Characterization of the wear of piston rings and cylinder liner is an important aspect of large two stroke diesel engine design. Two major wear mechanisms exist; corrosive wear and mechanical wear. This paper deals with the most aggressive form of the latter, which is known as scuffing. Different material combinations for piston rings and cylinder liners are examined using a block-on-ring test rig. An accelerated wear test run without lubricant is used. Results show that the morphology of cast iron is an important parameter affecting the wear resistance of the material. It is also demonstrated that ceramic coating on the piston ring decreases the dry wear rate of both piston ring and liner, while the coefficient of friction is increased.