VARIABLE DISPLACEMENT ENGINE

A combustion engine comprises a main combustion cylinder configured to enable a piston to move therein; a main valve configured to move in the main combustion cylinder; an upper non-combustion chamber operatively adjacent to the main combustion cylinder; an upper intake valve configured to move in the upper non-combustion chamber and to communicate with an intake manifold; and an upper exhaust valve configured to move in the upper non-combustion chamber and to communicate with an exhaust manifold.