The only concern I would have is the clutch being strong enough to handle the weight.
transman
Oh definitely…the project is probably the most fun part of this whole thing. Regarding the transmission…The Justy trans goes out for scrap on day one…not needed here at all and is verified as being POOP. As for handling and such…lol…lets just say I will be happy to be going down the rd in a straight line under Goldwing power…LOL. But I have aluminum wheels with wider and lower profile tires for it already…that should help in the turns
The clutch SHOULD be fine…I’ve worried about this as well.
The weight of the Justy IS 1896 Lbs I would say the engine AND trans together weigh…400lbs? Maybe more? less?
So approx 1500lbs vehicle with 120Hp…Its getting faster and faster from where I sit…
This is a great project. Fitting all of the pieces together will be a great accomplishment. I?m going to offer some cautionary advice. In this application you will be pushing the design limits of the GW engine and transmission in both sustained and impact loads. Rolling resistance and aerodynamic drag will be substantially higher. There isn?t much you can do about the drag, but try to stick with narrow tires and a hard compound. Consider using lighter lubricant in the differential and the front wheel bearings. Don?t underestimate the amount of energy required to spin up the driveshaft, differential, two axles and the two rear wheels. When you chop the throttle most of this energy will dissipate back through the drive train and into the frame through the motor mounts. Keep the spinning parts as light as possible and build a fair amount of flex into the motor mounts. In a motorcycle, the suspension cushions a lot of the drive torque. Not so in a car. Motorcycles have inherent torque limiters that protect the drive train from impact. Wheelies (not possible in the Justy) and tire spin both reduce impact to the drive train on hard acceleration. The Justy will have a lot more traction and inertia. The GW transmission won?t take kindly to a lot of holeshots. Work out the final drive ratio taking into account the rolling diameter of the wheels. You may decide gearing up or down is needed. The GW uses the starter motor, plus driver assist, for reverse. Don?t plan on backing up any hills.
Hey…MUCH obliged…Its nice to see an answer or comment that obviously has a lot of thought behind it. I too have thought about the loads on the engine and trans. I had planned on feeling it out to see if I would have to go up or down in gearing. It was unclear to me just exactly how the GW reverese worked…and what you told me does ring true for sure. I knew that there was an electric switch on the bars that engaged reverse…what I didnt know or remember was that the GW starter motor took it from there…I had heard that a few GW used the starter for reverse…I thought or wished that the electric switch engaged the reverse gear but then hoped that the GW engine itself took reverse from there…seems I was wrong and now that I think about it…unless the reverse gear was super low low low…how could one handle a motorcycle with reverse engaged and the gas engine driving it without going wildly out of control? LOL…funny mental image… I appreciate your comments however and will take ALL into consideration for certain. I have a lot of people on here ready to see some progress…myself included. This has been in the planing stages a long time. It will be fun to finally begin working on it.
I always had in mind that we would be gentle on the throttle in all ways…just gradual acceleration until all the parts have been felt out.
Sounds like you’ll do fine. Just-FYI A factory modified Justy took a land speed record at Bonneville. 117mph. Check http://www.driveperformance.subaru.com/version4_1/atticpart2.asp
Best of luck. Look forward to following your progress.
This thread appeared at the top because of a new post that was deleted however I was unable to find the project videos on Y tube, has the project started yet?
If you used the rear axle assembly out of an appropriately wider car, you would have to only shorten one side of the axle housing and shaft to have a perfectly offset differential.
Has anybody else noticed that this is a 6 year old thread?
I sure didn’t.
Seems like plenty of time to get this project started.
Maybe HB is busy with his project. At least there is no danger of a future classic car being destroyed by extreme modifications.
You have to consider the fact that most all motorcycle transmissions have a primary reduction ratio ahead of the transmission. The GL-1800 has a 2.75:1 rear end ratio and with a 180/60-16 rear tire, the engine is spinning around 3000 rpm @ 70 mph even though the output to the drive shaft is only spinning 2640 rpm.
If the rear axle on your Justy has a 3.7 or 4.1 rear axle ratio, you are going to have a real buzz bomb when going down the highway, as in permanently in a passing gear.
Where did you come up with that?
Oops, didn’t realize that this is 6 years old.
Had a bud put a 350 in an mgb, had to beef up the front suspension a bit, might consider offsetting the engine to match the driveshaft, but I do not know enough about the particulars
V8 conversions for the MGB are pretty well known, more often with the Ford 302.