Header off from Modified race engine. PICS

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Originally Posted by A_Harman
Constrained thermal fatigue. It will crack again in the heat affected zone adjacent to the weld repair.
^ This right here guaranteed
 

tig1

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Originally Posted by A_Harman
Constrained thermal fatigue. It will crack again in the heat affected zone adjacent to the weld repair.
My customer has three dirt track race cars and I know him. If it breaks again I will pass that on to you. I actually have more confidence with this repair. My take is that the area passing by the bolt hole wasn't welded to begin with. Notice the other tubes. So I welded this one as you can see.
 
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Maybe you can oven bake the header at 400F to temper the heat affected zone and reduce the possibility there is Hydrogen embrittlement.
 

tig1

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Originally Posted by A_Harman
Maybe you can oven bake the header at 400F to temper the heat affected zone and reduce the possibility there is Hydrogen embrittlement.
Oven bake a header this size?? Lets not over think this.
 

tig1

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Originally Posted by Cujet
Slip joints are a great way to stop such cracking.
But that wouldn't help in this case.
 

tig1

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Originally Posted by ccs368
Is that weld bead going to cause issues with properly tightening a nut or bolt on that flange?
No, not shown in this pic was I ground out that area with a cut off wheel for the head of the bolt to clear.
 
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Don't buy cheap headers and this won't be a problem. I've installed so many sets of headers, shorty and long tubes and never had this issue.
 
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Jupiter, Florida
Originally Posted by tig1
Originally Posted by Cujet
Slip joints are a great way to stop such cracking.
But that wouldn't help in this case.
I do believe it would solve the problem. Such cracking is created by stress. The use of slip joints eliminates the high stresses created by thermal cycles and vibration. I deal with aircraft exhaust and race car/turbocharged engine equal length headers all the time, and see the same type of problems over and over. The slip joint is the solution. Quiz: Which pipe cracks in the picture below? [img]https://resources.globalair.com/images/article/a0750130-6.jpg?w=650[/img]
 
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tig1

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Originally Posted by RazorsEdge
Don't buy cheap headers and this won't be a problem. I've installed so many sets of headers, shorty and long tubes and never had this issue.
My customer races three cars on various dirt tracks, including Tri City Speedway in Granite City,Il. This didn't happen to him until it happened.
 
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13,102
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North Carolina
Originally Posted by Cujet
Originally Posted by tig1
Originally Posted by Cujet
Slip joints are a great way to stop such cracking.
But that wouldn't help in this case.
I do believe it would solve the problem. Such cracking is created by stress. The use of slip joints eliminates the high stresses created by thermal cycles and vibration. I deal with aircraft exhaust and race car/turbocharged engine equal length headers all the time, and see the same type of problems over and over. The slip joint is the solution. Quiz: Which pipe cracks in the picture below? [img]https://resources.globalair.com/images/article/a0750130-6.jpg?w=650[/img]
I'm going to say the one in the middle.
 
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