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 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.

Methods and systems are provided for a 2-port integrated exhaust manifold for an inline-3, inline-6, V-6, and/or V-12 engine. In one example, a system may include an exhaust manifold integrated within a cylinder head of an engine block. The integrated exhaust manifold may include a first set of two runners from a first outer cylinder coupled to a first manifold exhaust port, a second set of two runners of a second outer cylinder coupled to a second manifold exhaust port, and one runner of an inner cylinder coupled to the first manifold exhaust port and another runner of the inner cylinder coupled to the second manifold exhaust port.

Methods, assemblies and apparatuses are for forming a cooling jacket in a cast part of a marine engine, for example in a cylinder head for the marine engine. A cooling jacket core has a longitudinally elongated first portion that forms a first flow path for conveying cooling fluid through the cast part in a first direction and a longitudinally elongated second portion that forms an opposite, second flow path for conveying cooling fluid through the cast part in an opposite, second direction. At least one bridge integrally supports the first and second portions with respect to each other during casting. At least one plug is configured to fit in the cast part where the bridge was located so as to separate the first and second flow paths from each other while sealing the first and second flow paths from an opposite side of the cast part.

An internal combustion engine has a cylinder head having an integrated exhaust manifold having exhaust ducts connected to a secondary air system's distributor block via its supply ducts for supplying ambient air through an inlet as secondary air into the exhaust manifold. Each supply duct having a valve assembly having a closure flap pivotable about a pivot axis at a distance from its the center of mass. The closure flap closing due to the influence of gravity when there is no pressure difference between the exhaust manifold and the secondary air system and opening automatically due to a relative overpressure in the gas pressure on the side of the secondary air system in relation to the gas pressure on the side of the exhaust manifold.

The application relates to internal combustion engines, cylinder heads, exhaust passages, and shapes and configurations of the exhaust passages. The exhaust passage may have cross-sectional shapes formed by two limbs. The cross-sectional shape of the exhaust passage may change as the passage extends. The exhaust passage may also merge with other exhaust passage. The exhaust passage may be part of a cylinder head or an exhaust manifold.

A multi-cylinder engine includes an engine body having first and second cylinder groups, first and second exhaust passage groups each having a plurality of independent exhaust passage parts and a collective exhaust passage part, and an exhaust gas recirculation (EGR) passage. In a plan view in cylinder axis directions, the passage groups are disposed adjacent to each other, and, in the first exhaust passage group, a first independent exhaust part of the plurality of independent exhaust passage parts is connected to the EGR passage and a second independent exhaust passage part is connected to the collective exhaust passage part so as to be directed to a connection of the first independent exhaust passage part to the collective exhaust passage part, and in the second exhaust passage group, an opening of the collective exhaust passage part is offset toward the first exhaust passage group in a lineup direction.

A cylinder head with integrated exhaust manifold includes a cylinder head housing, an exhaust manifold, and first, second and third water jackets. The cylinder head housing has a combustion chamber formed in a bottom surface thereof and an internal receiving space. The exhaust manifold is received in the space of the cylinder head housing and is connected to exhaust ports of the cylinder head housing. The first water jacket is received in the space of the cylinder head housing and disposed adjacent to the combustion chamber. The second water jacket is received in the space of the cylinder head housing and disposed to contact a bottom of the exhaust manifold. The third water jacket is received in the space of the cylinder head housing and disposed to contact a top of the exhaust manifold.

A multi-cylinder engine having an engine body with a cylinder head is provided. The engine includes first and second cylinder groups, each having a plurality of independent exhaust passage parts provided to the cylinder head and connected to cylinders of the first and second cylinder groups, respectively, and first and second collective exhaust passage parts collecting the first and second pluralities of independent exhaust passage parts at a location downstream in an exhaust gas flow direction, and having an opening formed in the side surface part of the cylinder head, first and second exhaust-pipe parts each connected to the openings of the first and second collective exhaust passage parts, respectively, an exhaust gas recirculation (EGR) passage connected at one end to the first exhaust passage group and connected at the other end to an intake passage, and an exhaust gas temperature sensor provided to the first exhaust-pipe part.

An internal combustion engine having an exhaust log structure onto which a plurality of turbochargers is connected, each turbocharger having a turbine connected to the exhaust log structure and having an inlet fluidly connectable to a respective one of the plurality of outlet ports, an exhaust valve disposed at a turbine outlet such that the flow of exhaust gas out of the turbine is fluidly blocked, and an actuator associated with the exhaust valve and operating to move the exhaust valve from a closed position to an open position and vice versa. An electronic controller provides a command to the actuator to move the exhaust valve between the open and closed positions and is programmed to selectively open two one or more exhaust valves based on an operating condition of the engine.