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Flattrack racer build
- Thread starter Champion750
- Start date
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- Tags
- tracker
Champion750
XS650 Addict
All done!!
It doesn't do the job with finesse but it get's it done and after testing it a couple of times I'm happy. I know I'd never be able to get that engine in the frame without it. The real test will be when the engine is in race trim. In these pics only one tranny shaft is in place. The rest of the engine is gutted. I'm guessing it weighs 50 lbs in this state.
If anyone wants to see it work I'll try to post a video soon. Thanks for any interest, it was a really fun project.
It doesn't do the job with finesse but it get's it done and after testing it a couple of times I'm happy. I know I'd never be able to get that engine in the frame without it. The real test will be when the engine is in race trim. In these pics only one tranny shaft is in place. The rest of the engine is gutted. I'm guessing it weighs 50 lbs in this state.
If anyone wants to see it work I'll try to post a video soon. Thanks for any interest, it was a really fun project.
Attachments
Champion750
XS650 Addict
Got some work done on the 750 exhaust today. Pics show what I'm starting with thanks to SPD exhaust components in Rancho Cordova CA. I'm gonna try my hand at stainless this time. I'm also gonna try going without mufflers. I've seen some guys racing with straight pipes and its surprising how 'not loud' they are. I'm also trying to get as close to the specs in Craig Weeks manual as I can.
So far I've started the collars and then on to the head pipes.
So far I've started the collars and then on to the head pipes.
Attachments
Champion750
XS650 Addict
More work on the exhaust. Collars and sleeves are made so now is the tedious process of cutting and fitting up the pipes. I'm trying to make the head pipes 31 inches long and in the last pic that shows what I've made so far, it is only two inches short of that. I'm using the Hoos Racing Shell style pipes as a visual reference and as it turns out my pipes will be quite a bit shorter that theirs.
Also its like 100 degrees outside where I live so welding in this heat kinda sucks
Also its like 100 degrees outside where I live so welding in this heat kinda sucks
Attachments
Street Tracker
Dirt Track Mentality
A good length for optimum performance from what the gurus say is 39", what made you decide on this length if I may?
Champion750
XS650 Addict
Craig Weeks' Engine Modification Guide.
The only race pipes he mentioned that came close to 39 inches were Harry Lillie's TT pipes. They were 42" pipes with 1 5/8" tubing. All other systems from Shell, Axtell, Yamaha race department in the '70's, Lillie, Atkins, etc., all recommend pipes in the 28" to 32" range for half mile and mile tracks. Maybe more info has been discovered about this but I thought I would start here and see how the engine performs on the dyno and the track.
This is my first XS650 build so I try to keep an open mind about things. When I finally get this thing on the dyno I will post my results. We will see....
The only race pipes he mentioned that came close to 39 inches were Harry Lillie's TT pipes. They were 42" pipes with 1 5/8" tubing. All other systems from Shell, Axtell, Yamaha race department in the '70's, Lillie, Atkins, etc., all recommend pipes in the 28" to 32" range for half mile and mile tracks. Maybe more info has been discovered about this but I thought I would start here and see how the engine performs on the dyno and the track.
This is my first XS650 build so I try to keep an open mind about things. When I finally get this thing on the dyno I will post my results. We will see....
racerdave
^ Gone not forgotten ^
I wonder if these are the Lillie pipes? King Kenny at Peoria TT
Champion750
XS650 Addict
There's a break in the racing season so I was able to get going on the 750 project again. Pics show progress on exhaust system. The pipes didn't turn out perfect but they'll be fine. Also made some little do-dads to tack weld on the back side of the number plate mounts so I only have to use one wrench to mount/remove the number plates. This frame really should have come with these....
Making lots of progress lately so I'll have more pics soon. Next is foot peg mounts and rear brake set up.
Making lots of progress lately so I'll have more pics soon. Next is foot peg mounts and rear brake set up.
Attachments
hoffman900
XS650 Addict
Keep in mind these are probably overall length numbers. Throw a a muffler on it and the number is now meaningless for the most part. You need to introduce a step (change in area) at this point and carry out the total length, including the muffler to your 2nd harmonic point.
Exhaust length is really a function of horsepower peak rpm and intended power band. It's also a function of pipe diameter as a larger pipe needs to be longer than a high velocity smaller pipe. The more overlap you have, the more critical and sensitive the engine is.
Anyway, to the op, looking good!
racerdave
^ Gone not forgotten ^
Champ, any reason for the Maxis/golden combo?
Champion750
XS650 Addict
Racerdave,
First off I've never raced an XS650 based machine so its a guess. Most of my races will be on hard pack/clay blue groove type tracks and this combo has worked well on my other vintage bikes. The choice for the Golden has a lot to do with the price. The Dunlop/Goodyear works good but they are $50 to $60 more than the Golden. Also I have other spare tires on hand so this set up may change. We'll see.....
Hope that helps
First off I've never raced an XS650 based machine so its a guess. Most of my races will be on hard pack/clay blue groove type tracks and this combo has worked well on my other vintage bikes. The choice for the Golden has a lot to do with the price. The Dunlop/Goodyear works good but they are $50 to $60 more than the Golden. Also I have other spare tires on hand so this set up may change. We'll see.....
Hope that helps
tonyc
XS650 Guru
Champ you do great work. What a great lift that you made. I am sure you could sell a few to the members.
Champion750
XS650 Addict
Thanks Tony. They wouldn't be cheap. It was a lot of work. Fun tho...
Slide
XS650 Enthusiast
When mounting the engine did you make sure the center line of the primary shaft lined up with the center line of the swingarm shaft?
....Mel #29....
Champion750
XS650 Addict
Not sure what you mean Slide. Do you mean lined up relative to the rear axle or crank center line? Do you mean parallel? You can draw a straight line through the primary shaft (output shaft) and the swingarm shaft no matter where they fall. I will be checking alignment of the primary and secondary sprockets if that's what you mean.
Sorry for my ignorance
Sorry for my ignorance
Champion750
XS650 Addict
More work on the right side foot peg/brake set up. Also added a secondary mount for the exhaust system. This is the last big fab set up for this bike. The left side foot peg set up will include a roller/tensioner for the chain but it will still be a lot simpler than what I'm doing here.
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Slide
XS650 Enthusiast
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Hey Champ, didn't mean to offend. Just inquiring whether your output shaft and swingarm bolt were parallel as this is the best set up. Also, if you can, mount the shocks with a 7 degree angle from the swingarm bolt with the rear wheel (if on) off the ground. This info comes from Dave Durell and Gerry Cheney. Hope the build goes as well as it has and have fun racing that bike. Attached are pics of my tracker and XT540 flattracker.
....Mel #29.....
[/URL][/IMG]
Not sure what you mean Slide. Do you mean lined up relative to the rear axle or crank center line? Do you mean parallel? You can draw a straight line through the primary shaft (output shaft) and the swingarm shaft no matter where they fall. I will be checking alignment of the primary and secondary sprockets if that's what you mean.
Sorry for my ignorance
Hey Champ, didn't mean to offend. Just inquiring whether your output shaft and swingarm bolt were parallel as this is the best set up. Also, if you can, mount the shocks with a 7 degree angle from the swingarm bolt with the rear wheel (if on) off the ground. This info comes from Dave Durell and Gerry Cheney. Hope the build goes as well as it has and have fun racing that bike. Attached are pics of my tracker and XT540 flattracker.
....Mel #29.....
[/URL][/IMG]
Attachments
bt24
XS650 Addict
Looking very nice!
Champion750
XS650 Addict
Hey Slide, nice bikes! Both look like fun fun fun. I've got a SR500 flattracker too...love it. Out of the three bikes I normally race I like that one the most.
Onward and upward...got more stuff done on the 750. Got the right side foot peg/brake bracket finished. Still need a brake line tho. Got the left side foot peg bracket finished too. I'll shorten up that left side peg up a bit so it doesn't drag so much. Also got the chain slider and roller/tensioner started. As you can see in the pic with the red arrow the chain comes very close to the roller bracket. I had to counter sink the bracket for flathead bolts and ran into some issues there. I'm worried that the chain is going to rub on that bracket. We'll see.
Onward and upward...got more stuff done on the 750. Got the right side foot peg/brake bracket finished. Still need a brake line tho. Got the left side foot peg bracket finished too. I'll shorten up that left side peg up a bit so it doesn't drag so much. Also got the chain slider and roller/tensioner started. As you can see in the pic with the red arrow the chain comes very close to the roller bracket. I had to counter sink the bracket for flathead bolts and ran into some issues there. I'm worried that the chain is going to rub on that bracket. We'll see.
