A system includes an engine head that mounts to an engine block of a reciprocating engine, and the engine head includes an intake flow path, an exhaust flow path, a coolant flow path, and first and second sealing registers disposed on opposite sides of the coolant flow path. In addition, the first and second sealing registers are configured to receive a valve guide that supports a valve stem of an exhaust valve. Moreover, the first sealing register is disposed in a wall separating the exhaust flow path and the coolant flow path. Also, a first wall portion of the wall extends between the first sealing register and an exhaust valve seat configured to receive a valve head of the exhaust valve, and a second wall portion of the wall extends from the first sealing register away from the first wall portion.

A system includes an engine head that mounts to an engine block of a reciprocating engine, and the engine head includes an intake flow path, an exhaust flow path, a coolant flow path, and first and second sealing registers disposed on opposite sides of the coolant flow path. In addition, the first and second sealing registers are configured to receive a valve guide that supports a valve stem of an exhaust valve. Moreover, the first sealing register is disposed in a wall separating the exhaust flow path and the coolant flow path. Also, a first wall portion of the wall extends between the first sealing register and an exhaust valve seat configured to receive a valve head of the exhaust valve, and a second wall portion of the wall extends from the first sealing register away from the first wall portion.

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.

In an internal combustion engine provided with a combustion chamber defined by an inner circumferential surface of a cylinder, an end surface of a cylinder head facing the cylinder, a crown surface of a piston, an inner surface of an intake valve, and an inner surface of an exhaust valve, for the purpose of improving the anti-knocking performance of the engine, the inner circumferential surface of the cylinder, the end surface of the cylinder head, the crown surface of the piston, the inner surface of the intake valve and the inner surface of the exhaust valve include a mirror surface region formed as a mirror surface having an arithmetic average roughness of 0.3 μm or less, and a rough surface region formed as a rough surface having an arithmetic average roughness of 0.3 μm or more.

In an internal combustion engine provided with a combustion chamber defined by an inner circumferential surface of a cylinder, an end surface of a cylinder head facing the cylinder, a crown surface of a piston, an inner surface of an intake valve, and an inner surface of an exhaust valve, for the purpose of improving the anti-knocking performance of the engine, the inner circumferential surface of the cylinder, the end surface of the cylinder head, the crown surface of the piston, the inner surface of the intake valve and the inner surface of the exhaust valve include a mirror surface region formed as a mirror surface having an arithmetic average roughness of 0.3 μm or less, and a rough surface region formed as a rough surface having an arithmetic average roughness of 0.3 μm or more.

A cylinder head for use with an internal combustion engine, the cylinder head including a body having a fire deck and defining a water jacket in fluid communication with a cooling system. The cylinder head also includes a first runner defined by the body and open to the fire deck to at least partially form a first valve seat, a second runner defined by the body and open to the fire deck to at least partially form a second valve seat, and a channel defined by the body, where the cooling channel is in fluid communication with the water jacket and positioned between the first runner and the second runner, and where the cooling channel includes a flow diverter configured to produce a turbulent region proximate the fire deck.

A cylinder head for use with an internal combustion engine, the cylinder head including a body having a fire deck and defining a water jacket in fluid communication with a cooling system. The cylinder head also includes a first runner defined by the body and open to the fire deck to at least partially form a first valve seat, a second runner defined by the body and open to the fire deck to at least partially form a second valve seat, and a channel defined by the body, where the cooling channel is in fluid communication with the water jacket and positioned between the first runner and the second runner, and where the cooling channel includes a flow diverter configured to produce a turbulent region proximate the fire deck.

A cylinder head arrangement for an internal combustion engine is provided. The cylinder head includes an integrated exhaust manifold having first and second exhaust passages to collect exhaust gas from respective cylinders to direct the exhaust gas to respective outlets of the cylinder head. The cylinder head includes a flange where the first and second outlets exit the cylinder head for connection with a turbocharger.

A cylinder head arrangement for an internal combustion engine is provided. The cylinder head includes an integrated exhaust manifold having first and second exhaust passages to collect exhaust gas from respective cylinders to direct the exhaust gas to respective outlets of the cylinder head. The cylinder head includes a flange where the first and second outlets exit the cylinder head for connection with a turbocharger.

The cylinder head includes an intake port communicating with a cylinder of a cylinder block, a cylinder head main body having an exhaust port communicating with the cylinder, and a rocker housing integrally formed on the cylinder head main body and an inner side of which is defined as a valve-system accommodating space. The rocker housing includes a lateral wall having a lateral wall main body and a base end portion which extends along a lower end of the lateral wall main body, connects the lateral wall main body to the cylinder head main body, and has a thickness thicker than that of the lateral wall body. A flow path which extends in an extending direction of the base end portion and through which a fluid flow is formed in the base end portion.