Captain Bondo

And actually having any luck in terms of durability?

I am helping out a shop building some headers for them- largely because they have been having cracking issues and are behind on production.
The catch is, they already have a ton of 16ga material and don't particularly want to scrap it.

So at least for the first run I do for them, they'll be 16ga. :P

These will be welded for 100% penetration, fully backpurged, and the wastegate pipes will be braced. In other words I am going to do everything I can, but I like to "prove" a construction method before I sell parts.

The shop knows this so my *** is covered from a liability standpoint, but it's still my work and my rep to some degree.

My feeling is they can certianly be built to live through a couple years of abuse- but I just don't see them having the longevity sched 10 has.

Any thoughts? I am looking forward to working with somehting different. SHould be fun.

mandrel-bends

We build a lot of non honda turbo headers in 16 gauge. Most of the failures are typically at the collector welds. Our solutions is to use ER 347 tig rod w/ a full back purge and bracing. One particular turbo setup that we've produced hundreds of for 4 years has had a near 0 failure rate once we switched the ER347. When we were welding them w/ 308 we had significant failures for the first few months (couple sets a month).

Captain Bondo

Neat on the 347. I use 309L on my sched 10 stuff using the same reasoning- overmatching the properties even more will help reduce intergranular corrosion and make things a little more "forgiving".

These failures were collector related as well (wastegate pipe I think). Where the heck do you buy 347 rod? I have looked into a couple projects using 321 and I had a hard time locating any. Wanna sell me some? :P

mandrel-bends

We special order it. I can sell you some.

gon3r

i did a manifold out of 16g mild a few years ago and it didn't have any serious issues.

Captain Bondo

Sweet, you rock. I'll email you tonight. Thanks man!

Minor Threat

FWIW my top-mount is built out of 18ga Hooker mild steel U bends, and it's migged, no issues yet.

Toysrme

If you're really worried about it grind the flashing down until it's the nominal pipe wall tickness, then do a full-pen weld on the collector with backside root reinforcement. Done a couple, not a big deal just more sensative to squareness, stress & irregularties in the welding than alot of people want to deal with. schedule-10+ is just so much overkill alot of things dont show problems for so long you wont know it that would show up on the thinner pipes.

jinxy

What are you talking about? How are you going to "grind it down" and make it pipe wall thickness?

Captain Bondo

Thanks Toys- I've got what you're saying. Aaron- I emailed your re: 347.

What Toys is explaining is when you cut the collector pieces and but the together, right where they join it's almost like haveing a roughly 1/2" thick joint.

If you stick the pieces together and mark the weld seam with a sharpie and then take them apart, you can tell what material "behind" the seam is "extra".

It's hard to explain. That's probably a good idea- that's sorta my thought- fit everything perfectly and backpurge welding full pen- so theres reinforcement top and bottom. Should be ok.

It will be more fiddly than sched 10 becuase the fitup will need to be more precise, but the flip side is that the thinwall is easy to trim up, fast to cut, and fast to weld. Also it's U-Bends so there will be less welding than I'm used to having to do with sched 10.

So, I'm hoping overall it won't really be more work than the sched 10 I'm doing now.

I've basically told the shop though that I'd prefer using sched 10 once the 16ga they bought has been used up if I build stuff for them in the future.