Nitro Powered Radio Control Planes
Glow fuel engines also termed nitro power engines are used to power radio control aircraft.
These engines run on methanol mixed with oil and nitro methane. The engine is kept running via a glow plug.
These have been for some years the most popular choice of power systems for rc planes and heli's.
So much so that a large number of manufactures of rc planes refer to there rc models by engine size required to fly it as opposed to weight or actual size.
The 40 size 2 stroke glow engine is the size most popular and there is hundreds of planes and kits designed around this size of motor. The 40 or .40 is the cubic inch of the engine. In the .40 size this is less than a half cubic inch displacement.
These rc planes are considered to be the standard size when referring to fuel powered models.
For the modeler this has helped greatly with keeping the price down on this size of plane, there are literally thousands to choose from, lots of competition keeps pricing at its best.
The 40 size 2 stroke is also the cheapest engine in the fuel power arena.
The benefits of glow power over other types of engines is there power to weight ratio, although electric technology is catching up fast.
Glow fuel has been used as fuel in the rc plane hobby to power some pretty unique engines such as the wankel, but the majority are either 2 stroke or 4 stroke. Both types run on glow fuel and use a glow plug.
In a 2-cycle engine the fuel/air mixture (as metered by the carburetor) is forced into the combustion chamber during the down stroke of the piston. During the upstroke the mixture is compressed and when the piston reaches reaches the top of its stroke, the glow plug ignites the compressed gases, forcing the piston down. On the way down exhaust gases escape through the exhaust port while the fuel mixture enters the chamber. The entire power cycle takes 2 strokes of the piston
In a 4-cycle engine the fuel/air mixture (as metered by the carburetor) is brought into the combustion chamber during the down stroke of the piston through a valve operated by the crankshaft. On the upstroke the valve closes and the mixture is compressed. When the piston reaches the top of its stroke, the glow plug ignites the mixture forcing the piston down. On the next upstroke of the piston, a second valve opens and allows the exhaust gasses to escape. The fuel mixture again enters on the down stroke. The entire power cycle takes place in 4 strokes of the piston.
Glow engines manufactures offer sizes from .09 cubic inches to 2.5 cubic inches in the off the shelf format. There is also many specialty companies producing engines in a variety of performance enhancing techniques.
Standard 2 stroke glow engine.
Standard 4 stroke glow engine
Couple of unique types
radial, flat four and wankel