Abstract: Combustion engine having no connecting rods or crankshaft, whose cylinders are disposed radially. In this engine, the axes of the cylinders are situated in a plane perpendicular to the drive shaft, the alternating movement of the pistons being transmitted by rollers fixed to the said pistons, which rollers roll on a cam fixed to the engine. The movement of the pistons is transmitted via at least three cams, a central cam rotating in one direction and two lateral cams rotating at the same speed but in the opposite direction, the three cams being positioned in a manner such that the apexes of the bosses which they possess are situated in the plane of the axis of the drive shaft at top dead center.