Abstract: A magnetic engine is disclosed which includes a first permanent magnet (10) and a second element (12) which may also be in the form of a permanent magnet or a member made from magnetically attractable material (201). An output (51, 250) is provided for providing output rotary motion. A flux altering means in the form of circular valve discs (16) are provided for movement into and out of registry with the magnet (10) for relocating magnetic flux produced by the magnet (10) away from the element (12, 201) so as to change the magnetic attraction or repulsion experienced by the element (12, 201) between movement towards the valve (10) and away from the valve (10) to thereby produce a net power input which can be supplied to the output (51, 250) to provide output from the engine.