Header mod - cut, bend, reweld?

[pago cruiser]

Trying to mod some Triumph mufflers to fit on the XS with stock headers, and I need to do a slight adjustment to the header discharge angle just aft of the frame mount because the muffler hits the shock bolt....

Basically, I'm going to cut the '77 header backside, just aft of the frame mount, clear through for about 1/2 the pipe width, tweak the remaining about 4" of pipe out until I have about a 1/8" void, then... carefully... weld the double wall void I created.

Should work, but I'm not sure of the double wall issue. The inner pipe is thicker than the outer, so they my expand at a different rate when hit with a MIG/TIG? The ebay set of headers I'm using are also pretty rusty inside for the area I'm working in.

I'm more of a tacker than a welder (in that my welding skills have greatly increased my grinding skills...), so my modus operandi is to fab the work, tack in place, then take to a really good welder for completion.

With all the different threads on here about exhaust, could not find one on bending the stock headers. Don't see a reason for this not to work?
TIA

 

[angus67]

With all the carbon and rust in the pipe, it will be very difficult for even a competent welder to make a strong weld. Also the chrome will give off a toxic gas.
Im not sure of what year but i believe the early pipes don't have that kickup. Perhaps a new set of repop pipes from mikes xs would be better. They are single walled

 

[pago cruiser]

Thanks for the reply. We have actually dealt with the chrome issue b4 by grinding off in the weld area. But the rust issue has always has always been a problem.
I actually need the kickup; but I also need it kicked "out".
I purchased a set of Mikes replacement headers, thinking this would make this easy. NOT. The bend is quite a bit different from stock, and it made the alignment of everything worse.
In doing a trial fit, it appears I may also need about a 2" length setback; maybe I can incorporate my kickout in a single wall spacer. Problem is, the 40mm stock headpipe diameter is a bugger to find something to clamp over it. I've spent about 2 hours this am grinding (with an industrial dremel and carbide bits) about 1mm out of the inside of a 1.5" OReillys adapter to slip over the headers. I'm still not there... If I can get this to slide over the header, then I can weld it on a bit wonky (not straight) and pick up the kickout this way.
Sigh. At least it still beats being at work...

 

[weekendrider]

I've use washers between the tab and the frame to kick them out 1/4 - 5/16 inch.

 

[pago cruiser]

HAH! Great minds think alike
Should have said that in my first post.
That was my starting point, using (2) 1/8" thick washers.

 

[angus67]

Do you still have the repops? id buy them.

 

[pago cruiser]

angus67 - you'll have first dibbs when I get that far. I usually do, but I move slowly... Been doing this long enough that I seem to go thru a couple iterations till its done...
Got it mostly mounted using a couple adapters, but it took all fricken day... and the adapters look like poo. I remember a thread where a guy used a 1.5" chromed lavatory drain as a cover - may have to look into that. And my hands are impaled with about a dozen teeny tiny metal splinters...still need to fab a rear bracket... then do the other side next weekend...
If you are in a hurry, I'd look elsewhere...
But it is progress. I like the look of the stock Triumph peashooters, and they are pretty quiet. I like quiet. Since they were designed for the Triumph 900 twin, I'm thinking/hoping jetting should remain unchanged as I still have the stock headpipes.

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