Header flanges for US Crossflow owners

['68falconohio]

Alright guys, I just finished up a model in Solid Works for the crossflow.
I have a source with a CNC Hi-Def Plasma table and I'm going to see how it comes out on 3/8" mild steel plate. I don't believe that his table will do a good job on 1/2" plate as plasma cutting leaves a taper that's more prevalent as the matl. thickness gets larger than the hole diameter.

I'm going to try one on 1/2" though for those wanting to turbo. If the 1/2" plate can't be fully cut on the table maybe I'll have him cut the flange profile and port holes, leaving the boltholes to be drilled on the drill press with a 3/8" plate as a jig?

I know of one FSP member who's interested in header flanges but is anyone else interested?

Once I confirm fitment on my head, I'll post some pics. I'll have pricing then; they should be quite affordable.

[MustangSix]

1/2" is kind of thick, even for a turbo application. 3/8" would be plenty, I think, and 5/16" would be sufficient for most other N/A uses.

['68falconohio]

It seems the consensus on theturboforums.com is that 1/2" is a good thickness for turbo flanges; that's where my thought came from. I do not have any experience with turbo motors, just offering up this group buy on flanges because I have a good contact with a CNC cutting table. I'm going with 3/8" thickness on my N/A setup so that I can hit the flange on the belt sander to true it up after welding. Hopefully I have some pics of a good fitting flange by the end of the week.

[MustangSix]

Don't get me wrong - 1/2" will work, but welding a 14 gauge or 16 gauge tube to a flange that thick will be tricky. That much metal takes a lot of heat to get any penetration. It'll take a good TIG operator to keep the heat directed to the right place. Other than that, I think it's just thicker than it needs to be.

[aussie7mains]

10mm is the norm down here, and I wouldnt tig weld either, the MIG is better for that, TIG is OK for the other pipe welds if you really must have a speccie job.
I always laser cut my flanges unless they are thicker than 20mm which is the thickest that can be cut with that process, (less in ally) thicker is water jet.
A7M

[MustangSix]

10mm is closer to 3/8". I would think a MIG on such dissimilar masses of metal would be even harder to do.

['68falconohio]

MustangSix, it's my understanding that most DIY turbo header builds are done using sched. 40 weld elbows and sched. 40 pipe due to the temperature and stress. 14 and 16 gauge mild steel won't live long w/out mucho bracing, AFAIU. If this isn't accurate, someone please let me know.


MIG will shine with dissimilar material thicknesses; torch angle and parameters adjusted accordingly.

If you're welding 1/16" material to 1/2" though, once fusion on the leg of the weld is greater than the thinner material's thickness failure is forced into the base material. To qualify a welder for Sheet Metal welding to AWS standards, they have to weld the sheet metal to a 1/2" plate in a T-joint configuration. By far one of the easiest tests because it's super easy to get 1/16" of fusion on the sheet metal and force the failure into the sheet metal.

I'll be TIG'ing mine.

Still havn't had a chance to drop by my buddy with the plasma table, hopefully tomorrow.

[MustangSix]

Never built a turbo header, so you may be right about the Schedule 40. I think this is an area where my welding skills fail me.

[addo]

I'm hoping this thread will "grow" with some photos in progress of welding pipe to flange.

As someone with negligible welding skills, the more I understand what someone is supposed to be doing for me - the better!

[XFlow_Fairlane]

like I said before I would be down for a couple sets (4-6 prob) 3/8 is fine even for a turbo.

['68falconohio]

Didn't get the first one cut due to 80hrs of work. Will let all know when there's a good flange made.

[Invectivus]

I'm interested, idea of what the cost would end up being?

['68falconohio]

My contact will be at Lake Cumberland on vacation next week and I didn't get a chance to talk to him this week(work in the way). Sometime the following week(Aug 2nd) I should get a day off of work.

The plan is to burn a test plate in some 16 gauge and check fitment on my head, tweak the .dxf, then get the real thickness cut. Once the .dxf is verified it should move quickly.

I don't want to put my foot in my mouth on the price, so I won't throw a dollar amount out yet. Will let all know when I get a fixed price from my cutter. Sorry for delay.