Fitting tubes to Header flanges.

From all my years of metalworking I have a few ideas how to do this, I'm just wondering if there is something simple or easy that I just have not thought of.

What I am referring to is forming the round exhaust tubing in my lakes headers kit fit the square holes in my Y Block header flanges.

Ideally I want a little of the tube through to the inside of the flange to allow welding and grinding as is typically done with no weld on the outside of the flanges.

What have you done or seen done ?

 

I just take a hammer and tap them out square ( or rectangle). I have thought of building and arbor ( mandrel?) to happer them on and if you have access to a good end mill it would not be hard to do but you would have to have a different size for every hedader flange.

 

I wondered about that myself. I thought a hardwood mandrel may last eight heated tube bend tries. On the Y block heads, be sure to open up the holes to the gasket size, and remove most of the hump. If interested, I have some pictures of porting those heads. Never been able to post them, PM me if you want to see them.

 

You can use a photo editing program and shrink them down if your pictures are too big.

Then you could post them.

My ECZ-G heads have had the mild porting done by Tim McMaster when he built my engine so they should be good to go that way

 

take a piece of square stock the size of the hole in the flange. then grind a round taper down to the size of the round tube and tap it into the pipe gradually squaring up the pipe. if that makes sense to you. hard to explain in words i guess.

 

I squished mine in a vice to one dimension, then a C-clamp and two blocks of wood the other direction while it's still in the vice.

I also like to weld the head side, then braze a fillet on the outside. It looks good and helps it not to crack.

 

Cayager, excellent method!
I'd make the form long enough to have a tail, so you could secure it in a vice and wiggle the tube back off it.

 

I think I'll try that. Good idea, thanks.

Tip of my anvil or some square stock to form the tubes.

 

I have used a tapered mandrel like cayager suggested, it was machined in lathe with a 4 jaw chuck to a slick finish, use some grease, it will be easier to get apart. The pics show the silicone bronze on the outside of the flange as Flt-Blk referred to, it works great and makes them last.

 

Nice looking work!

 

I just cut some .188 wall rectangular tubing into quarters tapered to fit the port size about 1" from the "small" end and weld the quarters back together. Start the end opening with the vise and clamp method, then use the swedge to finish it. If you have a bend very close to the head flange, you may need to make a very steep taper on the swedge. In that case i will throw a little heat to the header tube to ease it's pain.

Be sure your port alignment marks are spot on, it's a one shot deal if you're swedging into a bend!

 

A couple of ways...they wanted 75 bucks for just the flanges I bought a ratty set of headers for 50 bucks and cut the rusty junk off. The starter pieces are still factory welded. They do not go bad this close to the heads.

A ball peen hammer and a torch will get them to fit beautifully and then weld them up from the inside.

 

We use the method by Cayager, but in some cases the tubes requires a turn right at the flange, not letting you use a mandrel.
When this is the case we tack the tube at the four points that contact the flange, then form the corners with a piece of round stock and a hammer.
As stated, weld the inside,then use silicone bronze around the outside of the tubes. We have used this method with several sets of turbo headers with good results.
SPEEDY

 

At one of the header shops (Horsepower Engineering) I used to work at we had a multi size arbor plate that was welded to the top of a steel tubular post. This arbor plate had various square & round shapes protruding out from it so as to correctly form a given diameter of tubbing to what ever size and shape of flange ID. It worked great and used it for many years.

 

when i did mine i am a machinist i milled two jaws out of aluminum to the shape of my port , then i would put the tubing in my vise w the machined jaws bolted in and start turning it in , perfect form and slid right into flanges and tig welded them up

 

Lots of good ideas here. Thanks fellas I'll see which one works.

I think I like the look of the silicone bronze around the outside of the tubes.