.005" wastegate flange gap/warped

[GSLENK]

My o2 housing wastegate flange is warped. I used a feeler gauge and it is right between .005" and .006" only on one side, the opposing and orthogonal sides seal fine. I first bought a set of multi layer SS gaskets with fire rings. There is still that gap when torqued down (also the gap is on the wastegate fire ring, which lead me to believe the flange is warped).

I can file it down a bit to get it to about .004-.003 gap. Anything else I can use to finish it off? Ultra copper RTV? Copper spray?

I swear I read something about a maximum gap for each, any ideas?

Should I even use gaskets? or just try to seal it with rtv?

 

[bryanwheat]

About the only thing that is going to seal it is a composite gasket. IT won't last a real long time with a warped flange though. Copper spray and rtv will last a few days at the most. The best bet is to find a machine shop that can resurface it.

 

[pauleyman]

5 thou? I think I would block sand it. We arent talking about a cylinder head.machine should probably wouldnt mill that unless you asked them to. Would likely belt sand it.

 

[GSLENK]

Just need something to hold me over for now (a few months hopefully). The current o2 housing is a pos. It has a stainless flange welded to it (its mild steel btw). I suppose when it was welded, it warped convex (think hotdog style fold, not hamburger style). My table top belt sander wont clear the other flange (recirc o2 housing). I just filed and block sanded it. Took forever but its close enough, if not, its coming off again and going to the bottom of a river.

Also machine shops suck around here, or I am not looking hard enough.

 

[GSLENK]

UPDATE: Well I went ahead and bolted it back. I sanded it by hand for about an hour. Its still in the ballpark of .003 and .005. I think I could fit the .002 feeler and wiggle it 2 cm total from one side extreme to another.

I used some copper RTV, laid it on really good. Assembled it most of the way. Torqued it all down about 45 minutes later.

LEt it sit on the car 24 hours, and started her up. NO LEAKS!!!!

Been that way for about 2 weeks now. Hope it stays that way . if not... I need an MVS.