SOR Header Flaw??

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Feb 27, 2012
San Antonio, Texas
Hey Ladies and Gents,

Reference the pic...
New headers from SOR just came in today, they seem to be warped pretty this normal?
Or do I have headaches and long nights ahead of me?

Going on a 03/72.
Thank you!

Would be a problem if that was an OEM cast manifold - but it's not.

In other words, those flanges should bolt-down true and leak-free. (It should twist into place when the nuts on the studs are tightened.)

To CYA, I'd contact SOR and get their opinion. Just in case you have a problem down the road a bit... Although I'm sure lostmarbles is correct.
Well at least they have nice thick flanges. I would bolt them up and see what happens. If they start out leak free they look like they are high enough quality that they will stay that way. You could always have them machined flat. I paid $50 to have my manifolds done.
Be sure to use either a copper or aluminum header gasket and you won't have leak issues.
that'll be sweet mate it'll all pull up nice and tight, if it was one single flange plate across 6 exhaust ports it would want to be in a constant flat plane, that's the preferred way for exhaust flanges to be constructed (multiple independent flanges) to allow for heat expansion and movement minimising the amount of distortion across a single long flange
Lostmarbles is correct. Shorter flanges do not warp as much from the heat of cutting them into shape, longer flanges (straight 6 engine) warp more from heat during the cutting process. Those warped flanges easily pull into the head when tightened, in fact I've pulled them snug against the head with finger tight pressure only on the mounting nuts (even before wrenching). The real trick here, no matter which gasket you choose, is to apply "paint-on" Copper Coat onto all four surfaces, head-header-both sides of the gasket, then tighten until you think your wrench is going to break. Copper Coat is lacquer based, so unlike other adhesives that melt and run like water when heated, Copper Coat bakes-on with heat. Spray-on Copper Coat is watered down, use paint-on.
I'll bet you could flex that flange back true just twisting by hand. Temporarily of course but it would prove the points made above.
Thanks for your comments guys. I'm not sure its going to flex as easily as some might think though. If your not familiar with these SOR headers, they are two solid plates about 10.5-11.00 mm thick.
Here's another pic, you can kind of see the full plate that goes across these pipes.


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I think the advice above assumed they were independent flanges. the new photos are a bit more clear, they are connected. Contact SOR. I wouldn't be comfortable trying to draw that 1/16"+ out of almost 1/2" plate.
Have to agree with mdsims. You'll be transferring a lot of stress to the threads of the fasteners that'll be constantly trying to release. If you like torquing bolts to some sort of spec, that'll be out of whack too. I see leaks in your future.
... then tighten until you think your wrench is going to break. ...

Old school thinking, but almost always poor advice. Fasteners have a yield point. Tightening them past that greatly weakens them, actually reducing clamping force and will continue to stretch, loosen. It's best to torque them to spec, or the max allowed for the fastener.

Pulling them into shape will over compress parts of the gasket, and under others, making it more likely to leak. It's likely that the warp is from welding the tubes on, doesn't matter, should have been pressed out/corrected at the factory. This is just one of the reasons that I prefer not to run headers, 3FE manifolds work well and are much less likely to leak.
Kevin, I wouldn't argue with the technical aspects you have mentioned, but in practice what I mentioned has always been a remedy, and we've always gotten away with it since the mounting nuts are a softer metal than the mounting studs- - - just saying.
Appreciate all the input fellas.
I emailed SOR's tech. and customer service and attached the pics. We'll see what they say. Weather they say they are within some specs or not, in my opinion, they should be QC'd better. I don't want to machine them out b/c then I'll loose the thickness of the flanges which would then (possibly) lead me to shimming out the bolts to have even pressure on the intake and header.
I think the advice above assumed they were independent flanges. the new photos are a bit more clear, they are connected. Contact SOR. I wouldn't be comfortable trying to draw that 1/16"+ out of almost 1/2" plate.

Yes I did assume they were independant flanges.. so I now take back what I said before.

The warping does concern me now...

To bolt them up true like this I think you'd have to cut them into four separate flange plates.

:hmm:I wonder why the manufacturer didn't do this anyway ... because such warping was predictable .... and why add all that unnecessary weight by linking the flanges?

But cutting them now is not ideal considering their pretty coating? I'm interested in SOR's response..

I went through chasing a leaking header recently. After much frustration, I ended up buying a JT outfitter header. I had it machined and installed it according to Downey's suggestions. Worked out fine. Of course I haven't actually driven the rig, as I am still putting the rest of the 40 together. Listen to Downey, he really steered me right.
Because of the intake and exhaust sharing the same nut i have always machined the intake and exhaust to the same thinkness. Better chance of not having to chase leaks latter. If the intake and exhaust are different thickness odds are they wont tighten the thinnest piece. Whatever downey says is what i would do he has done it more times than most of us.

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