7-Cylinder Bikes

[davemoore]

Sort of related to this post but not quite:
http://www.bmwlt.com/forums/showthread.php?t=4648&highlight=radial

Here's a couple 7-cylinder radial engine motorcycles with Rotec engines - imagine the looks you'd get riding down the street on one of these babies. The articles speculate on their origins - if you find something more informative, please post.

"Harley" version:
http://thekneeslider.com/archives/2006/05/11/radial-engine-motorcycle-2/

"BMW" version:
http://thekneeslider.com/archives/2006/05/10/radial-engine-powered-motorcycle/

[messenger13]

SWEET!!! Now that's a chopper I wouldn't mind riding! http://www.r1-forum.com/forums/images/smilies/yesnod.gif

http://thekneeslider.com/images/radialbike.jpg

[dshealey]

Imagine the torque steer you would get when throttling up! Just sitting there if you were not prepared and holding on the bike would try to lay over on it's left side when you blip the throttle.

Also, they sure did not plan on using the full torque capability of the engine, since the main output (propeller) shaft is covered, and they are taking the power off from the accessory drive section at the rear of the engine. Those drives are meant for pumps, alternators, etc..

But, who would expect that art project to be practical anyway. :D

[blankshot]

I bet that sounds great!

[mneblett]

Imagine the torque steer you would get when throttling up! Just sitting there if you were not prepared and holding on the bike would try to lay over on it's left side when you blip the throttle.

Also, they sure did not plan on using the full torque capability of the engine, since the main output (propeller) shaft is covered, and they are taking the power off from the accessory drive section at the rear of the engine. Those drives are meant for pumps, alternators, etc..

But, who would expect that art project to be practical anyway. :DCool -- that would be like riding four boxers at once!

Here's an even more tantalizing prospect: Some aircraft radials, the crank didn't rotate -- it was bolted to the firewall, and the *entire engine assembly* (case/cylinders/etc.) rotated about the fixed crank (the propeller rotated with the engine). Wouldn't it be *cooool* if this one was set up that way, maybe with a bull gear/pinion power take-off at the rear face of the engine case -- I'd LOVE to see it idling with the engine spinning around!

[dshealey]

Cool -- that would be like riding four boxers at once!

Here's an even more tantalizing prospect: Some aircraft radials, the crank didn't rotate -- it was bolted to the firewall, and the *entire engine assembly* (case/cylinders/etc.) rotated about the fixed crank (the propeller rotated with the engine). Wouldn't it be *cooool* if this one was set up that way, maybe with a bull gear/pinion power take-off at the rear face of the engine case -- I'd LOVE to see it idling with the engine spinning around!

Yep, that was the first development of rotary engines, Le Rhone I believe was the one used in the Bleriot and the early WW1 planes. No throttle either, just an on/off switch. That is why you hear the Brrrrp-Brrrp-----Brp--Brrrrrp sound in the films of the restored WW1 fighters.

They had wicked torque roll problems with those, and turning them was a real witch, as rudder applied in one direction caused the nose to go up, the other direction it went down due to the gyroscopic precession from that huge gyro on front.

When they first developed those engines they incorrectly thought they had to spin the cylinders to cool them properly.

Also, they used Castor Oil for lubricant, causing the pilots to have NO problems with constipation. :D :D

Thinking about your using one on a motorcycle. Imagine if you leaned it a little too far! From 40 MPH straight ahead, to 90 MPH going right or left. :D :D :D

[Steve_R]

Some aircraft radials, the crank didn't rotate -- it was bolted to the firewall, and the *entire engine assembly* (case/cylinders/etc.) rotated about the fixed crank (the propeller rotated with the engine).

The only aircraft I can remember seeing with that style engine was a WWI Fokker Dr.1. The Red Baron flew one. There is one that is still flying out of the Old Rhinebeck Aerodrome and looks like the picture below.

http://www.oldrhinebeck.org/collection/airplanes/Fokker_Dr.1_John_B.jpg

Click here (http://www.acepilots.com/wwi/fokker_triplane.html) for more info on this aircraft.

[messenger13]

I'd LOVE to see it idling with the engine spinning around!Would YOU actually sit on the thing while it was idling?!?! :eek:

[mneblett]

Would YOU actually sit on the thing while it was idling?!?! :eek:Not a snowball's chance! I said I'd like to LOOK at one -- Momma didn't raise no fools (and I didn't have foster parents! http://www.bmwlt.com/forums/images/icons/icon10.gif)

Man, just imagine the torque reaction! When I blip the throttle on the R75 or R100 at idle, I feel the bike lean against my inner thigh in response -- blip the throttle on that thing, and it probably would go straight through the thigh on it's way to the next county!