In the midst of all the amazing things that comprise the annal
Oshkosh Fly-In, Aero-TV took some time out at the 2008 rendition to
talk with Eric Barger, President of RotaMax Rotary Engines. This
company is introducing a line of aviation rotaries based on a
long-established, non-automotive design. The company recently
signed a tentative OEM agreement to furnish a twin-rotor powerplant
for an upcoming light-sport aircraft.
The RotaMax engine is a Wankel-type rotary engine, named after
the German inventor Felix Wankel. Instead of conventional pistons
reciprocating inside cylinders with a complex valvetrain, the
Wankel has a rotor shaped roughly like a triangle that runs inside
a housing with an epitrochoidal cavity shaped roughly like a figure
8. The rotor is geared in relation to an eccentric shaft, which is
the equivalent to the crankshaft inside a piston engine. The rotor
covers and uncovers ports as it rotates inside the housing,
enabling four-stroke Otto-cycle operation without valves. The rotor
uses seals as the equivalent of piston rings, including apex seals
at the points of the rotor and side seals on the sides.
RotaMax opines that Wankel engines are inherently smoother and
easier to balance because of the rotary operation. For the same
output as a piston engine, a Wankel will generally be smaller and
lighter and will have far fewer parts, particularly moving
parts. In certain applications even in the 1970s, for the
power produced in the application the rotary had—and
has—favorable fuel economy. Because it has a four-stroke
cycle, the rotary can use the same performance tuning operations,
external accessories, and emissions control devices as a
conventional engine.
RotaMax has particularly high hopes for their future aviation
offerings. They note that 'Aviation Enthusiasts are always
searching for more power! But, they want it with lower emissions,
lower vibration, higher power-to-weight, smaller package. We are
currently working with several manufacturers designing next
generation aircraft for the RotaMax Rotary Engine.'
Though currently not certified, RotaMax explains that they are
doing the work necessary to assure that their twin-spark, twin
ignition engines will conform to the ASTM E-LSA, S-LSA, LSA
protocols... and with enough time and experience, General Aviation
Certification. They feel they have an interesting powerplant for a
number of air vehicles... be they airships, blimps, gyrocopters,
fixed wings, floatplanes or seaplanes, Ultralights, Light Sport
Aircraft (S-SLA), Experimental, Homebuilt Kits, or Helicopters.
RotaMax is currently concentrating its efforts on two aviation
powerplant platforms with two variations of each:
- A Gear-Reduced 650cc Single Rotor Down Draft Engine
- A Gear-Reduced 650cc Single Rotor Side Draft Engine
- A Gear-Reduced 1300cc Twin Rotor Down Draft Engine
- A Gear-Reduced 1300cc Twin Rotor Side Draft Engine