I have a backup set of /6 headers that have some dents. The dents are on the curved areas. I am sure that air flow would be reduced with these dents. On one of the dents, I drillled a small hole on the opposite side, heated the pipes, stuck a small solid metal rod through the hole and tried to pound out the dent. I was able to remove the debt however the area is now fairly rippled. I don't think I can flatten it would more without making a bigger hole which would be much more difficult to weld shut.

The ripples are not horrible however you can definitely see them. Should I just leave the ripples or is there some other way to fix the issues? If it were on a straight pipe, it would be easy to weld a new pipe in its place however not easy on the curves.

post pictures.
often times the small dent will do almost nothing performance.

The two debts arrowed in red are the problems. I'm not worried about the green one since it's on a straight. I can fix that one.

Dent puller.

I would us a torch and a rod slid down the pipe to push It out. Or cap the opening and put about 125 psi of air in the tube and heat it with a torch. It may expand. Just be ready to cool it off so it doesn't blow out the tube.

https://www.motortrendondemand.com/detail/e...ts-/0_ujj8a8mw/

Those dents wont make any notable difference.

Wow. That very surprising.

So the secret in the exhaust industry is to cap the ends and pressurize the tubing to about 10psi. Then heat with an oxy torch and the dents will pop out..

I have don't this tons of times and have done it On front oil cooler lines for 911s many times as well.

So mandrel bent versus cheaper header construction? No difference? Really surprising given the amount of marketing and premium prices associated with mandrel bent headers.