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Old Apr 27, 2009, 08:09 PM
I fly ghetto stuff.
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Greece
Joined Aug 2007
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Question
Could a Nitro engine move a full size bicycle/moped?

For the lack of a better thread to post this (e.g. one exclusively for nitro engines), I decided to ask this in the RC Motorcycle threads.

Considering that even .12-.18 nitro engines are capable of delivering more than 1 HP, while bigger ones easily reach 1.5 or 2.5 HP, I always wondered if they could be used to power a bicycle or a lightweight moped like the Piaggio Ciao, which uses a 2-stroke 1.45 HP engine anyway.

Some of the issues I can think of are:
  • Torque. Undoubtedly the heavier 50 cc gas 2-stroke engine will be optimized to have a greater torque than a small nitro engine, but I couldn't find exact figures for either. Dunno if a small nitro engine could even make a moped or heavy bicycle budge, if not at high RPM.
  • Gearing. With a max. RPM ratio of 6:1, different gearing would be required, so again I don't know if a small nitro engine could be linked to components able to handle the stress of a much heavier vehicle (40 kg empty + driver in the case of the ciao), especially during acceleration and engine braking.
  • For some reason, the thought of a combined 120 kg of vehicle + driver forcing compression in a small nitro engine during engine braking doesn't sound very good for the engine...
  • Fuel economy. The ciao can cover about 50 km/liter at a constant speed of 40 km/h (maximum legal speed for mopeds in Italy), I'm no nitro expert but apart from the fuel being more expensive per-se, I never heard of them being particularly efficient.

That's about all I can think of. Are there any practical accounts of something similar?
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Old Apr 27, 2009, 09:38 PM
Inciting Riots
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Yamaha YSR - 50cc and about 7 horse power. Would push rider and machine to about 45 miles per hour grinning ear to ear the whole time.


"Hey, I got it up to H that time" The speedo only went so high so we used to pick the next available printing which was the MPH. Never failed to be some form of stupidity because it was such a small and road legal machine! Stoppies - YUP! Wheelies - not in stock form. Circles in about a 4 foot diameter with the thing leaned over so far you couldn't fit your leg. When I bought it it came home in the back of a friends Volkswagen Rabbit with the seat folded down.
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Old Apr 27, 2009, 11:08 PM
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United States, Death Valley
Joined Aug 2003
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Absolutley they could.

But, the engine would wear out about 10 times faster, and need 10 times more gear reduction.

Just like you could us a 5000 HP nitro dragster engine in a tugboat, geared right it would produce the same thrust as a 5000hp diesel, but which you think would be more efficent and last longer

On the other hand, which you think would be lighter in weight
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Old Apr 28, 2009, 08:08 AM
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USA, FL, Fort Myers
Joined Jun 2008
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i bet this one could !! but may not be practical but too cool not to show !!!

V 12 Modellmotor RC Engine the original Video ! (2 min 24 sec)
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Old Apr 28, 2009, 09:53 AM
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Memphis, TN USA
Joined Apr 2009
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i know some will not like this but horsepower is just a marketing scheme..Torque is where the real power is. horsepower is a calculation for marketing.dynos do not measure hp they measure torque and hp is an estimated calculation...you get what you pay for..this is true with full scale bikes and cars too...mike
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Old Apr 28, 2009, 12:17 PM
I fly ghetto stuff.
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Greece
Joined Aug 2007
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Any indicative figures for nitro engines? Many modern 50cc scooter gas engines can produce torque in the 2-3 N.m region @ 5000-6000 rpm, while typical 1000-2000 cc gas engines for cars are in the 100-200 N.m (or 10-20 kg.m) region.
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Old Apr 28, 2009, 12:48 PM
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sure the rc motors are in the .001 to .09 nm range
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Old Apr 28, 2009, 01:27 PM
I fly ghetto stuff.
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Greece
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So little? :-/
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Old Apr 28, 2009, 01:32 PM
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its such a small stroke i dont think it could produce much more unless it is superchared or maybe i mini nitros system would be cool for more torque...
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Old Apr 28, 2009, 01:59 PM
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Yep not enough torque.The poor little motor would have a heart attack.
You could look into the 1/4 boat motors.Some of them are big 90cc 2 stroke motors that run on the same fuel as the little nitro motors.But think about this,The nitro fuel cost like 30bucs a gallon. You'd be better off with a chainsaw motor or something.
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Old Apr 28, 2009, 02:42 PM
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United States, VA, Mechanicsville
Joined Oct 2006
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You need to check this out. Some nut (yes I want to build one...) put a small Wren Heli Turbine on a scooter. Looks like he just needs to gear it better. They are rated at something close to 10hp.

Sam's Jet Turbine scooter II (1 min 25 sec)


I ordered the new Wren 44 heli turbine, rated at just under 7hp.
I was thinking of putting it on my Cannondale 4000sx, would be cool but loud.

I wanted the Jetcat SPH-5A two stage helicopter turbine, but it is 3 inches longer than the new small wren that I can put in my Three dee MP XL.
www.jetcatusa.com $4200 on the home page, 10hp.

It can be done.

Laz
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Old Apr 28, 2009, 03:50 PM
I fly ghetto stuff.
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Greece
Joined Aug 2007
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Hmm..reminds me of turbine cars, and even the most finely crafted of those ultimately proved to be a failure. What plagued most designs was poor torque and acceleration, and in general the turbine's poor aptitute to function at continuously variable rpm.

Quote:
Originally Posted by swheels
You'd be better off with a chainsaw motor or something.
Or a moped motor to begin with

How about those multi-cylinder nitro engines then? Some radial designs sound pretty beefy, although it's incredibly hard to find actual figures.
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Old Apr 28, 2009, 05:07 PM
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United States, WA, Puyallup
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several years ago fox made a 2cycle motor that mounted on the back of a bike that ran on nitro, Ha that was back when fuel was $5 a gallon !!
If I remember right the shaft ran against the tire drivng the bike, kind of like the old bike generators.....must have been hell on tires!!!!
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Old Apr 28, 2009, 05:13 PM
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the v 12 in my eairler post may have the torq you are looking for but im sure its a nightmare on a fuel bill !!!
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Old Apr 28, 2009, 07:05 PM
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Quote:
Originally Posted by Velktron
Hmm..reminds me of turbine cars, and even the most finely crafted of those ultimately proved to be a failure. What plagued most designs was poor torque and acceleration, and in general the turbine's poor aptitute to function at continuously variable rpm.



Or a moped motor to begin with

How about those multi-cylinder nitro engines then? Some radial designs sound pretty beefy, although it's incredibly hard to find actual figures.
Yeeaahh that would be the best bet.Besides you can get some of those 2 stroke scooters to haul!!!!!On youtube there was a guy with a 2 stroke scooter motor setup on his mini drag bike.He was beating some full sized sportbikes.
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