The opposed-piston engine has been around for over 100 years and is more efficient in almost every way. The engine has no traditional valves, cams, or camshafts, and no head, so it’s simpler and ...
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, ...