Mazda's five-decade-long, largely futile efforts on behalf of the rotary engine demonstrate how difficult it is to unseat the conventional piston engine. Yet new concepts continue to emerge, ...

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, ...

Earlier this year, we wrote about the OPOC engine from EcoMotors. Since then, we've discovered another opposed-piston engine, from Achates Power in San Diego. The EcoMotors engine is a module ...