PRODUCTION PROTOTYPE Achates Power is another US company engaged in OP engine development. The company secured its fifth OEM contract in December 2014. Achates engines differ from the EcoMotors designs in having two crankshafts. The cranks are geared together and output passes through a single shaft. Early test engines have met EPA 2010, Euro 6 and Tier 3/LEV 3 emissions standards, the company said. The design enables an increase in volume to surface ratio within the cylinder, preventing heat losses through the engine walls. Furthermore, pumping losses are reduced because of the twostroke design.
At the Detroit Motor Show in February 2018, Achates Power displayed a production prototype petrol, 2.7-litre, six-piston, three-cylinder engine in a Ford F-150. That engine boasts an EPA combined fuel-economy rating of 37 mpg (US) – around 9L/100km. The two-stroke Achates powerplant burns a very lean gasoline-air mixture purely through compression, giving it diesel-like characteristics and claimed thermal efficiency of 45 percent. The company designed and developed this engine with US$9 million in funds from the US Department of Energy’s ARPA-E program, in conjunction with both Argonne National Laboratory
and auto-parts maker Delphi. In Detroit, Achates said it had formed a joint-development agreement with consultant Aramco Services, the Houstonbased US subsidiary of Saudi Aramco, the national oil and gas company of Saudi Arabia. Achates ultimately intends to license its design to vehicle and engine makers throughout the world, said CEO David Johnson, but doesn’t intend to manufacture engines itself. The company reportedly has nine development programs underway with engine manufacturers; some of which could lead to other automotive applications.
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