A method for operating an internal combustion engine is provided. The method includes during a first operating condition, operating two primary cylinders and two secondary cylinders to perform combustion, the two primary and secondary cylinders arranged in an inline configuration, the two primary cylinder adjacent to one another, the two secondary cylinders adjacent to one another, and the secondary cylinders positioned 175°-185° out of phase relative to the two primary cylinders and during a second operating condition, selectively deactivating the two secondary cylinders to perform combustion in only the two primary cylinders.

A lower water jacket of a cylinder head includes a lower/upper exhaust collecting portion cooling portion configured between a lower exhaust collecting portion and an upper exhaust collecting portion by bypassing a lower exhaust collecting portion cooling portion. Besides, cooling water flowing through the lower/upper exhaust collecting portion cooling portion is merely cooling water of the lower water jacket, and cooling water of an upper water jacket does not flow through the lower/upper exhaust collecting portion cooling portion. Therefore, in the lower/upper exhaust collecting portion cooling portion, interference may not occur in cooling water of the two water jackets to restrain smooth flowing, and cooling effects of an area sandwiched by the lower exhaust collecting portion and the upper exhaust collecting portion are further improved.

A lower water jacket of a cylinder head includes a lower/upper exhaust collecting portion cooling portion configured between a lower exhaust collecting portion and an upper exhaust collecting portion by bypassing a lower exhaust collecting portion cooling portion. Besides, cooling water flowing through the lower/upper exhaust collecting portion cooling portion is merely cooling water of the lower water jacket, and cooling water of an upper water jacket does not flow through the lower/upper exhaust collecting portion cooling portion. Therefore, in the lower/upper exhaust collecting portion cooling portion, interference may not occur in cooling water of the two water jackets to restrain smooth flowing, and cooling effects of an area sandwiched by the lower exhaust collecting portion and the upper exhaust collecting portion are further improved.

Systems and methods are provided for an exhaust gas recirculation (EGR) system in a vehicle. In one example, a system may include a cylinder head including an integrated exhaust manifold (IEM), an EGR cartridge including an EGR valve positioned in the cylinder head at a central collector region of the IEM, and a water jacket formed within the cylinder head, the water jacket including at least one cooling passage that extends around a circumference of the EGR cartridge. In this way, an EGR system is provided that has a reduced volume between an exhaust valve of a cylinder to the EGR valve, reducing packaging space and complexity of the EGR system while increasing engine performance.

A cooling system for an internal combustion engine is provided. The cooling system comprises: a cooling passage provided within an engine housing of the engine, the cooling passage configured to carry a bulk flow of coolant to cool the engine housing, wherein the bulk flow of coolant within the cooling passage is driven by convection or a pump; and one or more additional cooling passages provided within the engine housing, each configured to introduce a flow of coolant into the cooling passage; one or more additional cooling passage pumps configured to pump coolant within the additional cooling passages; wherein the engine housing comprises one or more high temperature regions, which are at a higher temperature than one or more low temperature regions of the engine housing; and wherein the additional cooling passages are configured to direct the introduced coolant towards the one or more high temperature regions.

The present invention is configured such that: a cylinder block includes an introducing portion provided at a first side of a cylinder row, cooling liquid being introduced through the introducing portion to a water jacket, a restrictor portion provided in a vicinity of the introducing portion and configured to restrict the cooling liquid, introduced through the introducing portion, from flowing to an intake-side portion of the water jacket, and a discharging portion provided at a middle portion of the cylinder row at an intake side, the cooling liquid being discharged from the water jacket through the discharging portion; and an exhaust-side portion of the water jacket is formed such that a passage cross-sectional area of a cylinder axis direction upper side of the exhaust-side portion is larger than the passage cross-sectional area of a cylinder axis direction lower side of the exhaust-side portion.

The present invention is configured such that: a cylinder block includes an introducing portion provided at a first side of a cylinder row, cooling liquid being introduced through the introducing portion to a water jacket, a restrictor portion provided in a vicinity of the introducing portion and configured to restrict the cooling liquid, introduced through the introducing portion, from flowing to an intake-side portion of the water jacket, and a discharging portion provided at a middle portion of the cylinder row at an intake side, the cooling liquid being discharged from the water jacket through the discharging portion; and an exhaust-side portion of the water jacket is formed such that a passage cross-sectional area of a cylinder axis direction upper side of the exhaust-side portion is larger than the passage cross-sectional area of a cylinder axis direction lower side of the exhaust-side portion.

A cylinder cooling apparatus for an engine may include a plurality of intake ports disposed in a cylinder head and communicating with a corresponding plurality of cylinders, a water supply line extending inside from a side of the cylinder head and communicating with the intake ports, and a water pump supplying water to the intake ports through the water supply line.

A cylinder cooling apparatus for an engine may include a plurality of intake ports disposed in a cylinder head and communicating with a corresponding plurality of cylinders, a water supply line extending inside from a side of the cylinder head and communicating with the intake ports, and a water pump supplying water to the intake ports through the water supply line.

A cooling structure of an engine includes a cylinder head and a coolant temperature sensor. The cylinder head gas a first water jacket for cooling a combustion chamber and a second water jacket for cooling an exhaust manifold. The cylinder head includes a joining portion where coolants from the first water jacket and the second water jacket join together. The joining portion has a first coolant passage. A second coolant passage is disposed downstream of the joining portion. The temperature sensing portion is disposed in the second coolant passage. A coolant outlet of the second water jacket is defined in the first coolant passage, and is located at a position on the cylinder head cover attachment surface side in the first coolant passage. The temperature sensing portion is located at a position on the cylinder block attachment surface side in the second coolant passage.