Methods and systems are provided for an internal combustion engine having an oil circuit. In one example, a system may include a rising oil line from a block to a cylinder head of an engine; a main oil line in the head; and an oil siphon system including a reservoir positioned between, and having at least one portion at a lower elevation than both, a section the rising line and a section of the main oil line so that oil flows into, and remains in, the reservoir when the engine is shut-off. In this way, the design of the oil circuit may be used to improve oil supply to engine components while minimizing delays in oil supply during engine startup.

To improve the oil separation performance in an oil separation device for an internal combustion engine. The oil separation device (10) comprises a gas liquid separation passage (56) internally defined by a lower wall, an upper wall and a pair of side walls, and extending in a horizontal direction, a gas inlet (54) and a gas outlet (63) provided on either end of the gas liquid separation passage, a plurality of lower partition walls (56H) projecting upward from the lower wall, and a plurality of upper partition walls (56J) projecting downward from the upper wall. The lower partition walls and the upper partition wall are tilted with respective the length wise direction in plan view so as to define a spiral passage. The lower wall is inclined with respect to a horizontal plane such that an upstream part of the lower wall is lower than a downstream part of the lower wall with respect to a direction of the swirl flow.

A crankcase oil catcher, the crankcase oil catcher comprising one or more surfaces configured to catch dispersed oil in a crankcase and direct the oil along the surfaces of the crankcase oil catcher away from a crankcase casing wall and towards a crank sump.

This oil return structure is provided with a flow passage body configured to return oil into an engine body which communicates with an oil storage section of the engine, the oil having been separated from a blow-by gas by an oil separation means. The upstream end of the flow passage body is connected to the oil separation means, at least a portion of the downstream side of the flow passage body protrudes into the engine body from the inner wall thereof, and an oil discharge opening at tire downstream end of the flow passage body is disposed at a position not immersed in oil within the oil storage section.

Provided is an internal combustion engine having an oil circulating structure wherein oil used to lubricate valve operating members in the cylinder head drops onto an oil pan, and the oil accumulated therein is drawn up to the cylinder head again. Each on corners of the squire bottom face inside the cylinder head of the internal combustion engine, an oil dropping hole is provided to allow the oil used to lubricate valve operating members to flow thereinto. Also provided is an oil channel communicating with one or more of the oil dropping hole at the bottom thereof to guide the oil toward the driving gear transmitting the driving force of the engine.

Provided is an internal combustion engine having an oil circulating structure wherein oil used to lubricate valve operating members in the cylinder head drops onto an oil pan, and the oil accumulated therein is drawn up to the cylinder head again. Each on corners of the squire bottom face inside the cylinder head of the internal combustion engine, an oil dropping hole is provided to allow the oil used to lubricate valve operating members to flow thereinto. Also provided is an oil channel communicating with one or more of the oil dropping hole at the bottom thereof to guide the oil toward the driving gear transmitting the driving force of the engine.

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 includes a crankcase with a plurality of piston-cylinder arrangements and a valve head positioned above the crankcase at least in part containing a valve train. The internal combustion engine further includes a head cover coupled to the valve head and having a blowby outlet and a baffle positioned between the head cover and the crankcase and defining an oil passage internal to the baffle. Engine oil circulates through the oil passage of the baffle to transfer heat to blowby gas flowing from one or more of the plurality of piston-cylinder arrangements before exiting the valve head through the blowby outlet in the head cover.

An internal combustion engine includes an engine lubrication fluid storage system with a primary storage volume and a secondary storage volume that is separate from the primary storage volume. The secondary storage volume is linked to the primary storage volume with a fluid flow path that is throttled so that lubrication fluid is stored in the secondary storage volume during engine operation, and drains from the secondary storage volume to the primary storage volume when the engine is not running.

A head cover structure (45) for an internal combustion engine (1) comprises a head cover (4) connected to a cylinder head (3), and an auxiliary cover (44) connected to the head cover and defining a gas-liquid separation passage (74) jointly with the head cover, the gas-liquid separation passage being communicated with a crankcase chamber (11) of the internal combustion engine, and configured to separate lubricating oil from a crankcase gas drawn from the crankcase chamber, wherein the auxiliary cover is integrally formed with an intake pipe (49) internally defining a part of an intake passage (20) of the internal combustion engine, and the auxiliary cover internally defines a crankcase gas introduction passage (63) communicating the gas-liquid separation passage with an interior of the intake pipe.