FREQUENTLY ASKED QUESTIONS

What does the engine weigh?

The engine weighs approximately 340 lbs. We will have an exact weight very soon.

What is the maximum RPM?

The maximum is 6200 RPM with a 2.17 or 2.20 drive ratio.

What is the Horsepower?

The horsepower is approximately 180 HP but that is a conservative number.

What will this engine fit in?

The demo engine that we have finished fits in a Mustang II cowl made by James Aircraft. The RV6,7 and 9 have larger cowls so the engine will fit nicely in those planes. We are installing the same engine in a Thorp T-18.

Will the engine mount fit in other models of planes?

We will custom fit any engine mount. You would have to supply us with the dimensions and drawings.

What is the cowling?

The cowling is made by James Aircraft and the one we have in our photos is for a Mustang II. They also manufacture cowlings for the RV series of aircraft.

Is the cooling system effective?

Yes, we found that running the engine on the test stand for a 20 minute run produced a temperature in the both the oil and the coolant of 159 degrees.

What is the cost to overhaul the engine?

An overhaul costs about $1000.00 but Tracy Crook at RWS flew his first rotary engine 856 hours and found no appreciable wear on the engine with the exception of the apex seals. The wear on the seals was about 30% of allowable limits. A basic overhaul kit is about $468.00.  The master overhaul kit is about $970.00 The maximum cost for a complete overhaul is about $3500.00 if you need major engine parts but that is very rare.

What about oil injection into the rotor housing area?

The oil injection pump has been disabled and we mix two stroke oil with the gas.  The formula is 1 oz. of two stroke oil to 1 gallon of gas.

What is the TBO (time before overhaul)?

After 856 hours, Tracy Crook found only the apex seals were worn and the wear was about 30% of the allowable limit.

What Mazda engine do you use?

We use the 13B Second Generation.

Why don't you use the Renesis?

We have found a good supply of the 13B Second Generation and have customized motor mounts for that engine.

What is the difference between the Renesis and the 13B?

The Renesis is about 10 lbs lighter that the 13B and the exhaust ports have been moved from peripheral to side port. This lowers the exhaust temperature by about 200 degrees but raises the water temperature. This causes higher temperatures under the cowling.

What is the exhaust system made of?

The exhaust system is made of 321 stainless steel with 2" tubing 049 wall. The system will use slip joints and ball joints.

What is the fuel consumption?

The engine burns between .452 and .456 gallons per horsepower. This compares to any other engine (V8, Lycoming) as it takes a specific amount of fuel to create a specific amount of horsepower.  All the engines burn the same amount to create that horsepower.

What type of gas does the engine use?

The engine uses AvGas or MoGas.  MoGas is much less expensive and is the preferred fuel (you will get longer life from you spark plugs with MoGas) but if you are at an airpoart and all you can get is AvGas, that is not a problem. The engine controller we use on the engines (RSW EC2) is specially designed not to use an O2 sensor so there is no danger of the lead in the AvGas impacting the running of your engine. In fact, there is a long term rotary pilot who uses nothing but AvGas in his airplane.

We do have an O2 sensor in our system, but it is not used by the engine controller.  The O2 sensor is used only by the EM2 engine moniter to moniter and display the mixture. If this sensor is fouled by the lead in the AvGas, the only impact is that the response of the mixture moniter slows done slightly.

 Does the engine have the capability to heat the cabin?

 Yes, you can use the engine water system to heat the cabin.

What about cooling the cabin?

Air conditioning can be installed but with a weight penalty.