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sweet!
 

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I havnt seen that before. I have seen a heli made with a CX. I have to admit, I didnt watch the whole vid. But, looked cool.



Michael

 

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Ultralights always sound as though they're approaching mach 1, while in reality they're just loafing around. Very cool video and good use of a dependable engine.
 

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I've always considered the CX and the Moto Guzzi to be just two cylinders of a radial engine. Sound is great. Notice pod filters, NO air box, and no H pipe.

Cheers, 50gary
 

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That looks like so much fun. I bet he could get even more aggressive with the prop an get his cruising RPM closer to 5K.
 

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Be interesting to see what instructorpilot has to say about this one...



I was trying to figure out his blade tip speed... too much math, not enough coffee...



I could not hear most of his narration with the wind noise ( he shoulda hired a pro sound recordist
)



That propellor does look a bit Un pitched... as in something off a race plane... I think he did say he would go to an increase in pitch which would slow him down on the revs.
and what has he done with the xmission?





I wanna use a CX motor to power a boat. I don't like heights...
 

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I wonder how well it works as a glider? If he has a CDI type engine in it, a short in the charging windings on the stator will kill the engine dead, just like hitting the kill switch.
 

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I took a look at the forum discussing the plane. As well as the prop change he was considering using 2nd as well as third gear. 1 1/2 gallons per hour fuel consumption at cruising speed, 6000 RPM. Wonder how fast cruising speed is - would be interesting to compare ground fuel mileage to aeronautical knots per gallon.
 

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Sweet!



If I was him, I would have tried to get a 650 motor, same weight, but with 30% more torque and HP that comes in a little lower in the rpm range.



At 6k rpm on a 500 you are probably getting about 40hp, on a 650 I bet you would be getting better than 55hp.



Also, he says it is a GL500 motor, so he is running a TI ignition and has a Volt meter.

I'd trust it.



EDIT: He should put some Harley stock mufflers on that thing.

the back pressure would do it good and the Sound would be cut by ~70%. it would add about 30# to the plane though.

Still, Soooooo much quieter.
 

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Sweet!



If I was him, I would have tried to get a 650 motor, same weight, but with 30% more torque and HP that comes in a little lower in the rpm range.



At 6k rpm on a 500 you are probably getting about 40hp, on a 650 I bet you would be getting better than 55hp.



Also, he says it is a GL500 motor, so he is running a TI ignition and has a Volt meter.

I'd trust it.



EDIT: He should put some Harley stock mufflers on that thing.

the back pressure would do it good and the Sound would be cut by ~70%. it would add about 30# to the plane though.

Still, Soooooo much quieter.


He also needs longer intakes to make the carbs work correctly.
 

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He also needs longer intakes to make the carbs work correctly.




Looks like the Intakes are stock, but yes, I think it would be worth while to find a way to mount a stock airbox on it too.

It would look a little funny, but we all know that the straight pipes and pods on these actually Kill max power and mid-range. even after rejeting.



Put harley or stock mufflers and get a GL500 or CX500 air box mounted up to it and he could expect better power and torque at the 6000 rpm he has targeted.
 

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Hmmm, I am looking for an engine that would work on my airplane project... Mine will be a little bigger than that airplane, maybe two GL engines? Or, maybe I should steal the engine from my Valkyrie?



 

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I have always said that motorcycle engines would be good for airplanes. First their light. Second they have a high power to weight ratio. The beauty of the CX/GL engines is the fact that their liquid cooled. The problem with air cooled engines in airplanes is that when you throttle them back they cool off too fast. This is called shock cooling and can actually damage the motors. This guy used a GL500 engine so he has the regular electronic ignition not the CDI. I see no problem with the pod filters as long as there is an exhaust to match, which there is. It's a bit loud but no more than any other small piston powered airplane. Torque is really not a factor on an airplane engine because you operate them at full power for a long time, such as in the climb. The ideal RPM would be where the horse power curve peaks. Ideally the torque curve should peak at the same time if it's tuned correctly. The fact that he's running through the gearbox shouldn't be an issue as long as he keeps the oil changed. The only weakness is the clutch. He really does not need one. I would remove it, and just use a device that replaces the clutch and works more like a straight drive. Remember the only reason we have a clutch is to facilitate shifting, which this guy does not do. I have seen many BMW airhead conversions for airplane use. The BMWs of old had a crankcase that was separate from the tranny and used a dry clutch. Even these needed a reduction gearbox. The old Cessna 150 ran at 2700 rpm max. Standing still at full power gave you 2300 rpm. as airspeed went up, so did rpm as the prop unloaded. I don't know where the horsepower peak is on a CX engine. I do know that the torque peaks at a somewhat lower rpm.

I think to calculate blade tip speed you need to know how big the propeller is in from tip to tip, from that you could calculate the circumference, and using propeller rpm, which in this case will be different than engine rpm, you can calculate tip speed. Listening to it run though I don't think it's any where near M1.
 

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Hmmm, I am looking for an engine that would work on my airplane project... Mine will be a little bigger than that airplane, maybe two GL engines? Or, maybe I should steal the engine from my Valkyrie?
If you are building it from a kit, it should have a spec for the HP rating of the motors you want to run.



like say 40 to 80hp or 65 to 90hp



If it will fly with only a 50hp, you Might get by with a 500cc, but you would probably want to run the 650cc.
 

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I saw an old Pete-N-Paul the other day. This ws a kit plane back in the 30s that used a Model A engine. It only had 40 horsepower. There are also countless planes that fly quite well with VW aircooled engines.
 
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