Sunday, June 15, 2008
Monday, June 9, 2008
Anyhoo, with a multi-cyclinder bike, there seems to be several ways to plumb out spent exhaust gasses -- a 4 banger might have a 4-2-2, a 4-2-1, and a 4-1; a triple might have a 3-1, or even a 3-collector-3 for style points (think new triumph speed triple); twins can be a few different configurations as well. My EX 500 was a 2-2, with a crossover under the engine; the Muzzy race pipe was a 2-1; stock Ducatis are primarily 2-2, with a bizarre, restrictive-looking X-piece underneath the rear of the engine. Ducati superbikes sacrificed some power for the sake of style and less drag with their then-radical underseat exhaust. Harleys (don't laugh) are one of the few large-displacement twins with separate headers per cylinder, with no crossover. They seem to make it work by focusing on keeping the header length the same, or as close to it as possible. Easy on a 60 degree cruiser with the turning radius of the Titanic; less so with a sportbike with a 90 degree L-twin. The route to the rear of the bike is far shorter with the rear cylinder.
My eyeball engineering has come up with this:
- now modified, the header diameter is the same for both cylinders
- the foward cylinder header is now 5.5" longer than the rear (before it was 9+" longer)
- guesstimation states that the two bends in the shorter rear header is equivalent to adding length the the rear header... theoretically bringing the total length of each closer to the same
Saturday, June 7, 2008
The lower exhaust canister mount is bolted to the spacer plate behind the rearset plate. The mounting holes are relieved so the heads of the bolts do not contact with the rearset plate.
I finished up the Suzuki 500 GP model awhile ago. I have been saving a "Fastdates 2001" calendar since December of that year. It was given to me by Scotty at Transcanada, and I kept it as it has this picture, as well as one of Garry McCoy from that year.
My plan was to always create something like this, with the model mounted to the action shot backdrop. I might use a sort of display box from a hobby store for the Red Bull YZR500... but I like this. Only 7 years in the making!
Sunday, June 1, 2008
Since I was going to make a set of shorties anyway, in the interim, I hacked about 5" off the end of each of the exhaust stacks. While they looked 100 times better, what resulted was a straight-through type set-up, so when I fired up the bike, it was obscenely loud. Good news is, the bike still runs after a year dormant. Bad news is, the exhausts still need more work. This will involved some perforated tubes and nutserts (on order), and another trip to Cycleboys to tig weld the assembly back together again. The resulting cans will also be much lighter, and should have a more "rorty" exhaust note.
Wilson came over yesterday, and we chatted and I was able to weld a tab back on his TZ250 expansion chamber. His indication is that Gimli as a track is on the mend -- the turn 8-9 combo is being modified properly, and might even end up as a safer turn. I can't forsee me making it to the track before September this year... the trip in July and the resulting financial crunch will put a damper on my trackday excursions. It would be a good opportunity to "test" the bike before putting it on the street. I should probably sit down and put together chapter 3 of the Ducati build chronicles for Desmotimes -- see www.Docc.ca for a great website, forum, and club. If you are reading this, you should join!
Switched around some banjo bolts yesterday as well, and now have all the hydraulics bled and sorted -- the clutch, front and rear brake systems are all operational and ready to go. Another 20 zip ties, and all of the electronics and wiring is out of the way, including the front wheel speed sensor for the speedo. Just the pipes and a place to put the plate, and it should be able to hit the road!