Abstract: In an internal combustion engine a piston and a cylinder head defining a cylinder with a blind end thereatop are formed in a conical configuration. The piston compresses charges of an air/fuel mixture in the blind end of the cylinder, whereupon ignition of the fuel is initiated. Combustion of the fuel proceeds first from the region of ignition in the blind end of the cylinder and then along the interstitial space between the diverging conical walls of the cylinder head and piston. The expanding products of combustion squeeze the piston from the top and the sides, thereby transferring power smoothly and directly to the piston. The progress of combustion spreads equally both downwardly and radially outwardly from the axis of the piston, thereby providing an efficient transfer of power with a high fuel economy.