Just about every piston engine is defined by two basic measurements: bore and stroke. Bore is the diameter of the cylinder. Stroke is the distance the piston travels from bottom dead center to top ...

Sometimes, the terms boxer engine and flat engine are used interchangeably, even though the two are not the same. What's the difference? Which one is better?

Horizontally-opposed engines are often referred to as "boxer" engines because the motion of the pistons sort of resembles a boxer, punching. Really, though, if any engine should be named for a boxer, ...

1. EcoMotors is developing high-efficiency engines — specifically the unique opoc (Opposed Piston Opposed Cylinder) engine — for use in cars, light trucks, marine applications, agricultural vehicles, ...