Header flange is warped, best way to mate to the head??

[Ski-Dooin' it]

Just fyi, its a 1 ton motor, so its a pretty long flange. When I built my new header this summer, the flange on the motor side had a TINY big of warpage to it.. even with a good straight edge, over the whole length the thing the out of straightness is `1mm at most. When I I installed it I copper gasket sprayed the chit out of both sides of the gasket, and it seemed to seat well and not leak. now after riding it a few hundred miles im noticing that there is black all around the edges of the exh ports at the header gasket. it also obviously blows steam out when its starting in the cold. I pulled it off and was curious what the best way to remedy this is??

Could I double up 2 gasket without risk of blowing them out?? Right now until i either descide on another gasket, im just gonna load the copper spray on nice and heavy on the gasket and mating surfaces and reinstall, but I was curious of a more permanent solution, if this one isnt. A new header would be nice, but at around $250 in just materials to build one, no thanks.

And while your reading, would a leaky header lead to a lazy out of the hole and boost fading under load?? seems like what I read, but just curious.

thanks guys

 

[DV8]

I would take it to a machinist and have them mill 1 mm flat. then use 1 copper gasket and your good to go.

 

[dirk_03]

Take it to a machine shop they should be able to machine it flat for you. The header I made I surfaced on a manifold surfacer. But I think it could be clamped to a bridgeport and milled with a fly cutter or a face mill as well. Shouldn't really cost to much to have done I wouldn't think and it will save you alot of headaches.

 

[Ski-Dooin' it]

ohh.. i forgot about milling it.. I should ask at school if someone could do that.

and yeah, thats definately a good solution to my problem.

good htinkin guys, my brain was in the wrong mode.

 

[mbarryracing]

Yeah, see if you can get it ground flat first. But, how thick is your flange? As thick as the stock manifolds?
If it's too thin, it will be suceptible to warping again due to the additional heat of being turbocharged. Could be inherent in your flange design.
Most OEM's don't use one long flange for this reason, they mostly use individual flanges to accomodate thermal expansion, etc.

 

[DV8]

Yeah, see if you can get it ground flat first. But, how thick is your flange? As thick as the stock manifolds?
If it's too thin, it will be suceptible to warping again due to the additional heat of being turbocharged. Could be inherent in your flange design.
Most OEM's don't use one long flange for this reason, they mostly use individual flanges to accomodate thermal expansion, etc.

This is a good point. If its to thin it will just warp on the first ride. If its the stock one 1 mm isnt to bad you should be ok.
What header do you have?

 

[kinger]

Would it be stupid to cut the flange between every cylinder so it could individually seal each port, then use stock yammie gaskets?

 

[mbarryracing]

That would not be stupid, it might be stupid NOT to...
Metals do weird things when heated, plates walk all over the place when you weld on them. This is no different...

 

[Ski-Dooin' it]

Mine is a half inch thick flange from powderlites. so its got no shortage of girth, just when I rebuilt the header this fall, my buddy did the tig welding and forgot to clamp it down when he did, so it got a tiny bit wabbled.

so my thought is that the only reason the turbo guys use big single flanges is that it allows for the ease of building/placement of everything and holding the bolt holes all up to par as im betting welding tubes onto individual flanges would suck pretty bad. IMO, having 4 single flanges would allow a tiny bit easier flexing and better seating. but who am i to know this stuff.