.

An option to fix this is a cast manifold such as the Star style manifolds. You might run into fitment issues with your downpipe when switching manifolds.

 

[gsx951]

what would be a good header to run with my setup

Forced Performance: FP DSM Race Manifold

I've built 120 tig welded turbo manifold assemblies for a major OEM that have gone through cyclic heat testing on engine dynos with the failed parts submitted for complete engineering analisys. What the experience taught me is that the mechanical characteristic of the tubing completely change at high tempurature. Steel, even 304 stainless, becomes very weak at the EGT we run. The combination of high heat and carbon in our exhaust, attacks the material and alters it's metalurgical structure. The result is corrosion between the actual grains in the steel and the formation of cracks. Add some stress from a turbo hanging off of it or a downpipe with no flex, and you are certain to have issues.

If you want a tubular manifold, there are only two workable solutions:
Use a "stabilized" alloy such as 321 stainless steel. (huge money)
Use "weld els" like you see commonly in a Ron Shearer manifold ::ShearerFabrications.com - Products::

For the rest of us, there is the Shearer designed FP manifold

 

[rwy95eclipse]

ok thanks for all the help

 

[Shadow98]

From looking at your pics, I'd have to say that the heat wrap is causing it to rust (hence the cracking).