[Chevy86 IROC-Z]

Hows it going guys. New guy here. Im taking Welding in my community college. Today will be my first day learning how to weld using the TIG. I want to add filler metal to my exhaust headers. The section where the bolt goes in the cylinderhead is pinched by the manufacturer. So I want to add filler to be able to grind away the inside of the primary tube to enlargen the exhaust port. The tube is 16 gauge and is steel. What settings should I use for the TIG welder (amps, DCEN,DCEP, filler rod, volts, post flow)? Thank you in advanced.

[cj737]

I'll offer you some opinion and advice based upon observations:

Amps needed will be low. I just welded 16 gauge sheet yesterday and used between 20-40 amps on my foot pedal. I used a 3/32 tungsten with about 13-15cfh, postflow of about 8.5 seconds (more than needed).

Your objective is dicey. To buildup enough metal outside to allow the grinding off from the inside will possibly put your OD in conflict with the exhaust stud/nut. Best check that pretty quickly. To add that much metal with thin rod (you'll use 1/16-3/32) will require numerous passes. As a new TIG welder protecting from overheating the tube, you are apt to embed porosity. Then grind into it from the interior, creating exhaust leaks. See where I am headed?

I understand your objective, but I am not sure you can achieve it with that tube, manifold, and a TIG or MIG welder. You can certainly add material, and remove from the interior, but you need to be cautious about conflict and grinding through.

Hope that helps?

[Oscar]

Won't you lose valuable clearance for the bolt head by adding that material to the outside of the header tube?

[sedanman]

Hot Rod did a dyno test on dented headers, you are not losing any power whatsoever with that little "restriction ".

[Rick_H]

Been there done that....no gains. I built engines for some class race cars and we tried everything..lol You'd benefit more from having a little straight coming out of the flange before it hits the turn, but that means new headers. Welding on headers that have already been run in never fun..lol you'll need to get it very clean and even that you'll end up chasing it in most cases, even good headers I've fought porosity.

Youll need to run a stud and a small headed 12pt ARP nut on the outside if you really want to modify it.

[Oscar]

Hot Rod did a dyno test on dented headers, you are not losing any power whatsoever with that little "restriction ".

I agree. Exhaust flow, especially right at the cylinder head exhaust port, is anything but laminar. 100% turbulence won't care about that tiny dent. It's even aerodynamically shaped,

[rick9345]

Chassis tuning and tire work,will show more results than header dents.