An internal combustion engine, in particular, a diesel internal combustion engine, including a cylinder crankcase (1), at least one oil return collection groove (2), at least one oil drain (3), in which depressurized oil (4) discharges in the direction of the oil pan, following gravity, and at least one cylinder (5) is provided.

An internal combustion engine, in particular, a diesel internal combustion engine, including a cylinder crankcase (1), at least one oil return collection groove (2), at least one oil drain (3), in which depressurized oil (4) discharges in the direction of the oil pan, following gravity, and at least one cylinder (5) is provided.

An outboard motor with improved maintainability and attachable to a hull of a marine vessel includes an internal combustion engine and a cowl to cover the internal combustion engine. The internal combustion engine includes an oil filler to feed oil thereto and an oil filter to filter the oil. In a case that a direction perpendicular or substantially perpendicular to a bottom of the hull is a vertical direction, the cowl is separable into a top cowl to cover an upper portion of the internal combustion engine and a side cowl to cover a side portion of the internal combustion engine. At least a portion of the oil filler or at least a portion of the oil filter is located above a separating line which is a boundary between the top cowl and the side cowl.

An outboard motor with improved maintainability and attachable to a hull of a marine vessel includes an internal combustion engine and a cowl to cover the internal combustion engine. The internal combustion engine includes an oil filler to feed oil thereto and an oil filter to filter the oil. In a case that a direction perpendicular or substantially perpendicular to a bottom of the hull is a vertical direction, the cowl is separable into a top cowl to cover an upper portion of the internal combustion engine and a side cowl to cover a side portion of the internal combustion engine. At least a portion of the oil filler or at least a portion of the oil filter is located above a separating line which is a boundary between the top cowl and the side cowl.

A vehicular internal combustion engine is equipped with a supercharger, a drain pipe for draining lubricating oil in the supercharger, a cylinder block including a first oil passage, and a PCV separator including a second oil passage connected to an outlet of the drain pipe and an inlet of the first oil passage.

A vehicular internal combustion engine is equipped with a supercharger, a drain pipe for draining lubricating oil in the supercharger, a cylinder block including a first oil passage, and a PCV separator including a second oil passage connected to an outlet of the drain pipe and an inlet of the first oil passage.

A quick return oil cylinder liner is disclosed. The cylinder liner includes an elongated cylindrical body having an outer surface and an inner surface defining a liner central axis extending between a first liner axial end and a second liner axial end. The inner surface is configured to form a combustion chamber with a piston and an engine housing. A quick oil return part is arranged on the inner surface of the cylinder liner corresponding to a non-skirt part of the piston. The oil return part is positioned below a position of the inner surface corresponding to an oil blade of an oil ring of the piston when the piston is positioned at a bottom dead center position. The oil return part extends to the second linear axial end and forms at opening at the second liner axial end.

A quick return oil cylinder liner is disclosed. The cylinder liner includes an elongated cylindrical body having an outer surface and an inner surface defining a liner central axis extending between a first liner axial end and a second liner axial end. The inner surface is configured to form a combustion chamber with a piston and an engine housing. A quick oil return part is arranged on the inner surface of the cylinder liner corresponding to a non-skirt part of the piston. The oil return part is positioned below a position of the inner surface corresponding to an oil blade of an oil ring of the piston when the piston is positioned at a bottom dead center position. The oil return part extends to the second linear axial end and forms at opening at the second liner axial end.

An engine assembly is provided. The engine assembly comprises an oil system comprising: a first oil pump configured to supply oil at a first pressure to one or more first components of the engine assembly; and a second oil pump configured to supply oil at a second pressure to one or more second components of the engine assembly, the second pressure being higher than the first pressure; wherein the second oil pump is provided adjacent to a valve train of the engine assembly.

An engine assembly is provided. The engine assembly comprises an oil system comprising: a first oil pump configured to supply oil at a first pressure to one or more first components of the engine assembly; and a second oil pump configured to supply oil at a second pressure to one or more second components of the engine assembly, the second pressure being higher than the first pressure; wherein the second oil pump is provided adjacent to a valve train of the engine assembly.