opposed-piston engine

[ uh-pohzd-pis-tuhn ]

noun

1. a reciprocating engine, as a diesel engine, in which each cylinder has two pistons that move simultaneously away from or toward the center.

Word History and Origins

Origin of opposed-piston engine¹

First recorded in 1965–70

Example Sentences

The Chieftain also has a six-cylinder opposed-piston engine, but it’s mounted in the rear, 19 liters large and puts out over 600 horsepower.

From Fox News

Called the "opposed-piston engine," it is supposed to be 30% more efficient than a conventional diesel engine, 50% more efficient than gasoline engines with 60% fewer parts.

From Scientific American

This “opposed-piston” engine design is from far new – it’s been deployed as widely as by the German aircraft company Junkers for a pre-WWII aircraft and for any number of stationary power-generating applications from the 1930s to today.

From Forbes