"Throughout the 20th century, when the utmost fuel, weight and volume efficiencies were required to propel aircraft, ships and vehicles, an unconventional type of compression ignition engine was used: opposed-piston engines," Achates states on its website.
The California Air Resources Board (CARB) provided $9 million to CALSTART, a clean transportation catalyst group that's managing the project. Achates Power will provide the engine and is leading a project team of Aramco Services, BASF, Corning, Dana, Delphi, Eaton, Faurecia, Federal Mogul, Honeywell and Litens joined also by the Southwest Research Institute.
This 10L opposed-piston diesel will be roughly equivalent to a 15L four-stroke, according to Mihai Dorobantu, director of technology planning and government affairs at Eaton Vehicle Group. Eaton technology will manage the precise airflow needed for the opposed-piston engine with a Twin Vortices Series (TVS) air pump/ charger—belt-driven so far in this demo, though there are other options—and the company is developing a new TVS component for the purpose.