A cylinder head cleaning method capable of cleaning a cylinder head with an enhanced foreign matter removing rate. The method is used to clean a cylinder head (1) having therein a water jacket (15) including a narrow space portion (Z) having a narrow flow path and a large space (Y) having a flow path wider than the narrow space portion (Z), and the cylinder head (1) further having holes (12A-12R, 13, 14, 16A-16C) communicating with the water jacket (15). Cleaning nozzles (28A, 28C) are inserted into the water jacket (15) from the holes (16A, 16C) selected from the holes (12A-12R, 13, 14, 16A-16C), clearing liquid is ejected from the cleaning nozzles (28A, 28C) toward the narrow space portion (Z), and the cleaning liquid flowing from the narrow space portion (Z) to the large space (Y) is discharged to the outside of the cylinder head (1) from the hole (16B) communicating with the space (Y).

A cylinder head includes: a cylinder head body that includes a lower deck, an upper deck defining a first cooling water space together with the lower deck, and valve hole-forming walls; a rocker housing that includes a rocker-side wall formed integrally with the cylinder head body; an expansion wall portion that expands from the cylinder head body and defines a second cooling water space communicating with the first cooling water space and extending up to a position over the upper deck; and an EGR passage-forming portion that is provided in the second cooling water space.

A cylinder head includes: a cylinder head body that includes a lower deck, an upper deck defining a first cooling water space together with the lower deck, and valve hole-forming walls; a rocker housing that includes a rocker-side wall formed integrally with the cylinder head body; an expansion wall portion that expands from the cylinder head body and defines a second cooling water space communicating with the first cooling water space and extending up to a position over the upper deck; and an EGR passage-forming portion that is provided in the second cooling water space.

The present invention is related to a method for manufacturing a water cooling system (20) inside a casted cylinder head (10), the water cooling system (20) comprising an upper water jacket (21) and a lower water jacket (22) and wherein a transition channel (23) is located between the upper water jacket (21) and the lower water jacket (22). Further, the invention is related to a water cooling system (20) inside a casted cylinder head (10), comprising an upper water jacket (21) and a lower water jacket (22) wherein the upper water jacket (21) and the lower water jacket (22) are fluidly connected by at least one transition channel (23).

An oil passage which supplies hydraulic oil to a cylinder deactivation apparatus (CDA) that operates by hydraulic pressure may include a high pressure passage, a low pressure passage, and an orifice, all of which may be integrally formed in either a cylinder head or a cam carrier. The high pressure passage may be connected to an oil supply apparatus and receive oil therefrom. The low pressure passage may be coupled to the high pressure passage and receive pressurized oil therefrom and form a low pressure relatively lower than a pressure in the high pressure passage. The low pressure passage may be connected to supply a hydraulic pressure to the CDA. The orifice may couple the high pressure passage to the low pressure passage, communicate the high pressure passage and the low pressure passage and may be formed to supply oil from the high pressure passage to the low pressure passage.

An oil passage which supplies hydraulic oil to a cylinder deactivation apparatus (CDA) that operates by hydraulic pressure may include a high pressure passage, a low pressure passage, and an orifice, all of which may be integrally formed in either a cylinder head or a cam carrier. The high pressure passage may be connected to an oil supply apparatus and receive oil therefrom. The low pressure passage may be coupled to the high pressure passage and receive pressurized oil therefrom and form a low pressure relatively lower than a pressure in the high pressure passage. The low pressure passage may be connected to supply a hydraulic pressure to the CDA. The orifice may couple the high pressure passage to the low pressure passage, communicate the high pressure passage and the low pressure passage and may be formed to supply oil from the high pressure passage to the low pressure passage.

There is provided an engine water-cooling device that can increase warming-up efficiency of an engine. The engine water-cooling device includes a thermostat housing that houses a thermostat. The thermostat housing is mounted to a front wall of a cylinder head in one side portion in a width direction of the cylinder head. A cooling water pump is mounted to a front wall of a cylinder block in a central portion in a width direction of the cylinder block. A bypass passage includes an intra-head bypass passage in the cylinder head, and the intra-head bypass passage includes a width-direction passage portion extending from a position behind the thermostat housing to a position behind and above the cooling water pump.

The present invention relates to a liquid-cooled internal combustion engine comprising an engine block, which includes a plurality of cylinders, and cylinder heads closing the cylinders, wherein each cylinder is surrounded by a respective cooling liner and each cylinder head has provided therein at least one separate cooling chamber connected to the cooling liner of the associated cylinder via at least one transition channel, wherein the transition channels of at least two cylinders are interconnected via a pressure compensation chamber.

An engine is provided with a cylinder head having a bridge region surrounded by an exhaust face, an exhaust passage intersecting the exhaust face, and an exhaust gas recirculation (EGR) passage fluidly coupled to the exhaust passage and intersecting the exhaust face. The head defines an upper cooling jacket having a cavity or fluid passage extending from the jacket towards a head deck face and to a closed end wall within the bridge region. The cylinder head is cooled by directing coolant from a lower jacket to an upper jacket via a drill passage adjacent to an exhaust face of the head, diverting the coolant exiting the drill passage into the fluid passage or cavity along a rib. Coolant is then directed from the fluid passage into an EGR cooling passage formed by the upper jacket adjacent to the exhaust face and about the EGR passage.

An engine is provided with a cylinder head having a bridge region surrounded by an exhaust face, an exhaust passage intersecting the exhaust face, and an exhaust gas recirculation (EGR) passage fluidly coupled to the exhaust passage and intersecting the exhaust face. The head defines an upper cooling jacket having a cavity or fluid passage extending from the jacket towards a head deck face and to a closed end wall within the bridge region. The cylinder head is cooled by directing coolant from a lower jacket to an upper jacket via a drill passage adjacent to an exhaust face of the head, diverting the coolant exiting the drill passage into the fluid passage or cavity along a rib. Coolant is then directed from the fluid passage into an EGR cooling passage formed by the upper jacket adjacent to the exhaust face and about the EGR passage.