any way to straighten mild steel log manifold
 

had a freind who I thought new more than me weld up my parts. now the two center flanges do not sit flat, but are almost 1/8" up when sitting on the counter.

any way to straighten it out post welding? at least to get it straight enough to face it and not loose half the flange thickness

I've had suggestions of bolting it down to a junk head (which I have, but it is aluminium) and heating it with a torch. how hot should I get it? acetyline right? I have a hard time thinking I could get it hot enough with the head sucking the heat out.
I also have access to a vacuum oven that is big enough to put the head and mani in

Re: any way to straighten mild steel log manifold
 

scrap pile and start over

about a month of sundays on a big belt sander

40 bucks at a machine shop


just don't try to muscle it down on the head, you will strip a exhaust stud. i know, because i did it on my first manifold i made

Re: any way to straighten mild steel log manifold
 

40 grit belt and go to town.

Re: any way to straighten mild steel log manifold
 

1/8" is alot. cut the two inner runners down by the warpage amount, bolt the flange flat, and finish it on a beltsander.

Re: any way to straighten mild steel log manifold
 

how thick is the flange? just surface it, not like its gonna warp again so who cares how thick it is. ive seen flanges get as thin as 1/4" and still work

Re: any way to straighten mild steel log manifold
 

if you mill it back flat - the grainular structure of the steel will still be its original form. It will continue to pull apart. If you torch it real hot and bend it back down the flange itself will be ok. The problem now is that everything else was welded into the wrong position, and its grainular structure is pulling that direction and will likely pull itself apart trying to fight the now correct flange.

this is assuming it doesn't pull the studs out of an aluminum head, or snaps a low quality stud/nut/bolt whatever.


in a bad case you should toss it.

Re: any way to straighten mild steel log manifold
 

so, cut the high spot out of the center runners, bolt the flange down, and reweld them more straight to grain, or just mill the flange for 2 hours on a beltsander?

Re: any way to straighten mild steel log manifold
 

post a pic, it will be easier for us to know how to fix it if we can see it

Re: any way to straighten mild steel log manifold
 

it depends on how bad it is. I mean there's workable and then there's omg that's a good first effort to learn from that failed!

what i would do, is take whatever sections you want to call the bad and cut it off on the pipe. Bolt all of it down and weld the gap up. when welding back together tack it GOOD, and skip weld opposite sides. get a pair of welds together and take a break for a min to keep it from heating and expanding like a mofo.


it really needs to be bolted down. clamped if you have too but if you get it as hot as you did to warp it again itll just pull off the clamps

Re: any way to straighten mild steel log manifold
 

vice, file, straight edge
iv done it 2 times now (cast iron flange warps once in a while )