An engine cooling system is provided, which includes a water jacket through which coolant flows, a heat exchanger that cools the coolant, a bypass passage that bypasses the heat exchanger and recirculates the coolant to the water jacket, a first radiator passage that recirculates the coolant to the water jacket via the heat exchanger, a flow control device installed at a location where a coolant passage branches into the bypass passage and the first radiator passage, a second radiator passage that bypasses the flow control device and is connected to the first radiator passage, and a thermally-actuated valve installed in the second radiator passage. The flow control device performs a water flow control to adjust a coolant amount flowing into the water jacket by adjusting a coolant amount flowing through the bypass passage. The coolant flows into the first radiator passage through the second radiator passage, when the valve opens.

A cylinder head includes: an exhaust port configured to lead out exhaust gas from combustion chamber; an intake port configured to introduce fresh air into the combustion chamber; and an EGR gas passage in which EGR gas flows, wherein exhaust outlets of the exhaust port and an EGR gas inlet of the second EGR pipe are located on a first side of the cylinder head and, and a fresh air inlet communicated to the intake port and an EGR gas outlet of the EGR gas passage are located on a second side which is opposite from the first side.

A cylinder block assembly may include a cylinder block, a cylinder body disposed in the cylinder block, with a plurality of cylinder bores formed in the cylinder body, a fluid jacket, which is formed between an inner circumferential surface of the cylinder block and an outer circumferential surface of the cylinder body, and through which coolant flows, and a block insert disposed in the water jacket and configured to guide a flow of coolant, wherein the cylinder block may include a second block coolant outlet, which is formed at a second side in a surface of an exhaust side of the cylinder block, and through which the coolant in the water jacket is discharged, and wherein the exhaust side may include a side at which combustion gas is exhausted out of the cylinder body.

A first coolant flow passage is provided to extend in a longitudinal direction of a cylinder head. In at least one of cross sections perpendicular to the longitudinal direction, the first coolant flow passage is located between a flat plane including central axes of a plurality of combustion chambers and parallel to the longitudinal direction and a central line plane including central lines of a plurality of intake ports. In at least one of cross sections perpendicular to the longitudinal direction, at least a portion of a second coolant flow passage is located between the combustion chamber and the first coolant flow passage. A coolant at a temperature lower than that of a coolant flowing in the second coolant flow passage flows in the first coolant flow passage.

Provided is an engine with a starter valve arranged in a compact space and with a cylinder head having a cooling water passage and a starter valve feeding compressed air to a combustion chamber. The starter valve is arranged parallel in the axial direction to a cylinder while fitted into a sleeve, and a portion of the cooling water passage is formed by the outer surface of the sleeve fitted into a starter valve insertion hole formed in the cylinder head. A starting air passage orthogonal to the axial direction of the starter valve insertion hole is formed in the cylinder head, and a portion of the wall surface of the starting air passage is formed by the end surface on one side of the sleeve.

Oil distribution blocks and oil distribution systems equipped therewith. Such an oil distribution block includes a rigid block body configured to be secured to a cylinder head of an engine, an oil inlet, and an oil outlet. The oil inlet is configured to be releasably coupled to a first oil distribution line or a fitting therebetween, receive a flow of oil therefrom, and route the oil to an inlet of a cooling passage of the cylinder head. The oil outlet is configured to be releasably coupled to a second oil distribution line or a fitting therebetween, receive a flow of oil from an outlet of the cooling passage of the cylinder head, and route the oil to the second oil distribution line. The oil inlet and the oil outlet are configured to threadably couple with the first and second oil distribution lines, respectively, or the fittings therebetween.

An internal combustion engine includes a plurality of cylinders, each of which two intake valves and two exhaust valves, respectively arranged in a valve mount of a cylinder head of the internal combustion engine as well as a coolant distributing chamber and a coolant accumulating chamber being associated to. For each cylinder two coolant ducts are formed in the cylinder head and each is fluidly connected to the corresponding coolant distributing chamber and the corresponding coolant accumulating chamber. A first one of the coolant ducts on a first side extends about a first one of the intake valves and on a second side opposite the first side about a first one of the exhaust valves, and a second one of the coolant ducts extends on the first side about a second one of the intake valves and on the second side about a second one of the exhaust valves.

An internal combustion engine includes: an engine body; an exhaust pipe fastened to the engine body; an engine body cooling water passage provided in the engine body and having a cooling water injection port and a cooling water discharge port; an exhaust pipe cooling water passage provided in the exhaust pipe; a supply passage that connects the engine body cooling water passage with the exhaust pipe cooling water passage such that cooling water flows from the engine body cooling water passage to the exhaust pipe cooling water passage through the supply passage; and a return passage that connects the engine body cooling water passage with the exhaust pipe cooling water passage such that the cooling water flows from the exhaust pipe cooling water passage to the engine body cooling water passage through the return passage.

A first coolant flow passage (31, 32) is provided to extend in a longitudinal direction of a cylinder head (101). In at least one of cross sections perpendicular to the longitudinal direction, the first coolant flow passage (31, 32) is located between a flat plane (S1) including central axes of a plurality of combustion chambers (4) and parallel to the longitudinal direction and a central line plane (S2) including central lines of a plurality of intake ports (2). In at least one of cross sections perpendicular to the longitudinal direction, at least a portion (20c) of a second coolant flow passage is located between a cylinder block mating surface (la) of the cylinder head (101) and the intake port central line plane (S2). A coolant at a temperature lower than that of a coolant flowing in the second coolant flow passage (20c) flows in the first coolant flow passage (31, 32).

A vehicle includes a radiator, a bypass passage, a first valve, a second valve, and a controller. Cooling water is circulated through the radiator independently of a cylinder block and a cylinder head of an engine. The radiator cools the cooling water. The cooling water is circulated through the bypass passage while bypassing the radiator. The first valve switches between an open state in which cooling water is circulated through the cylinder block and a closed state in which cooling water is not circulated through the cylinder block. The second valve receives cooling water circulated through the cylinder head and cooling water circulated through the cylinder block via the first valve. The second valve uses an intermediate opening to adjust a flow rate of cooling water circulated through the radiator and the bypass passage. The controller controls opening and closing of the first valve and the opening of the second valve.