Manson engine

[1] Manson engines can be started in either direction (clockwise or anti-clockwise).

The front part acts as a displacer and the back part acts as a work piston (the displacer and the work piston move as a single component).

The engines are built mainly as desk toys, physics demonstrations, and novelties.

[3][5][8][2] The displacer and work piston of the Manson engine have zero phase angle.

[4] The valves and gas paths are considered by some to be complicated to manufacture, so various variants exist with improved, modified, or simplified valves and gas paths.