The Silver Buick's 1969 Firebird OHC six project.

[DanStokes]

I weld my stuff with the MIG then overweld with oxy-acetylene to melt the holes together. I've had pretty good luck with this. If something is super-critical, like say an oil pan, I'll tack it with the MIG and take it to Wilmington Sheet Metal where a real welder can TIG it all together. Cheatin', but it works.

I think my 6 cylinder headers have 2" collectors, maybe 2 1/2. So yeah, kinda big for what you want.

Dan

[squirrel]

one trick is to start the arc a little ways away from where you want to start the bead, then move towards where you want to start the bead, then start welding. This might give it a chance to get hot enough to penetrate well, and not leak.

[TheSilverBuick]

3-1 collectors are around $70 each and would still need to be modified down to the 1.75" outlet, and they are quite long as they are designed for full length headers and naturally aspirated.

I know what you mean about MIG'ing and leaks I have a fairly low success rate too. I did as much practice as I could with the cut scraps and played with the welder settings until it appeared to weld the best. Then I tacked welded the pipe at 120º intervals and tried to run each bead a 1/2 to 1 inch at a time always starting on a weld to minimize the chance of a leak. I also too waaaay more care on cleaning the metal where I was welding than I ever had before to also improve my chances of a good non-leaky weld.

[squirrel]

The problem I have with the MIG is avoiding leaks.

[Deaf Bob]

I would assume (asume?) there are 3 pipe collectors.. Think V-6...
Pentrention.. Without blowing holes! The kid can weld longer beads around the doors than I can.. Same settings! He is just better at it than I..
In some ways, easier with a torch, in other ways, easier with MIG...

[squirrel]

Can you buy a collector for 3 tubes? you can get them for 4 tube, it's pretty easy to do the collector with them. Just have to make a piece to fill in the center, then on the outside you weld the tubes together, up a ways to form a shallow valley. You could probably form your own collector, dimple it in three places to meet the welded in valley between each pair of tubes.

hard to explain, pics would help, I guess.

I envy you not doing this with a MIG

[TheSilverBuick]

First go at building a set of headers is moving along. Building the collector ended up more complicated than I had hoped, so hopefully it doesn't leak... I have a game plan of what I'm going to do differently, and better, making the next one. Basically for the next one I'm going to install a ring around the three pipes, seal it up on the three pipes and then weld the reducer to the ring. I may cut this collector off just before it reduces in diameter and re-weld some parts just to be sure it doesn't leak. Live and learn! The next three should go much easier as I'm pretty sure I've figured out what settings to use on the welder when simply welding versus filling gaps. Fun fun.

[Deaf Bob]

Sounds like it, but you better ask her.

Afraid of the answer, so I'll stay mum..

[hauen]

Sounds like it, but you better ask her.

[Deaf Bob]

I guess I'm old fashioned.. Marry for life.. She was a keeper when I asked her to marry me! Still is. 42 years in less than a month.. Is that a keeper?

[squirrel]

It's too late to figure that out, he already married her

Yes, she is great!

[hauen]

She's a keeper.

[TheSilverBuick]

I did some practice MIG'ing yesterday on all the scrap pieces. Got the welder settings to about where I think they should be to do the final welding.

The Mrs. also agreed that if I have the turbo on the Firebird by the time Drag Week 2017's registration opens, I can register Motivation!

[DanStokes]

Andy - Thanks for the Muggyweld info. Looks like just what I'll need when I make mods to the intake side for a bigger turbo sometime in the future.

Randal - The trick to welding thin stuff like exhaust tubing is to NOT expect to run long continuous beads like you would do on heavier stock. A short dot here and there (move them around to minimize warpage) until all the dots connect together. This is from a guy with MANY years of melting body metal together. There's a tendency to think "I could polish this off quicker if I ran this bead a little longer" and you'll blow thru and/or warp the whole deal. A bit less heat and smaller wire all help but still, do little dots.

For SS I have my little MIG set up with SS wire and a pure Argon cylinder. IF I get the base metals really clean it works great. I forget what diameter wire I'm using but probably 0.023".

Our local community college does NOT offer a class that includes MIGging aluminum, darn it. I have a spool gun that came with my Eastwood welder and the solution may be to just start melting aluminum wire 'till I get the hang of it but it would be nice to start with some instruction. I've bugged our local welding shop to do some weekend seminars but so far no luck.

Dan

[TheSilverBuick]

I'm fully committed, but this guy on the Pontiac OHC forum has hung a pair of Volvo turbo's off the side of the engine. He is still building the truck it's in, but did a short test drive around the block. He has some small things to still sort out.