Internal combustion engine with automatic compression release

Abstract From the Canadian patent

An internal combustion engine is illustrated having an engine block, a cylinder located in the engine block, and a cylinder head defining an end wall of the cylinder. A piston is housed in the cylinder and defines with the cylinder and the cylinder head a combustion space adapted to receive a mixture of fuel and air therein. The piston is reciprocably movable toward the cylinder head to compress a fuel mixture in the cylinder and movable away from the cylinder head the piston engaging one side of the cylinder as the piston moves toward the cylinder and engaging an opposite side of the cylinder as the piston moves away from the cylinder head. The piston includes an annular groove, and the …