In an in-line four-cylinder internal combustion engine, exhaust ports (2b, 2c) of cylinders #2 and #3 merge together inside a cylinder head and become open as one flat collective exhaust port (2bc). An exhaust manifold (5) includes separate individual exhaust pipes (6, 7) for cylinders #1 and #4 and a collective exhaust pipe (8) for cylinders #2 and #4. Tip ends of these three exhaust pipes are connected to a catalytic converter (11). An equivalent diameter of the collective exhaust port (2bc) is larger than equivalent diameters of the exhaust ports (2a, 2d) before merging. A short diameter of the collective exhaust port (2bc) is smaller than or equal to the equivalent diameters of the exhaust ports (2b, 2c).

A cylinder head containing an exhaust system manifold for an engine includes screw holes formed through a fastening face of the cylinder head and an exhaust pipe, and outlet cooling channels that are provided adjacent to an outlet of a confluence of the manifold, and are disposed between the screw holes and the outlet. Coolant flows through the outlet cooling channels.

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.

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 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.

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 plurality of exhaust ports provided corresponding to a plurality of cylinders, and configured to converge outlets of the exhaust ports inside the cylinder head, at least one of the exhaust ports not being provided with a water jacket there above, and a pair of oil passages arranged so as to sandwich the at least one of the exhaust ports above which the water jacket is not provided. An inclined surface provided on an upper surface of the cylinder head and positioned between the pair of oil passages, the inclined surface being inclined from one oil passage, of the pair of oil passages, toward the other oil passage.

A coolant control system of a vehicle includes a pump control module and a coolant valve control module. The pump control module selectively activates a coolant pump. The coolant pump pumps coolant into coolant channels formed in an integrated exhaust manifold (IEM) of an engine. The coolant valve control module selectively actuates a coolant valve that controls coolant flow from the coolant channels formed in the IEM to a transmission heat exchanger based on a first temperature of a transmission and a second temperature of coolant within the integrated exhaust manifold of the engine.

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.