This episode of NoPermit's crazy schemes is brought to you by procrastination on editing an english paper. Sitting in study hall day dreaming about things with pistons that go fast has caused me to cook up this wonderful idea. A while back my grandad gave me an old ww2 drone engine just to mess around with. He had no idea what type it was, I messed around with it, figured out how it all worked, and it has sat since then.
Today I was looking on at some cafe racer pictures and noticed the bmw r100 has a flat twin like the drone engine. How possible would it be to create a drone-engined-shaft-driven-motorcycle?
Upon further research I figured that the engine is a Righter 0-15, with somewhere around 6-7 hp. Is this too little to have due to the parasitic nature of a shaft drive system?
This has been purely an exercise in engineering theory for me; and highlights the fact I need to find a project. Either way I would like to see this motor run again, it was surprisingly clean and would just need a carb rebuild and a new ignition system, which will probably be a PITA to source.
Robbie
UltraDork
2/13/17 9:57 a.m.
Should be plenty for a motorcycle, but maybe not a fast motorcycle.
Keep the bike as light as possible.
Any gearbox planned?
Or...sell that drone motor to a collector for serious money and then buy a "real" motorcycle project.
Robbie wrote:
Should be plenty for a motorcycle, but maybe not a fast motorcycle.
Keep the bike as light as possible.
Any gearbox planned?
A gearbox would be helpful to get the most out of the engine, but it would be a little difficult due to the engine having been used to drive a prop. I was thinking a very lightweight direct drive system.
fanfoy
Dork
2/13/17 10:47 a.m.
For an engine like that, the best transmission would be a Torq-a-Verter. But I have no idea how you would implement that in a longitudinal application
In reply to fanfoy:
Easy, put the boxer sideways anyway! Somebody thought it was a good idea:
I guess it would depend on the drone donator. Is it like the first on or the second engine? Is it German or American? Any identifiers on the engine, the carb or block?
It would be easy enough to rob a drive shaft & swing arm from a bike, Vigaros are cheap/free.
In reply to 914Driver:
It looks nearly identical to the first one
This would be a good foundation for a brass era or or pre WWI bike tribute.
RossD
UltimaDork
2/13/17 11:47 a.m.
Or a cycle cart based on a Morgan 3-wheeler
I wonder how many horses are in there, enough to propel a bike?
In reply to 914Driver:
That was my issue, it's around 7
In reply to NoPermitNeeded:
If you want a weird sideways setup like that Midual, you could probably do it with a long enough "pit bike" type frame, although I think it would be cooler to get a moped for the lightweight suspension pieces and "cafe" looking wire wheels and make your own frame.
7hp will move it just fine if it's light enough, a Grom makes about 9hp and they can do 55mph.
To help keep it light and simple, use one of those variable belt drive transmissions. They were used on snowmobiles and formula 440 race cars. It's a belt and two pulley's that change based on the torque or something, maybe magic....
The exhaust could be a tad tricky, might not need a horn...
Might not work great, but it could be crazy fun, and you would have the only one.
upon further research using the interwebs, I have made a wondrous discovery. This is, instead of a 6 hp, a whooping 22 horsepower engine.
https://www.youtube.com/watch?v=quaPqj6dWZI
if anyone is interested in seeing one run. The dude in this video is also using a non-standard carb; which, after looking at the archaeic little bugger on the one I have, seems mighty appealing.
stroker
SuperDork
2/13/17 6:33 p.m.
WHAT THE BERKELEY IS THAT???
In reply to stroker:
magic flat-12 airplane motor? 
In reply to stroker:
The googler says 805ci 450hp Franklin drone engine. I need one for a Brooklands style tank car thing that I have in my imagination
I think (but am not sure) that drone engines like that are set up to run at a constant speed, you may have to adapt a different carburetor to get it to work on a bike.
IMO a better use for an engine like that would be a 1/4 scale RC piper cub.
Hot Rod or Car Craft once featured a motorcycle built from a beach cruiser type bicycle. The builder I remember even fashioned the hand grips out of wood from an oak pallet, that type of thing.
It was beautifully crafted and about perfect for an engine like that.
I'll try to find it now...
Cant find the bike but it looked like a very early Indian. Can't remember if he used a propane torch tank for a gas tank or if it was a genuine original.
Anyway, it looked like this;
[URL=http://s265.photobucket.com/user/derekrichardson/media/IMG_5181.jpg.html]
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Take one $150 Walmart Cruiser bike and proceed from there.
stuart in mn wrote:
I think (but am not sure) that drone engines like that are set up to run at a constant speed, you may have to adapt a different carburetor to get it to work on a bike.
the way the throttle body is setup makes me think this is true, now what kind of carb? Something off a Chinese dirt-bike?
