Sandia National Laboratory led by Sandia researcher Peter Van Blarigan that has been testing physical components of free-piston engines which could be 50% efficient. This is about twice as good as ...

The story of how Honda developed an oval-piston race engine that ultimately failed but still made history along the way. Honda pioneered oval piston technology in the 1970s for four-stroke racing ...

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, ...

Everyone generally knows about piston and rotary engines, with many a flamewar having been waged over the pros and cons of each design. The “correct” answer is thus to combine both into a single ...