A water jacket for a cylinder head provided inside a cylinder head including a protruded part formed with an exhaust outlet exhausting an exhaust gas includes an upper water jacket for moving a coolant on an exhaust passage connected with the exhaust outlet inside the protruded part, a lower water jacket for moving a coolant under an exhaust passage connected with the exhaust outlet inside the protruded part, and at least one connection part mutually connecting the upper water jacket and the lower water jacket to enable the flow of coolant to a side of the exhaust outlet from the inside of the protruded part.

Disclosed are integrated exhaust manifold (IEM) cylinder heads, methods for making and methods for using IEM cylinder heads, and motor vehicles with an engine and IEM cylinder head assembly. Disclosed, for example, is an IEM cylinder head for a motor vehicle with an engine and an exhaust system. The IEM cylinder head includes a body that mounts to the engine's cylinder block. The cylinder head body integrally defines: multiple chamber surfaces each aligning with a cylinder bore and piston to define a combustion chamber; multiple exhaust ports each communicating with a cylinder bore to evacuate exhaust gas therefrom; multiple exit ports communicating with the exhaust system to evacuate exhaust gas from the cylinder head; and multiple exhaust runners each extending from an exhaust port to one exit port. These exhaust runners are fluidly isolated from each other to each transmit exhaust gases from a single one of the cylinder bores.

A cylinder head assembly for an internal combustion engine is provided. In one example implementation, the cylinder head assembly includes a cylinder head, a bypass passage formed within the cylinder head and defining a catalyst cavity, and a bypass catalytic converter disposed within the catalyst cavity, where the bypass catalytic converter is configured to provide emissions reduction during cold start, long idle, and/or low main catalytic converter temperature conditions.

A two-stroke internal combustion engine has an engine block having a cylinder block and a cylinder head. The cylinder block defines a cylinder, an exhaust passage, and an exhaust valve passage. The engine also has a piston, an exhaust valve actuator operatively connected to at least one of the cylinder block and the cylinder head, and a reciprocating exhaust valve disposed at least in part in the exhaust valve passage. The exhaust valve has a shaft operatively connected to a valve actuator, and a blade connected to the shaft. A channel is defined along a face of the blade. The channel and a wall of the exhaust valve passage together define at least in part a valve passage. The valve passage permits flow of exhaust gas along the face of the blade. A width of the valve passage is at least a third of a width of the blade.

A piston for an internal combustion engine includes a plurality of valve pockets formed in a piston rim, the valve pockets forming fluid flow paths through the piston rim. Each of the valve pockets includes a central step standing proud of a pocket floor to limit a fluid flow area through the pocket and slow combustion gas flow from a combustion bowl toward a cylinder liner and thereby reduce displacement of an engine oil film thereon.

The disclosure relates to a cylinder head for covering a combustion chamber of an internal combustion engine. The cylinder head comprises at least one material recess for heat isolation, which is formed in a main body of the cylinder head and is arranged between a fluid-guide channel and a cooling channel. The material recess can be produced e.g. directly during the shaping (e.g. casting or pressing) of the cylinder head and/or thereafter. For example, in the event that exhaust gas is guided through the fluid-guide channel, a significantly lower heat input occurs from the hot exhaust gas into the cooling fluid. In addition, the thermal decoupling via the material recess leads to the hot exhaust gas cooling to a lesser degree in the fluid-guide channel.

A reciprocating exhaust valve for a two-stroke internal combustion engine has a shaft for connection to a valve actuator, the shaft defining a reciprocation axis of the valve, the reciprocation axis defining a longitudinal direction of the valve; and a blade having: a first end having an arcuate edge, a second end connected to the shaft, two side portions, and a central portion. The blade has a first end portion adjacent the first end that includes a part of the central portion and of each of the two side portions. A width of the central portion is greater than a width of each of the side portions. In the first end portion, a thickness of the part of each of the two side portions is greater than a thickness of the part of the central portion.

A method of forming a thermally isolated exhaust port, the method comprising applying an endothermic material to an exhaust port core in a mold for an engine cylinder head, forming the engine cylinder head with an exhaust port using a casting process, generating, in the cylinder head with the exhaust port during the casting process, nodular graphite iron proximate the endothermic material around the exhaust port core, and forming the thermally isolated exhaust port containing nodular graphite iron in the cylinder head.

A reciprocating exhaust valve for a two-stroke internal combustion engine has a shaft for connection to a valve actuator, the shaft defining a reciprocation axis of the valve, the reciprocation axis defining a longitudinal direction of the valve; and a blade having: a first end having an arcuate edge, a second end connected to the shaft, two side portions, and a central portion. The blade has a first end portion adjacent the first end that includes a part of the central portion and of each of the two side portions. A width of the central portion is greater than a width of each of the side portions. In the first end portion, a thickness of the part of each of the two side portions is greater than a thickness of the part of the central portion.

An exhaust valve system for a two-stroke internal combustion engine having: at least one exhaust valve movable between open and closed positions; an actuator for moving the at least one exhaust valve; a valve position sensor; a controller communicating with the actuator and the valve position sensor. The controller being programmed for: controlling the actuator to attempt to move the at least one exhaust valve to a desired one of the open and closed positions; determining if the at least one exhaust valve has failed to reach the desired position based on the position of the at least one exhaust valve sensed by the valve position sensor; and controlling the actuator to move the at least one exhaust valve to an intermediate position when the at least one exhaust valve has failed to reach the desired position.