A machine having one or more cylinders, each cylinder having an inner surface configured to engage a circumferential surface of a piston ring of a piston thereby defining a contact zone between the inner surface of the cylinder and the circumferential surface of the piston ring, the inner surface having at least one recess indented into the inner surface, wherein the ratio of the dimension of the recess in the direction of travel of the piston to the dimension of the contact zone in the direction of travel of the piston is in the range of approximately 1:5 to 3:5.

A machine having one or more cylinders, each cylinder having an inner surface configured to engage a circumferential surface of a piston ring of a piston thereby defining a contact zone between the inner surface of the cylinder and the circumferential surface of the piston ring, the inner surface having at least one recess indented into the inner surface, wherein the ratio of the dimension of the recess in the direction of travel of the piston to the dimension of the contact zone in the direction of travel of the piston is in the range of approximately 1:5 to 3:5.

A carbon scraper, a method of manufacturing a system with a carbon scraper, and method of scraping carbon from a piston of an internal combustion engine are provided. The carbon escaper includes an outer annular metallic shell portion having an annular recess therein. The annular scraper also includes an inlaid thermal barrier coating portion positioned within the annular recess of the outer annular metallic shell portion such that the inlaid thermal barrier coating portion is concentric with an outer annular metallic shell portion.

A combined oil filter and restrictor assembly is disclosed having an oil flow restrictor interposed between first and second filters so that, irrespective of the direction of oil flow through the restrictor, debris cannot enter a small diameter bore 32 in a body of the restrictor thereby reducing the likelihood of restrictor blockage. The combined oil filter and restrictor assembly includes a metal threaded member that enables the combined oil filter and restrictor assembly to be easily and quickly assembled to or removed from a component such as a cylinder head of a variable displacement engine. The combined oil filter and restrictor assembly can be used to provide a restricted flow of oil from oil supply passages to signal oil passages used for controlling the operation of deactivatable hydraulic lash adjusters so as to purge the signal oil passages when the deactivatable hydraulic lash adjusters are not deactivated.

A combined oil filter and restrictor assembly is disclosed having an oil flow restrictor interposed between first and second filters so that, irrespective of the direction of oil flow through the restrictor, debris cannot enter a small diameter bore 32 in a body of the restrictor thereby reducing the likelihood of restrictor blockage. The combined oil filter and restrictor assembly includes a metal threaded member that enables the combined oil filter and restrictor assembly to be easily and quickly assembled to or removed from a component such as a cylinder head of a variable displacement engine. The combined oil filter and restrictor assembly can be used to provide a restricted flow of oil from oil supply passages to signal oil passages used for controlling the operation of deactivatable hydraulic lash adjusters so as to purge the signal oil passages when the deactivatable hydraulic lash adjusters are not deactivated.

Disclosed herein are a two-stroke internal combustion engine, a lubrication device, and a two-stroke combustion engine cylinder comprising the lubrication device. In the engine, the lubrication device defines jointly with a sliding portion of a piston and a portion of the cylinder, a lubrication fluid retention region, wherein the lubrication device provides lubrication fluid for the lubrication fluid retention region.

Disclosed herein are a two-stroke internal combustion engine, a lubrication device, and a two-stroke combustion engine cylinder comprising the lubrication device. In the engine, the lubrication device defines jointly with a sliding portion of a piston and a portion of the cylinder, a lubrication fluid retention region, wherein the lubrication device provides lubrication fluid for the lubrication fluid retention region.