Engine with intake ported cylinders and porous port liners for oil control

摘要

An engine having piston-controlled cylinder air intake ports into which lubricating oil may be carried during engine operation is fitted with porous liners in the cylinder intake ports which receive the lubricating oil to prevent its being carried by the inlet air into the engine combustion chamber and exhaust system. Collection and return passages are provided to receive oil drained from the porous liners and return it to the engine crankcase and oil sump. A slight flow of pressurized air from the engine air chamber aids the draining and return passage of oil from the porous liners to the crankcase.