A multi-cylinder engine having an engine body with a cylinder head, and mounted on a vehicle is provided. The engine includes first and second cylinder groups each provided to the engine body and comprised of first and second pluralities of cylinders, first and second exhaust passage groups each having first and second pluralities of independent exhaust passage parts provided to the cylinder head and connected to the first and second cylinder groups, respectively, and first and second collective exhaust passage parts provided to the cylinder head and collecting the first and second pluralities of independent passage parts downstream in an exhaust gas flow direction, and a cooling medium passage provided in the cylinder head, through which a cooling medium flows, and having an intermediate passage part provided between the first collective exhaust passage part and the second collective exhaust passage part.

Methods and systems are provided for thermally insulating an integrated exhaust manifold for a cylinder head of an applied-ignition, liquid-cooled internal combustion engine. In one example, a method may include regional insulation at a collection point where individual exhaust lines and/or partial exhaust lines merge to form an overall exhaust line within the cylinder head. The regional insulation may be formed integrally with a seal and coupled to an outlet flange of the cylinder head and may include a series of tongue-like projections that extend from the cylinder head outlet flange toward the cylinder exhaust lines.

Systems and methods for operating a turbocharged engine are described. In one example, a system comprises a cylinder head having a first and second exhaust duct separately coupled to first and second groups of cylinders, each of the first and second exhaust ducts leading to an exhaust driven turbine mounted inside the cylinder head on a bearing, the bearing located within a bearing housing supported by the cylinder head. In this way, exhaust pulses remain separate up to the turbine mounted inside the cylinder head.

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 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.

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).

An internal combustion engine includes: a cylinder block including multiple cylinders; a cylinder head; and a turbocharger including an inlet port connected to an exhaust outlet of the cylinder head. The inlet port includes a first wall portion located between one cylinder out of the two outermost cylinders and the central axis of the inlet port in the cylinder array direction, and a second wall portion located on the opposite side of the central axis of the inlet port from the first wall portion. The first wall portion includes a thick-walled portion that is greater in thickness than the second wall portion, and a thin-walled portion that is smaller in thickness than the thick-walled portion and is located upstream of the thick-walled portion in the direction of exhaust gas flow.

A cylinder head casting for a three cylinder engine having a dedicated exhaust gas recirculation cylinder and two non-dedicated cylinders, includes three combustion chamber upper wall portions. First and second exhaust ports/runners extend from two of the three combustion chamber upper wall portions, respectively, for the non-dedicated cylinders and are paired together prior to a first common breakout at an exhaust flange in a side face of the cylinder head. A third exhaust port/runner extends from the other of the three combustion chamber upper wall portions corresponding to the dedicated EGR cylinder remains separated from the first and second exhaust port runners until a separate second breakout at the exhaust flange.

An internal combustion engine for an outboard motor comprises a cylinder block having first and second banks of cylinders that extend transversely with respect to each other in a V-shape so as to define a valley there between. An exhaust manifold conveys exhaust gas from the internal combustion engine and is at least partially disposed in the valley. A supporting mechanism supports the exhaust conduit with respect to the internal combustion engine. The supporting mechanism is configured to allow the exhaust conduit to move with respect to the internal combustion engine in 360 degrees in a plane defined by the lateral and transverse axes, and laterally towards and away from the internal combustion engine, thereby facilitating assembly of the exhaust manifold and the internal combustion engine despite positional tolerance differences there between.

An engine system includes a cylinder block, and a cylinder head attached to the cylinder block and including exhaust ports. Exhaust collection passages are formed in the cylinder head and each fluidly connect to one of the exhaust ports. An unburned hydrocarbon (UHC) emissions mitigation conduit fluidly connects to the exhaust ports to route UHC to an oxidation catalyst or for recirculation.