An engine assembly is provided. The engine assembly comprises a first housing defining a first oil gallery, a second housing defining a second oil gallery, and an alignment dowel configured to be received within the first and second housings to provide an alignment feature for locating first and second housings of an engine assembly relative to one another, wherein the alignment dowel comprises a groove formed in an outer surface of the dowel configured to receive oil from the first oil gallery, and wherein the dowel is configured to provide a flow channel for the received oil to flow to the second oil gallery. An alignment dowel for use in the engine assembly is also provided.

An engine housing component is provided, the housing component defining two or more drain channels configured to receive oil separated from a crankcase ventilation system and to drain said oil through the housing component, wherein the engine housing component comprises two or more drain features, each of the drain features corresponding to one of the drain channels, wherein each of the drain features is configured to allow an oil drain pipe to be coupled to the drain feature such that the oil drain pipe is in fluid communication with the corresponding drain channel, wherein a first drain feature differs from the or each of the other drain features, such that a particular oil drain pipe configured to couple to the first drain feature is not couplable to the other drain features. An engine housing assembly and kit of oil drain pipes is also provided.

The invention describes an internal combustion engine having at least one crankcase, at least one cylinder head, at least one cylinder head cover, at least one oil separator and at least one oil pan for collecting returning oil as well as having at least one oil return channel that connects the oil separator and the oil pan.

First and second oil chambers arranged in a cylinder arrangement direction with a partition wall interposed therebetween are formed in a cylinder block. A cylinder head includes first and second communication passages respectively connected to the first and second oil chambers. The communication passages are configured so that a resistance generated when gas is caused to flow from the first oil chamber to a space above the head through the first communication passage is smaller than a resistance generated when gas is caused to flow from the second oil chamber to the space above the head through the second communication passage. The cylinder block includes an oil passage connected to both the oil chambers. The partition wall includes a connection hole for allowing the first and second oil chambers to communicate with each other.

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.

An engine block with an oil path switching arrangement is proposed. The engine block includes an oil sump, an oil pump, a clean oil riser and a switching valve. The switching valve has in each case connections for the oil sump, the oil pump and the clean oil riser. The switching valve is switchable to open and close the connections, including a first position in which a connection between the clean oil riser and the oil sump is established, thereby avoiding discharge of oil in the clean oil riser through an oil filter receptacle during an oil change.

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 cylinder crankcase for an internal combustion engine includes at least one riser duct. The cylinder crankcase comprises at least one additional riser duct, which is configured to exchange oil between the main oil gallery and the cylinder head. The cylinder crankcase also comprises a connecting duct, via which the at least one riser duct and the at least one additional riser duct are connected in an oil-conducting fashion.

An oil pan in an engine assembly comprises a housing including a bottom wall and a sidewall and an oil drain tube. The oil drain tube includes a tubing wall and a portion of the sidewall and is integrally formed with the housing.

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.