Keeping headers from cracking

How do you guys keep your headers from cracking on a BAE blown Hemi. Currently I build them out of .065 and after a while they crack at the flange coming out of the head. These are not zoomies they are under frame headers that collect into 1 and come out the side on a 10.5 car. Ive tried supporting them and not supporting them, welding gussets from the flanges to about 1.5 inches down the pipes. Any input would be appreciated.

 

Get yourself a thermal sick from your welding supply,this depends on the temp which you need. Rose bud the joints (stress relieve) use the stick to achieve the given temp.The problem is the welded joint is too brittle,you must bring the joint back to where it was before welding.Hope this helps,DAVE

 

What rod are you welding with? If steel rod try a silicon bronze it will work better.

 

Moparchris check your pms.

 

Hahaha. Now that's priceless. I have found by squishing the tube down and forcing it inside the flange , takes some work but if you do that and then mig weld, yes mig weld the flange on the outside and use the tig torch and weld the inside of the flange I have gotten about a years worth of runs before I seen cracks. However you should be looking every weekend after racing for cracks. These are violent machines in the 2 step , everything fatigues over time.

 

mig mig mig !!!

we had a set of headers that we thought we were going to have to replace that were tig welded at the flanges and cracked almost every time we too it out we kept having them retiged each time last year in a rush to get to the races we took one off and mig welded it where it had cracked so now we have one side miged and one side tiged so over the winter i pulled them off and checked them for cracks and built braces for them that hooked the tubes together as well as to the chassis but left the flanges alone.....first time out guess what the tiged side broke loose again but the mig side was great so we took the tiged side and mig welded it and wala if any of you were at tulsa you can attest to the fact we shook as fiercly as it gets and no cracks my opinion is that a tig weld dosent connect enough area between the tube and the flange

 

Tig

My Chevy stainless set never cracked at flanges but everything else broke. I adapted mild steel flanges for bae and used silicon bronze with big fat beads...haven't hit it yet.

 

I have a few ideas i would like to try including .083 wall tube for the first 4-6'' maybe 4130 flanges different bracing.... looking for a Ginny pig lol