Achates Power and Aramco to co-operate on opposed-piston engine projects

15 January 2018

Achates Power and Saudi Aramco’s US-based subsidiary Aramco Services Company announced a joint development agreement providing the framework for the two companies to work together on a series of opposed-piston (OP) engine projects.

The first result of this agreement is the demonstration vehicle revealed at the 2018 North American International Auto Show (NAIAS) in Detroit—a light-duty truck with an opposed-piston gasoline compression ignition (OP GCI) engine. Achates Power is showing the light-duty demonstration pick up truck in the Aramco display.

The pickup truck powered by the 2.7 L Achates OP GCI engine is estimated to achieve 37 mpg, nearly five mpg better than the CAFE 2025 requirements for a vehicle of a similar size, according to the company. The engine produces 270 hp and 480 lb-ft of torque. Achates projects that this performance can be achieved at a cost $1,000 less per vehicle than the technology roadmaps currently considered by OEMs.

“We chose to demonstrate our ultra-clean, ultra-efficient OP Engine in a full-size light-duty pickup truck because of the significant need and opportunity for improvement in this segment. These trucks are driven more miles, sold in higher volume, consume more fuel and emit more CO2 than other light duty vehicles,” said David Johnson, president and CEO of Achates Power. “An opposed-piston engine is 30-50% more fuel efficient than comparable diesel and gasoline engines”

The Achates opposed-piston engine is engineered to achieve superior thermal efficiency by virtue of its lower heat losses, improved combustion, and reduced pumping losses. The OP engine eliminates the cylinder head for an improved surface-area-to-volume ratio of the combustion chamber for reduced heat transfer and rejection. In addition, conventional engine valvetrain and related components are eliminated, and due to the architecture the OP Engine offers a reduction in the aftertreatment system size and cost—a comparison between the 2.7 L OP engine and a comparable V6 with supercharger shows a part reduction of more than 60%, enabling an approximate 10% cost reduction, according to Achates Power.

The OP GCI engine was designed and developed by Achates Power with a $9 million award from the Department of Energy’s ARPA-E, along with partners Delphi and Argonne National Laboratory. Testing of the OPGCI engine was conducted at Argonne, and Achates Power facilities in San Diego. Development and testing of the new 2.7 L engine will continue at Achates Power facilities, and at Aramco Services research center in metro-Detroit. Based on current testing, the engine is anticipated to be fully integrated into the vehicle and drivable in late 2018.

Source: Achates Power