Achates Power Inc., which is developing new diesel engine technologies at its Sorrento Valley headquarters, has opened an office in the Detroit metro area.

The 4,000-square-foot customer application engineering facility is in Farmington Hills. Achates said it plans to hire 12 new engineers and program managers immediately, and plans to have a staff of 20 in place by the end of 2015 “to keep up with the rapid growth in customer demand for the Achates engine.”

Achates makes an opposed-piston engine, where a combustion event at the center of the cylinder drives pistons at either end of the cylinder.