I cut the front header and ground it to where about 20% of the ends make contact. Stett's going to TiG tack it tomorrow morning. It'll take two trips to his shop, but I think it's going to all fit together ok.
You can see how much lower the spigot is than the hub, which begs the question - Could I make the spigot meet up with the hub by simply cutting 1/4" off the end? I would say no, because, as you can see the hub of the header is installed on the head's exhaust spigot. The radius of the curve needs to be changed. The only way to change that, imo, is to remove a 1/8" section in the middle of a bend. The pipe has a cut 2/3 of the way through it.
The two halves after being cut.
I picked the half that was the most un-even across the top and flat-ground that raw end with a 7" diameter grind wheel to make the end more even.
The header doesn't sit squarely on the hub. So, when you see the pic of the ends matched below, I can still remove a little more material from one end of the header and it will move forward and change the position of the header hub to be more aligned on the head's exhaust spigot.
Hand-filing some more off the leading edge of one of the pipe ends will allow the header to move forward a little but will help align the header hub with the head spigot.
I used a Sharpie pen and pocket ruler to make three series of marks. Stett will match the marks and tack it.
Stett welded it in one pass. I made the three alignment lines at different places across the two halves. He tacked the pipe, and asked me approve the alignment relationship of my marks, then suggested I take it back to my shop and check the fit. His tacks we so right-on
to my marks, that I asked him to finished the weld.
Even a gnat-hair
of wrong angle would have affected the final fit.
The header fits, but lifts the head 1/32 of an inch. I'm going to flat-grind the top of the header hub slightly and it will all fit together with at least 0.030" of air space between the top of the flat-pipe and the crankcase and at least 0.030" of air space between the right down-tube and front header.
I wouldn't suggest anyone trying what we did, by not having the motorcycle at the same site as the TiG welder and winging it
. It could have gone horribly wrong. Easier to pull tacks apart than a whole seam.1-11-08
It all fits sweet
I can easily remove the four pipe sections. There is no bind between the pipes. Nothing is forced. It's like working on a two-wheeled art project now. Too bad the front header doesn't fit right out of the box. You might be able to just shorten the spigot end of the front header without cutting it in half, but I didn't take that route. It seemed to me that the arc of the header was not enough. I'll post a pic of our modified header over a swing-arm front header and we'll compare the arc bend
and see if ours is now radically different from an off-the-shelf '48-65 V-Twin header (which is 1" shorter by design, but the arc was originally the same as the '48-57).
Here's the tools that made cutting, grinding and filing possible :
(Left) A Sanvik® saw works better (blade is supported at the pins) than a standard hacksaw. A Remington-Dupont, "Grit Edge" tungsten carbide blade cuts straight
and leaves a 0.060" kerf (cut), which is wide enough for the relief slots in the hub. We cut four slots instead of two, so the hub will close on the spigot. The blade cuts fast, so mark the slot lines for 1/4" max. depth and cut with a blade 3/16 deep and finish the last 1/16" with a round file.
The 7" wheel removes a lot of material evenly. The 4" wheel I used for contouring the top of the hub edge, where necessary.
The file is a 2nd cut - Used it to draw file the top of the hub after the 7" wheel.
The fine tooth pin-file was used to remove the sharp edge off the hub's I.D and O.D.
(Right) The Foredom Grinder has been another tool that has helped with the build in several areas. It has 1/8 and 1/4" chucks. The stone wheel was used to remove weld from the I.D. of the hubs where the slots were filled. The Foredom will turn the sustained rpms you need to knock down TiG beads.
Welds were done by http://stettsironhorseranch.com/
where they pay attention to detail.
To keep the muffler assembly aligned at the motor area
, I've temporarily installed this spacer between the clamp and frame.
This front muffler clamp's position also pulls the entire rear assembly into alignment. It's this clamp's eventual position that will remove the need for the spacer I have at the rear muffler clamp now.
The frame tab and pipe tab don't match up. The flat-pipe's tab will need to be removed and re-welded to whatever position your assembly requires. In my case, I'll need to put the clamp next to the hub and maybe hog the hole some to the left. Between the two tabs is a place that is shim-able if necessary. This frame and flat-pipe tab clamp controls the in and out of everything that might create metal contact (brake arm) or header hub-to-spigot stress. Imo, with everything dialed in, you should still be able
to move the headers slightly before you tighten the exhaust clamps to the head.
There is plenty of clearance between the front header and the cradle and between the top of the flat pipe and the crankcase. And the side seam of the flat pipe gets close to the motor groove, without binding into the crankcase. (Every
crankcase needs the groove or one cut into it.
There is at least 1/64"
between the top of the header hub
and the heads. This is necessary to allow the pipes to turn slightly, and the entire assembly
to settle in to position.
This is the position of the trans. at slightly over mid-way back.
This is moved all the way forward.