Eurocopter has revealed it is evaluating the potential for powering a light helicopter (EC120) with a unique diesel engine developed by US company EcoMotors. A diesel engine could reduce fuel consumption by 40% over a turbine engine, and EcoMotors’ Opposed Piston Opposed Cylinder (OPOC) engine is claimed to be significantly smaller, lighter, simpler and cheaper than conventional diesels.

In this video, EcoMotors chief technology officer explains how the engine works.

The opposing piston opposing cylinder engine (OPOC) concept has been around for years but was never fully developed. FEV and Advanced Propulsion Technologies (APT) was asked by the U.S. Army Tank Automotive Research Development and Engineering Center (TARDEC) to analyze the idea and develop it for use in heavy-tanks.  After completing the proof of concept- it appears the company is on to something.

The OPOC engine uses a two-stroke combustion cycle and delivers twice the power density of a traditional four-stroke. How does it work? Four pistons sit aligned in row with a crankshaft in the middle. Each set of pistons face each other.  This configuration allows for an exceptionally balanced engine with no load on the main crankshaft bearing while running.