A while back, I lost my old cell phone that had some interesting pics. I since found that phone and was able to get the pics off of it. What I want to share with you guys is a picture of what I feel is a poor combo when it comes to headers.

Back a few months ago I replaced a set of headers. with our header system. After removing the old headers. I noticed a crack in the header where the primary meets the flange. You can't help but ask yourself.. "why did this header crack?"

So here is my take as to why this header failed. In the pic below you will see the inside of the port where the header meets the flange. On a 63 the ports are oval. trying to fit a round tube inside an oval port presents some challenges. If it isn't done right you get exactly that.. Round tube in an oval port. What happens with this is, you get transition areas on the sides of the port where the oval shape will turn into a round shape. When this happens so close to the head those transition areas get extremely hot from being in the direct line of fire from the exhaust ports on the head. If you compound that with mild steel.. It will fail 9 times out of 10. I would even suspect stainless steel would fail with this design. Maybe not as soon as mild steel, but I think it would over time. Keep in mind, mild steel's inability to expand and contract due to its rigidity, will most always result in cracking if designed like this. Over time The crack would have only gotten bigger

If you want to know, I have no idea who's header this is. What I do know its it is made of mild steel and the coating was coming off. In fact it was all over my hands, just from touching it. Who knows? It might have even been BBQ grill paint.

Anyways, just some food for thought when thinking about headers.

 

Very interesting and informative! After reading that first line - I thought you were going to warn everyone that if you don't wan't "interesting pictures" getting out on the internet - don't keep them on you phone.

 

Tell me about it, My phone was inside a box in my garage. How it got their? I have no idea.

 

Rule #1

 

Did the car have any flex sections in the exhaust? In my opinion that is a must , sure you can over build the header to the point where it isn't necessary but if someone goes cheap on the headers, alot of time can be bought with a couple cheap flex pieces. On some higher power turbo vehicles I've owned that is the ONLY way to keep even the most expensive tubular manifolds from eventually cracking.

 

Your points are valid, also may not have properly back purged during the welding peocess leading to the stainless becoming brittle right?