Sport Scout header

[exeric]

Post hurricane, tons of clean-up and repair. Back to motorcycles.

I've been working on the exhaust system for this Scout and I'm experiencing a lot of difficulty installing the headers. Unlike any motorcycle I have built, the SS headers are welded into an assembly which must fit on angled cylinder spigots. Every twin I've worked on had a separate front and rear header pipe that joined in an assembly that allowed the requisite tweaking to get everything to fit. A welded 'twin' header would work fine if it was fittied up to parallel spigots. Obviously not the case with the SS header. As you can see; the rear pipe is off by 3/8"

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This is my first, and last Sport Scout project so I'm hoping to get the advice from an experienced SS builder. . . How do you install SS headers. Thanks for any advice, or suggestions.

[T. Cotten]

Me not experienced, Eric,...

But I'd grab a ratchet tie-down strap.

....Cotten

[jim d]

I drilled holes in two pieces of short 2x4 wood the same size as the p[pe. I then screwed eye hooks into each one. Attach a turnbuckle between them to pull it together. Countersink the other side of the block and point them toward each other.. Put the turnbuckle eyes in the countersink to jack the pipes apart.

[pisten-bully]

Eric! Good to hear we didn't lose you (kinda worried)! '46 Chief has a one piece exhaust, front to back, and even though I assembled it in place, fitting easily then welding it up, every time I take it off a similar misfit to yours occurs. So, I'll partially insert the front pipe into the cylinder, then finesse the rear pipe into its cylinder by manually squeezing it while rotating the rear of the pipe upwards. Once I get both pipes partially inserted in their cylinders then I take a rubber mallet and hit the pipe on the bottom upwards and they'll fully seat after three or four firm, but not heavy handed, whacks with the rubber mallet. Is it 3/8" off? Not sure ...but it looks like it'll never go in until it does! Ratchet strap....sounds like a good idea!

Welcome back!

[bernhardt]

Eric, Glad to hear you didn't fly away with the palm trees!

If it were me, I would heat the rear header with a rosebud torch, and bend it. I am not sure you could pie cut and weld, because front pipe might get in the way when you want to grind and finish out the weld. You want to get those headers as close to sliding into the spigots as possible. If you try to force it together without permanently changing the bends of the pipes, it will be a nightmare each time you have to remove and reinstall the exhaust. It seems I always have to remove and reinstall the exhaust a few times during the build, and also when sorting the bike out for the road. It's best to get the fit right at this stage, before plating or painting.

[kitabel]

Perhaps it's my vision, but the CL of the rear port is not parallel to the CL of the rear pipe.
Moving it over doesn't fix that.

[T. Cotten]

Perhaps it's my vision, but the CL of the rear port is not parallel to the CL of the rear pipe.
Moving it over doesn't fix that.

Yes, Kitabel!

Eric said they were 'angled' in his first post.

I prefer to bend things cold; Perhaps wraps of tape before applying the ratchet-strap would give grip as well as protection to the chrome.

Steel must be bent beyond perfect so it can spring back to perfect. If it can be installed more easily, with reduced stress upon the cylinderhead spigots, I'd call it perfect.

....Cotten

[kitabel]

My point was that bending it with a strap probably distorts the entire length.
It needs the last inch or two.

[FLFD7]

Eric,

Looks to me like those repop headers you got there were made wrong. I’m fortunate to have some NOS headers and they are so much closer

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They still need some tweaking, but nowhere’s near what you’re looking at.

I used repop headers on my ‘39 and same as you mounting them was a challenge. I had already had them chromed, so I didn’t want to resort to and cutting or rewelding. If I remember right I did use some take up straps to get them to fit.

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On my ‘42 I avoided the problem and had separate pipes made…

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If you are going to rework you headers and need a NOS set for a template let me know I have a second that I can lend you.

[tomfiii]

Even a NOS header pipe can be a wrestling match.

[PaulCDF]

On my Chief I needed to use: block of wood, scissors jack and rubber mallet (wish I had thought of the rachet strap or turnbuckle ideas).

[RichO]

Eric, If it were my problem to solve I would install a small furniture type clamp (two ends) into the pipe ends and as I pulled them closer together i would gently heat the fork where they join with a propane torch ( not as much heat as oxyacetylene) an from a distance so as not to change the color but to relieve the stress. That 3/8's at the top is only an 1/8 or so at the bottom. The angle will be right from what I can determine.A measurement between the heads will tell you where you need to be and the heat will reduce the spring back. Easy with the heat as most chrome pipes today have copper to buff out the imperfections before the nickle hence the the severe discoloration. They almost look stainless from the photos. Good luck.

[T. Cotten]

Eric, If it were my problem to solve I would install a small furniture type clamp (two ends) into the pipe ends and as I pulled them closer together i would gently heat the fork where they join with a propane torch ( not as much heat as oxyacetylene) an from a distance so as not to change the color but to relieve the stress. That 3/8's at the top is only an 1/8 or so at the bottom. The angle will be right from what I can determine.A measurement between the heads will tell you where you need to be and the heat will reduce the spring back. Easy with the heat as most chrome pipes today have copper to buff out the imperfections before the nickle hence the the severe discoloration. They almost look stainless from the photos. Good luck.

You people are starting to make me appreciate harlys.

.....Cotten

[jim d]

I used the blocks of wood with the drilled holes to size to prevent the top of the header from being deformed. I used them on a Chief stainless exhaust header with the same problem. I bent the header cold. I started there and then worked toward the rear. Issues from the front to the end of the tailpipe.

[exeric]

First of all, thanks to everyone who took the time to make suggestions. I've never had to deal with a header like this, so I wondered if I was missing something obvious. Glad (sad) to know this is a problem common to certain Indians and how others deal with it.

Tom's ratchet strap suggestion worked very well for getting the pipes on, and getting them off. When the pipes are on, and fully seated, you can feel that there is slight spring tension between the pipes, but not a concerning amount of stress, so, I think the ratchet strap application is the way to go.

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On the down side; the exit part of the headers don't clear the starter gear segment. I heated the pipe and was able to bend it away from the gear, but not enough. Too 'P.O'd to continue messing with it today, but feeling positive and expect a good results tomorrow.

exhead4b.jpg

I can't thank my fellow AMCA members enough for taking the time to help me with this. I still love Indians, but like Tom Cotten implied, they make you appreciate Harley-Davidsons