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Can anyone recommend a good supplier for exhaust pipe (plain steel or stainless)? I suspect most of the places I'm looking at are really overpriced - does plain steel pipe and generic mandrel bend pipe really cost an arm and a leg?
 

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Try this place:
http://store.racing-solutions.org/mildsteel1010.html

Look also in your phone book if there is a tubing supply or sheetmetal fab shop close to you and ask them. There's a local place (Anahiem, CA) that I get u-bends for like $6-7 each. Straight mild steel tubing should be able to be bought at a metal supply house, you need probably 1 1/2" or 1 3/4" in 18 gauge. Can do 16 gauge in the straights but it gets heavy.
 

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I bought several stainless "J" bends off ebay really cheap

haven't priced mild steel but I am sure it's much cheaper

one or two will make a set of pipes for a two cylinder easy

just add straight section
 

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Discussion Starter #5
Thanks for the link!

On exhaust headers, I note that there's either a squared shoulder or a rolled lip (flange?) on the the part that mates with the cylinder head. For those of you that fab exhausts, what do you use to make this lip, just a ring cut out of sheet metal? is there a tool that will roll this lip?
 

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the tool you are thinking of is called a flanger. I have one for small copper plumbing tube but for the big stuff you may have to go industrial. Or you just cut your old ones off and weld it to the new pipe.
 

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I haven't looked to far into it yet, but getting a thick steel washer that has the right OD and ID and welding it to the end of the new head pipe should work too. Might have to get the lathe involved for the right OD, we'll see. Until then, like Geeto said, I too cut the ends off stock pipes and build from there.
 

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quote:Originally posted by CBGP

I haven't looked to far into it yet, but getting a thick steel washer that has the right OD and ID and welding it to the end of the new head pipe should work too.
here is why it won't work on some bikes. both sides of the flange are used. The side that faces the head seals against the exhaust gasket and takes the heat coming from the motor. The side that faces away from the motor sits against two shell clamps (kinda like bearings) that are held in place with bolt on clamp. If there is a bead weld sitting on the junction of that flange the shell clamps will not be able to seat properly and put adiquate force on holding the pipe in place. I suppose you could grind them but keep in mind that flange is the harshest part of the exhaust rapidly heating and cooling. Typically when an exhaust pipe cracks it cracks at that flange.

as long as you are making pipes, you can re-engineer the mount to work better. what I would do is make a bolt on collar that had a smaller thicker pipe halfway inside that fits into the head and seals it. Then the rest of the exhaust would slip into the collar an be held in by springs. Look at how any kawasaki h2 aftermarket chambers mount to see what I mean.
 

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Discussion Starter #9
You mean like the cb750K exhaust spigots?

EDIT:

So basically, you could take a piece of relatively thick-walled pipe (something heavy enough to seal on the exhaust gasket), weld a flange halfway up on it, and bolt that on, then clamp or fit (via springs, maybe) new pipes to the other end....that sound about right?
 

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I do the washer thing, turn the ID and OD on my lathe. TIG weld it on, no bead, never had one break yet. I use shims about 1/8" thick. Can get them very close to the size I need so not much lathe work. I use this setup with the OEM half shells. I TIG weld it around the ID on the port side only, comes out flat as can be.
JohnnyB
 

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Discussion Starter #13
Thanks for the answers!

I had to hit the WayBack machine to see Headers by Ed - his site has been down for a while, apparently he is still making headers though.
 

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quote:Originally posted by jbranson

I do the washer thing, turn the ID and OD on my lathe. TIG weld it on, no bead, never had one break yet. I use shims about 1/8" thick. Can get them very close to the size I need so not much lathe work. I use this setup with the OEM half shells. I TIG weld it around the ID on the port side only, comes out flat as can be.
JohnnyB
BINGO!
 

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I simply machine that flange and it's no big deal at all

typically doesn't hurt one bit for it to thicker, more substantial, and often the physical constraints and pipe/port sizes lend themselves to anti-reversion measures at that point

there is nothing special about that metal on the end of the pipe and my opinion is the section of pipe directly in front of the whole laminar flowing slug gets hit the hardest with heat

it has nothing to sink heat away from it

if you are good with a tig welder, an autogenous bead will leave everything never caring that it happened with the end results being that weld bead being the last place it will fatigue or fail unless you did something half-azz mounting the other ends of the pipes

when building exhaust pipes

start at the exhaust port and work your way to the loud end

so your flanged spigots would be the place to begin
 

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quote:Originally posted by Geeto67

if JB says it will work then it will work.
The TIG welding is the key...like you say, bead would get in the way with a MIG. I've got pipes I've done up this way down to .049" wall that have held up nice so far.
Here are some pics of some systems I've built, one using the above washer method, one finished system with a spigot and spring mount (spigots no shown).
http://www.jrbranson.com/HondaRacer/CB175/building_an_exhaust_system.htm

My preference for spigot or flange setup depends on two things...how often you might need to remove the head pipes...and if there are any heat issues in the exhaust port area of the head. 175's have the latter condition, so it's a welded flange, copper oring, and a finned alloy collar.
JohnnyB
 

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nice one! Did you roll the cone on a slip roller or over a pipe?
 

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I use a slip roll, then finish by hand and with clamps. Not bad after you do a few dozen of them. Would help if I had a nice old school Pexto roller.
JohnnyB
 
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