Engineered Propulsion Systems of New Richmond, Wis., announced passing an important technical milestone in its program to bring an aerodiesel engine to market in the general aviation and military unmanned aircraft systems sectors.
Tests conducted at Hartzell Propeller showed that its 4.4-liter, "Flat-Vee" Vision 350 engine was “fully capable of achieving propeller durability” in an array of traditional aluminum and composite propellers, “without the need for further engine vibration dampers,” EPS said.
Those results vindicated innovative features of the 350-horsepower, liquid-cooled engine that were designed to counter vibration and make the engine “smoother running than any diesel engine and many current gasoline GA engines tested.”
“This engineering milestone, completed in collaboration with Hartzell, is a significant step forward in bringing our diesel engine to market,” said Steven Weinzierl, EPS’s vice president and chief technical officer. “When we began this project, we knew that designing a high-performance diesel to work reliably with propeller and gear reduction systems would be a technical challenge,”
“It’s a distinct departure from prior engine designs, and we believe what Hartzell has now confirmed: induced vibration is no longer an issue,” he said.
Hartzell was encouraged to see that stresses on propellers were “lower than most engines we have surveyed,” said Bruce Hanke, Hartzell’s vice president of engineering, commenting in the Feb. 12 announcement.
EPS hopes that the 657-pound engine, which can run on Jet A, JP-8, or diesel fuel, will earn a 2,000-hour time between overhaul (TBO). Fuel efficiency will “easily” offset the engine’s higher weight than gasoline-burning engines of similar power, EPS said.