Top piston ring for a large two-stroke turbo-charged compression ignited internal combustion engine

A top piston ring for use in a piston ring pack in a groove in a piston of a large two-stroke turbo charged uniflow-scavenged internal combustion engine with crossheads. The top piston ring comprises a ring body with an upper ring face, a lower ring face, an outer ring face, an inner ring face and first- and second engaging end portions at a ring partition. The first engaging end portion comprises a circumferentially extending finger, the second engaging end portion comprises a circumferentially extending recess shaped and sized for sealingly and slidably receiving the finger. The finger is provided with a radially projecting tongue that extends circumferentially over at least a portion of the circumferential extent of the finger. The recess is provided with a groove that extends circumferentially over at least a portion of the circumferential extent of the recess. The tongue and groove are complementary in shape in the radial and axial direction and the groove receives at least a portion of the circumferenti