| It is interesting that when you go back into the early days of ultralight aviation you will find that we were using an engine on our Lazair ultralights called a Pioneer. It was manufactured by OMC in Peterborough Ontario. While not designed to be used in aircraft, it was actually a chain saw engine, we none the less adapted it to work on our craft. A number of years later OMC entered the snowmobile industry and spent a small fortune developing a rotary engine. At one point they had a team of over 40 engineers working to develop the engine. Unfortunately just about the time they were about to start production on the engine the snowmobile industry fell on hard times and the project was put on the back burners. Recently a U.S. company RotaMax, purchased the design rights to the engine and using today's technology has started producing and offering the engine for ultralight and light sport aircraft application. Eric Barger President of RotaMax was at Sun N Fun showing a number of aircraft installations that are currently using the RotaMax rotary engine. These included Higher Class Aviation and it's Hornet, Sadler Aircraft and the Sadler Vampire. One of the reasons these manufacturers have installed the RotaMax engine on their craft is the simplicity of the design. A single rotor engine has two moving parts, while the twin rotor has only three moving parts! The engine is still a 4 cycle engine, with intake, compression, power and exhaust cycles. It does not use the conventional valves, push rods, camshafts etc. which makes for a very heavy installation. Instead the " Wankel Style" rotary engine uses a triangle shaped piston which rotates around in a circle, with ports in the case routing the individual cycles. This gives the RotaMax engine a very high power to weight ratio. Another advantage is the low cost of maintenance and rebuild on the engine because of the lack of wearable parts, no gaskets, and the simplicity of design. Engine vibration is nearly nonexistent because "it is a rotating mass engine it is perfectly balanced." The engine is liquid cooled using a water pump and radiator, with the type of cooling system used being specific to each application." This means that they system used on a slow moving gyrocopter would be different that that used on a sleek 140 mph light sport aircraft. The RotaMax single rotor 650 cc, 65 HP engine will use between 3 and 4 gallons of fuel an hour, while the twin cylinder 1300 cc engine uses 4 to 6 gallons per hour, again this will vary with the type of application the engine is being used in. All of the RotaMax aircraft engines are equipped with dual ignition systems. Currently the single cylinder engine is only available in a carbureted version, with the twin cylinder 1300 cc engine being fuel injected. The RotaMax engines have a very flat torque curve which means you can bring the horsepower use back on the engine and still do the same work. Less horsepower means less fuel burned. The RotaMax 1300 cc twin rotor engine has a top RPM of 4750, with cruise RPM being 4250. However RotaMax is working closely with Rotary Aircraft Engines of Utah to develop horsepower/torque engine application for specific aircraft. Another unique feature of the RotaMax engine is that it uses a "lost oil system." Regular 30 weight oil is injected into the engine, and is burned off in the combustion cycle. This means you do not have an oil pan, you do not require any oil changes, no oil filter, and no waste oil to dispose of. The RotaMax engines come with a standard charging system of 32 amps but an optional unit of 45 amps is available. The engine uses an oil bath spur gear reduction drive, with ratios from 1.9 to 2.7 available. RotaMax is also developing belt drive systems to fit various applications. A number of exhaust systems are being developed, all of the systems are made from stainless steel due to the higher exhaust heat that the engine produces. Eric reports that the factory which has been producing engines for over 3 years now for other applications such as hovercraft, dirt bikes, motorcycles, and ATV's has the capability of producing 150 engines per month, with the ability double this if necessary. Nathan Oldham of Rotary Aircraft Engines is the master distributor for the RotaMax aircraft engine. His company is the one that involves itself with the aircraft manufacturer to develop the complete installation requirements for each application. His company is also responsible to training the aircraft manufacturer on the differences between what they have been doing in the past and what is different or what needs to be changed to ensure continued safety and reliability of a RotaMax engine installation. As more and more customers become more familiar with the RotaMax series of aircraft engines Nathan will work with the aircraft manufacturer to provide a complete installation package for specific aircraft. One RotaMax conversion on display at the show on a gyrocopter actually dropped the engine installation weight from what was being used by 100 lbs., in addition to supplying more horsepower. Nathan indicates that one of the goals of Rotary Aircraft Engines is provide "a lower cost aircraft engine alternative, with a significant power to weight ratio increase, with lower maintenance and operating costs." For more information: | 
