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Header flange broken!

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Old 02-20-2019, 09:37 PM
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Default Header flange broken!

I replaced my warped factory exhaust manifolds with a pair of stainless shorty headers a few years ago. Lately, I have thought I heard a slight exhaust leak intermittently. I sort of dismissed it, since it was intermittent and small. Monday, on my way home from work, it stopped being intermittent, it suddenly got quite noticable. I figured a header or collecter gasket, but couldn't see anything. Crawled around under the truck for a while and finally concluded it HAD to be a header gasket, though I never did see anything. Gaskets and bolts arrived today from Summit (stainless, ARP bolts, since the existing ones are such junk - the heads are rusting off of them) and I unbolted the header flange from the head. Not without some difficulty because of the aforementioned bolts.

Once unbolted from the head, the freakin thing came right off because it was broken off the collector flange! I am not real impressed with this, as you can imagine.

The flange bolts are in pretty sorry shape, too, and so far, don't want to come out. But at least they're easy to access with the rest of the header out of the way! WTF!

I guess once I get the flange bolts loose, I'm going to secure them enough to maintain the proper flange position; then bolt the rest of the header back to the head, and tack weld the flange back in place. Then I'll take it somewhere to get it properly TIGged.

That is, after I extract the remains of the broken bolt from the head...

What a freakin mess!
Old 02-20-2019, 09:39 PM
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I'd just buy new headers, the tig welding will just crack again.
Old 02-20-2019, 09:50 PM
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Well.... The new headers will be TIG welded in the same place. Not being a smart-***, but why are new headers a better option than a competent TIGger? Who's to say the new o es will be any more dutable?
Old 02-21-2019, 03:55 AM
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Who made these to begin with? And being shorties I would just put the factory manifolds back on, find a used set cheap.
Old 02-21-2019, 09:49 AM
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I'm not going to get into what brand, etc, because after thinking about it, this could be caused by bad motor mounts, which I haven't checked yet.

used manifolds: Bad idea. Considering the common issue on these trucks of broken manifold bolts and warped manifolds, it's very likely that used manifolds will be warped and won't seal. Or won't last. That's the reason I went with the shorty headers to begin with.

Now would be a good time to go ahead with long tube headers and get it tuned. But, this is my primary vehicle; today is my 2nd and only day off for the next 17 or 19 or something days; so I want to get the damn thing back on the road. And I have to drill a bolt out of the head that broke off flush. As well as fight with the rusty collector flange bolts. So there's no time to screw around with "nice to have" items.
Old 02-21-2019, 10:53 AM
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I can tig up the damaged shorty if you need. PM me if interested. I'm pretty sure you live just a town over from me.
Old 02-21-2019, 11:11 AM
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Originally Posted by wretched73
I can tig up the damaged shorty if you need. PM me if interested. I'm pretty sure you live just a town over from me.

Message sent! Thanks for the offer, be glad to take you up on it if we are able to connect.
Old 02-21-2019, 04:10 PM
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They broke because they are probably 16ga thin SS headers and they just don't last. Thin SS gets work hardened after many heat cycles and begins to crank. Once they crack once, they will continue too even after you weld them. That's just life and what they do, especially the cheap Chinese ones. Factory manifolds usually last a very long time and replacements can be had for $60-90 brand new from ebay or Amazon. Those are what I have guys buy for turbo builds and I've never had one of them warp or break in all my years in the turbo biz.
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Old 02-22-2019, 03:34 AM
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These are definitely cheap SS headers. Supposedly 304 stainless. They've been in the truck for about 4 years and see pretty much daily service. Iive in NJ where the roads get heavily brined and salted at the slightest hint of snow, so they've been exposed to that for 4 winters.

All that said, they show quite a bit of oxidation and pitting, especially on both of the flanges (at the head and collector). This is my first experience with SS headers, but I expected better durability from SS. But, not really sure what's a realistic expectation for this material. In the old days, Blackjack were the cjeap headers. I bought used Blackjack headers and ran then for years - carbon steel with no coating. So I expected pretty long life from SS.

The collector flange weld is what broke. Tubing totally intact, it pulled right out of the flange. I welded the flange back on - MIG welded, after seeing all the rust. I figured if there's that much carbon in there, I could get away with MIG. If there's really 16% nickel in these headers, my weld will undoubtedly fail, but we'll see. It might outlast the pitted tubes.
Old 02-22-2019, 07:22 AM
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Originally Posted by kbracing96
They broke because they are probably 16ga thin SS headers and they just don't last. Thin SS gets work hardened after many heat cycles and begins to crank. Once they crack once, they will continue too even after you weld them. That's just life and what they do, especially the cheap Chinese ones. Factory manifolds usually last a very long time and replacements can be had for $60-90 brand new from ebay or Amazon. Those are what I have guys buy for turbo builds and I've never had one of them warp or break in all my years in the turbo biz.
And what thickness tube do you think the domestic header mfgs use??

I've sold hundreds of thousands of feet of stainless 304 tubing to header mfgs and 85% of it has been .049" wall thickness. One guy builds them for high end imports and uses .065" wall thickness tube. The guys building headers for domestic muscle cars use .049" in almost every application. I had one guy change one of the headers to .065" on one dodge application because the vibrations were too much and they cracked, so those were then changed to .065".


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