Vintage Motorcycle Eccentrics

Hi Guys
The idea of the portable dyno came from a friend, John Horton who I met at the bonneville salt flats during Speed Week. He new of a fellow racer, a professional kart racer that designed and built a hydraulic dyno. The dyno was small, portable and used in the pits to fine tune his karts often between races and he was 'very successful', the idea sounded good to me.
The primary parts; used hydraulic pump and drive system, needle and relief valves, hydraulic tank, a cooler and pressure gauge(s).
Although the kart guy used a chain drive direct from the crankshaft of his test motors to connect to the pump it was suggested that I use a separate drive roller (thanks for the idea John Hanson) and this idea would allow quick set-up and also allow my team mate to run his Honda on the dyno too, a win-win situation
Because of the high temps on the salt and a small capacity reservoir I decided to add a heat exchanger to keep the hyd. fluid temps from getting out of hand. Swing-out stabilizers were also incorporated due to the narrow frame width (necessary to slide in the side door of my travel trailer) and to prevent a 'Tommy Tip-over' while running a scooter which would be very embarrissing. The drive wheel is a new Goodyear 5.00-5" aircraft tire which I feel should be good for at least 120mph before funny things start to happen!?
Anyhow, this is what happens when guys get together in the pits and/or shops and start thinking and discussing ideas. Since I started this build I have found similar commercial hydraulic dynos used in the outboard motor shops that connect a basic pump (w/pressure gauge) directly to the outdrive shaft (in place of the prop) and use a conversion table pressure vs. H.P.
I still need to diassemble,finish weld and paint (to match my bike) then TEST this thing ..... and make changes if necessary!

George McMurray, Tri-Mac-Speedsters, LSR race team

Any pics?

For those that haven't seen it, the Sequim Gazette did a story on George a couple of years ago.

http://www.sequimgazette.com/sports/art ... for_design

Sorry Guys ! I guess I should have mentioned that this dyno build discussion is about the same one that John Hanson had posted a photo of a day earlier, titled George's new Dyno.
George

Very cool, I have some hydraulic stuff left from my mill projects, hit me up if you need something- Doug

Thanks for the offer Doug. I've managed to scrounge up most of the parts, including the hydraulic pump which I've been toting around for years as a possible log splitter component that never happened. The only thing left on my 'need' list is a few feet of medium pressure hydraulic hose (-6 & -8 size) compatible with field reusable ends (which I have), a few fittings and hydraulic fluid. I did a test fit of the motorcycle on it tonite making sure I have adequate tie-down points before finish weld and paint. So far ,so good!

Mornin' people-

THANKS Jay for posting the link about George.

Great to see pics of your bike, George (as well as shop & dyno). Sheesh, between you, John H and maybe others, don't think there is much you guys couldn't figure out and put together! Good one.

Don't suppose that dyno would hold a Triumph? On second thought I don't wanna know---

Maybe see you guys tonight?

Tom

Kicked butt in the shop over the weekend and managed to diassemble, finish weld and spray some matching blue paint (same as my yamaha LSR). I use a 'Poly II' paint from Rodda Paints in Sequim and I'm very happy with the results. I'm no painter and not really crazy about paint prep and 'overspray' but..... it's a very durable urethane and looks like powder-coat when it sets-up. The only real drawback is it's available in 1 gallon kits only and it's a little spendy although not as bad as automotive stuff. I need something that holds up to the salt envirnonment and IT DOES!
Gordon had read an earlier post that I was needing some hose for the project and happened to have some Aeroquip -8 hydraulic hose laying around his shop and donated it "For the cause". Thanks Gordon, I'll get even with you!
If all goes well I'll get the dyno reassembled this week and try out this thing next weekend, cross your fingers. I'll get some pictures posted when it's assembled. Guess I'll have to have John H tutor me on picture posting!
George

Hello, from the racer's den in Blyn

News On The Portable Dyno:
Mounted my little Kawasaki KE100 as a test mule to the dyno and completed several pulls. I've found a couple of shortfalls on the design but fixable. The first is the increase in torque at the point of measurement, at the pump shaft which pegged my gauge at 15psi (lbs-ft). I've got the pump turning at a 2:1 reduction from the wheel driven shaft and this doubles the torque at the pump (without considering the other ratio changes ahead of it ie.,primary drive reduction). Anyhow, I've replaced the torque gauge with a 100psi unit and the little kawi achieves close to 30 lb-ft, indicated!
Now comes the other problem (shortfall), when I start applying some serious load on the bike (1,800-1,900 psi) I can hear (and feel) and audible 'thunking' sound. It appears I've also over estimated to load carrying capacity of the 1" wide cog-belt and no matter how tight it's tensioned it jumps teeth at high loads.... hmmmm!
I've worked out a solution to the problem and have decided to go with a roller chain drive and ditch the belt. Parts are ordered. This "will" stop the slippage/tooth jumping.
Last night, John and I threw around ideas on mounting/aiming the squirrel-cage cooling fan for the different scooters that I will run on the dyno and I shall try to fab something today
With John assisting in the 'Think Tank' for fixes, things are moving right along and so far so good on all the mods. I'll ask John if he can post a picture of the kawi on the dyno as I tried but failed (even with the wifes help) and continue to be completely stumped on how to post pics with my PC! Seems I can machine it but cannot post it, HaHa.
See ya guys later!
George

Thanks for the update!

This is something I should look look into building.