A motor vehicle cylinder head is provided with a single flat planar surface in which are formed spaced apart integral inlet and outlet ports used for connecting respective coolant supply and returns to a coolant jacket defined within the cylinder head. The use of a common planar surface for the location of the inlet and outlet ports provides a more reliable sealing of the cylinder head to the respective coolant supply and returns.

A cylinder head includes an exhaust port through which exhaust gas discharged out of a combustion chamber of an internal combustion engine passes. The cylinder head includes a first fin and a second fin projecting from an inner wall of the exhaust port and extending in a flow direction of the exhaust gas. The cylinder head includes a first projection projecting from the inner wall of the exhaust port and extending in a direction intersecting the first fin. The cylinder head also includes a second projection projecting from the inner wall of the exhaust port and extending in a direction intersecting the second fin.

An internal combustion engine includes a cylinder head assembly having a first group of exhaust ports and a second group of exhaust ports as well as an exhaust manifold integrated with the cylinder head assembly. The exhaust manifold includes a first runner in fluid communication with the first group of exhaust ports. The first runner defines a first exit configured for directing exhaust gas from the first group of exhaust ports to an EGR bypass passage and further defines a second exit configured for directing exhaust gas from the first group of exhaust ports to a turbocharger passage. The engine further includes a bypass valve assembly mounted to the exhaust manifold and having a bypass valve disposed within the first runner. The bypass valve is moveable between a turbine-closed position and an EGR-closed position.

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.

There is provided a secondary air introduction device configured to introduce air into an exhaust port provided in a cylinder head of an engine by using a negative pressure in the exhaust port. A back-flow restriction member is provided between a reed valve and the exhaust port in an air introduction passage, and includes a plate part intersecting with an extension direction of the air introduction passage. The plate part has an air passing region in which the air flowing through the air introduction passage from an air intake unit toward the exhaust port is enabled to pass therethrough and a back-flow cutoff region in which exhaust air, which flows in a direction of directly colliding with at least a valve body of the reed valve, of exhaust air flowing back through the air introduction passage from the exhaust port is cut off.

In a spark-ignition internal combustion engine in which a protrusion including an intake-side inclined surface and an exhaust-side inclined surface is formed on a top surface of a piston, and a cavity is formed in the protrusion at a position associated with a spark plug, the intake-side inclined surface and the exhaust-side inclined surface are formed in such a way that a ratio of a length of the exhaust-side inclined surface with respect to a length of the intake-side inclined surface is 1.25 or larger in a cross section passing through a center axis of the piston and orthogonal to an axis direction of a crankshaft.

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.

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 comprises 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.

Provided is a porous plate-shaped filler that can be used as a material for a heat-insulation film having excellent heat insulation performance. In a porous plate-shaped filler 1 having a plate shape, an aspect ratio is 3 or higher, a minimum length is 0.5 to 50 m, and an overall porosity is 20 to 90%, and the porosity is lower in the circumferential part than in the center part. When this porous plate-shaped filler 1 of the present invention is contained in a heat-insulation film, the infiltration of a matrix into the filler is reduced, and thus the thermal conductivity can be lowered. Therefore, even a thin heat-insulation film can have a greater heat-insulation effect than before.

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.