Centrifugal clutch on jackshafts?

[5-7HEAVEN]

Hi 5-7. This is off topic and I'll try to keep it short. I've been studying gear ratios, jack shafts, torque converter's etc. I've read a bunch of your posts. I think the germ of an idea is starting to emerge. This may be way cool, but I'm going to let it ferment a bit before sharing. Anyway, thanks for your knowledge.
Aw. To heck with it. I'll post it in general so people can tell me why it won't work.

Alaska, see you in "General Discussion".

 

[Egor]

The drive you are thinking about was used on the 1903 Indian. Works well and is a good idea. Have fun, Dave

 

[5-7HEAVEN]

Egor, i nixed the centrifugal clutch on the jackshaft because the happy time engines' gear reduction would not allow the clutch to activate(theoretically). besides, i don't think one clutch would be able to handle twin engines' torque.

my handlebars would be less busy if i could utilize the centrifugal clutch. right now i've got twin throttles, twin clutch levers and front brake lever on the bars. i could've relocated the clutchers onto the frame itself.

so my jackshaft will just accommodate three 10-tooth sprockets and homemade pullstart mechanism.

and maybe an alternator pulley.

 

[Egor]

You should not try and use so many control's. Go to Honda and get a throttle cable for any 60's twin, you will see how they split for two carb's. You can use the centrifugal clutch out on the counter shaft but it must be spinning at correct speed. Whizzer uses two clutches in there two speed clutch, you would have to see it apart to get the vision. I was going to try and build a twin engine I think it would be cool. I was looking to move the front engine close enough to engage the large gear to the crankshaft gear of the second engine. This way you would only need the clutch on the second engine, you could leave all the extra parts off the first. If you modified the cases on the two engines I think you could seal them up with silver sealer and you would not tell. The intake and exhaust would need extensive mods to stay out of the way and good motor mounts to keep the gears meshed. That could be a plate that would pick up all the cover screws and then place the covers over that with them trimmed down. OK all solved lets get two engines and have some fun. Lets call Duane and get two of his sale engine kits. Have fun, Dave
PS: Have you seen the twin engine Whizzer? I think he is going 90MPH now.

 

[5-7HEAVEN]

Egor, thanks for input.

i chose the simplest, cheapest route. aside from multiple controls, it is also the most accommodating. the engines are mounted side-by-side, never contacting each other. they will be bolted onto individual mounts, then onto a 1/8" metal plate. each engine can be separately adjusted for chain adjustment towards the jackshaft. the 1/8" plate also mounts the jackshaft; this plate is bolted onto a 3rd plate, which is welded to the bike's frame. the 1/8" plate has sliding adjustment, so the jackshaft-to-rear sprocket can be tightened.(of course, there is some chain adjustment at the rear dropout, but it also affects the primary chain on the right side.)

each engine has entirely separate controls. at rest, each clutch lever is pinned, so the bike is freewheeling. one lever is unpinned, then one engine is bumpstarted(or pullstarted at the jackshaft with the rear tire off the ground). with the 2nd engine primed and ready to fire, its clutch lever pin is released. the running engine will bumpstart the 2nd engine. now both engines are warming up, with the rear tire off the ground. when ready. both levers are pinned, and rear tire is placed on the ground. the rider pedals a short way and engages one or both engines.

if one engine falters, or whenever the rider chooses to, either engine's clutch lever can be pinned to remove the engine from the drivetrain. if one engine dies, disengagement will allow the rider to drive home under power.

the builder could also choose an 80cc engine for torque, and a 48cc engine for rpm and better gas mileage. at any given speed, the 80cc engine could be disconnected, and the smaller engine can wind to higher rpm or attain better gas mileage.

with so much low-end torque and more clutch area on tap, one MIGHT be able to pull away from a standing start. however, it would be prudent if the driver pedals a few feet before engaging one or both engines.

centrifugal clutches would definitely be advantageous and convenient, especially at startup and while idling. personally, i just want to finish the project and enjoy the ride.

Myron