One piece piston connected to a connecting rod for high speed four-stroke cycle internal combustion engines

In combination for Diesel engines:

• a one piece piston made of cast iron having a longitudinal axis and having a piston mantle provided in a closed form with a piston bottom and a piston top with a spherical combustion chamber in the central area of said piston top and with peripheral piston ring grooves, said combustion chamber having a constricted opening, said piston also being provided with a piston skirt having two oppositely located flat surfaces located in axially spaced relationship to said piston ring grooves and radially inwardly offset with regard to said piston ring grooves, a hollow piston bolt extending in transverse direction to the longitudinal axis of said piston between said flat surfaces of said piston, said flat surfaces being located parallel to the piston longitudinal axis and extending vertically at least approximately within the plane of two diametrically opposite outer wall portions of said combustion chamber, bearing means arranged within said piston and rotatably supporting piston bolt, and a connecting rod firmly shrunk upon said piston bolt so as to be fixedly connected thereto and having overall reduction in compression height realized therewith.