View Full Version : GL/CX 650, just curious.
09-20-2006, 12:14 PM
I didn't find anything after doing a Forum Search, so I figured I'd ask. After dinking around with my son's motorcycle, I'm was wondering if anyone has ever strapped a Honda CX/GL 500 or 650 engine on a gyro. I've seen a 500 on a Teenie Too and a 650 on a Trike (way back before they were called trikes!) Strip off the tranny and you have a really compact unit with lots of performance parts available. I suppose the radiator may scare some people off.
09-20-2006, 12:36 PM
I have often wondered that myself, the only problem that I would forsee with out actually having one here to look at would be the oil routing through the transmission. I know that they have done BMW conversions for trikes and such, as well as moto-guzzi conversions that have been used on the UAV's used by the military.
What is the weight of the engine? and would the clutch being on the front of engine be a problem? I always thought that the gold wing engine would be a sweet conversion, but again they may just be too heavy. Very interesting.
09-20-2006, 01:52 PM
I'll probably have a better idea after Saturday. I'll should be making a parts run for my son and a couple of other GL and SR 500 owners. I know where in the pile a bunch of the Honda water-cooled twins are hiding. Mostly disassembled, so I should have a rough idea of the weight. It was just a thought and I'm no expert on this engine,...yet. It just looks really simple in the parts diagram.
09-20-2006, 02:18 PM
The CX 650 turbo would be nice!
10-01-2006, 10:57 AM
I've done some more work with the GL500. The 650 turbo would be a great little aircraft engine. Leave the clutch on it and you can work on the engine while it's running and have the prop disengaged. I figure with the radiator on it the GL500 sans tranny is around 100lbs. Jeez that's a simple engine. I looked at a wrecked one yesterday that the savalge yard had been told the odometer had already rolled over once. It showed over 86,000 miles and still sounds good! It fired right up and ilded just fine. (It looked like the previous owner backed over it with a car.)
Think torsional resonance!
10-01-2006, 05:37 PM
A cheap harmonic balancer and good Lord mounts would cure that.
10-01-2006, 06:12 PM
The question is will they hold up to constant 75% to 100 % power range that most gyros require. I know motorcycle engines have good power to weight ratios but, they are only used at full power for short bursts.
The best suited for this would seem to be a boat engine since they have a simular life. I'd love for someone to try the new Honda seadoo type engine. I called around about getting a power head but all the dealers wanted a hull number or they would not sell you an engine.
10-02-2006, 02:49 AM
As I recall, my old air-head BMW twin turned 4200 RPM at 80 mph and would do that from one side of the country to the other, day after day, 16 hours a day. It's what they were made for...
Speaking of the Guzzi application, I am seriously interested in the idea, since I have a perfectly good 1100cc fuel injected engine sitting in a bike I never ride. I could take a page from Charlie Mara's book - ride the bike to the hangar, strip the engine out and e-bay the rest, probably end up making a profit. I've found good pictures of the 750cc engine with a prop drive on it, but no mention or clues about where the drive came from.
Oddly enough, I was wondering earlier today why gyros don't have a clutch between the crankshaft and prop, especially in the BMW version. The old clutches were single dry plate, hell for stout and didn't take up much room between the cases and transmission. Is there some particular reason why clutches aren't needed or desirable?
10-02-2006, 04:52 AM
I would venture clutchs of the auto type would need a flywheel, pressure plate, throwout bearing, and some means of accuatating it, then the redrive would need sometype of input shaft. Motor cycles mostly use a wet type clutch, with a clutch basket to hold multiple plates(half friction, half drive) many springs and a similar throwout bearing. Most would add unwanted length and weight to any setup not to mention something else to worry about. Centrifical clutch setups like the rk 400 for the rotax c box is a very nice unit and simple. Carey
10-02-2006, 09:18 AM
Mike, this engine is best know for the Silerwings, baby Goldwings that could, and still can, cruise at highway speeds all day long. None too shabby for a 500cc bike with two people on it. The 650 was better and the CX650 just doesn't quit as long as it's mainted. Poor maintanence killed a lot of the turbos. From everything I've been able to find out, this looks to be the best series of engines Honda has ever built. Since this is the first Honda anything I've had, I can't say for sure. I just find it a very interesting power plant and very compact.
I just found out there is an 83 GL650i with with 6,800 original miles for sale in Aiken, SC for $2900.
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