By James Wynbrandt
July 31, 2013 - Diesel power is one of the hopes of alternatives to gasoline-powered engines, but the heavier construction diesel engines require makes aviation applications problematic. At the Innovations Pavilion here at EAA AirVenture Oshkosh, Engineered Propulsion Systems (EPS) of New Richmond, Wisconsin, is showcasing the Vision 350 engine, prototype of a lightweight diesel aircraft powerplant in the 350-hp range that is small enough to fit into the cowls of current production single-engine aircraft.
What sets the Vision 350 apart from other diesels, said Steven Weinzierl, vice president/CTO, is that EPS figured out "how to make it compact, but strong." Despite its relatively light weight, its crankshaft is cast-iron, not aluminum. "We have a configuration that keeps it small and short and allows us to be weight competitive," Weinzierl told AirVenture Today.
EPS has already approached several OEMs about using the engine in new aircraft, and is also exploring the potential for retrofit installations. For its certification program, the company recently bought a Cirrus SR-22 aircraft and will install a Vision 350 to conduct flight testing, commencing in about 90 days. Record-setting pilot Dick Rutan will fly as test pilot.
"This is truly a 21st century modern engine, and I was adamant it be put in a 21st century composite airplane," Rutan said. "It's the engine that will save general aviation."
Rutan based his assertion on the engine's ability to run on a variety of fuels, removing reliance on 100LL, and its geared design, allowing the prop to deliver full power at lower rpm (2200-2300 rpm) and reducing sound levels in an increasingly noise-sensitive world.
Rutan came to the program after Weinzierl wrote to his brother, Burt Rutan, about the engine. "A week or two later, Dick Rutan called and said Burt had passed along the letter," Wienzierl said. He and company president and CEO Michael Fuchs arranged to meet in Dick in California for half an hour, a meeting that stretched into six hours.
The EPS diesel can be configured for low and high altitude fixed-wing and piston helicopter applications, and principals say they are currently in discussions with three potential OEM launch customers, and that the company has a provisional purchase orders for more than 1,000 engines in its second year of production, at a $100,000 price point.