An assembly of a cylinder head and a fuel injector with an injector tip for an internal combustion engine with at least one combustion chamber, wherein the fuel injector at the end facing a combustion chamber of the internal combustion engine is at least partially surrounded by a heat shield, wherein in the region of the heat shield a heat dissipation device is provided, through which heat can be dissipated from the combustion chamber of the internal combustion engine, wherein the heat shield surrounds the fuel injector as far as the injector tip, wherein the heat shield is designed as a tapering collar towards the injector tip and is integrated into an injector sleeve or into the cylinder head.

An assembly of a cylinder head and a fuel injector with an injector tip for an internal combustion engine with at least one combustion chamber, wherein the fuel injector at the end facing a combustion chamber of the internal combustion engine is at least partially surrounded by a heat shield, wherein in the region of the heat shield a heat dissipation device is provided, through which heat can be dissipated from the combustion chamber of the internal combustion engine, wherein the heat shield surrounds the fuel injector as far as the injector tip, wherein the heat shield is designed as a tapering collar towards the injector tip and is integrated into an injector sleeve or into the cylinder head.

A cylinder head assembly includes a cylinder head having an igniter mount that forms a portion of a fireside surface of the cylinder head. The assembly further includes a sleeve abutting the igniter mount within an igniter bore in the cylinder head, such that the sleeve and the cylinder head together form an igniter cooling passage circumferential of the igniter mount, and extending axially between the sleeve and the cylinder head. The configuration of the igniter mount and sleeve improves heat dissipation and reduces likelihood of pre-ignition in an internal combustion engine.

An internal combustion engine includes a cylinder block, a cylinder-block passage, a cylinder head, a cylinder-head passage, cylinders, an introducing portion, a restricting wall, and communicating portions. The introducing portion is configured to introduce coolant flowing in the cylinder-head passage into an EGR cooler. The restricting wall is configured to restrict flow of the coolant from a section corresponding to the spark plug toward the introducing portion. The communicating portions cause the cylinder-block passage and the cylinder-head passage to communicate with each other. A direction perpendicular to both the extending direction of the central axis of each cylinder and the cylinder arrangement direction is defined as a predetermined direction. Certain one or certain ones of the communicating portions are arranged at positions closer to an intake manifold than the restricting wall in the predetermined direction.

A prechamber assembly for an internal combustion engine is disclosed. The prechamber assembly may have a prechamber housing with a first prechamber housing portion and a second prechamber housing portion. The first prechamber housing portion and the second prechamber housing portion may define a prechamber volume. The prechamber assembly may also have a cooling system. The cooling system may be configured to cool at least one of the first prechamber housing portion and the second prechamber housing portion based on a flow of a cooling fluid through the cooling system. The cooling system may have at least one cooling channel formed within the prechamber housing.

A prechamber assembly for an internal combustion engine is disclosed. The prechamber assembly may have a prechamber housing with a first prechamber housing portion and a second prechamber housing portion. The first prechamber housing portion and the second prechamber housing portion may define a prechamber volume. The prechamber assembly may also have a cooling system. The cooling system may be configured to cool at least one of the first prechamber housing portion and the second prechamber housing portion based on a flow of a cooling fluid through the cooling system. The cooling system may have at least one cooling channel formed within the prechamber housing.

A cylinder head comprises a cylinder head body. The cylinder head body has two intake ports placed on a first side of the cylinder head body with respect to the plug hole, and the two exhaust ports placed on a second side of the cylinder head body with respect to the plug hole. A water jacket of the cylinder head includes: an intake-port-to-intake-port passage portion communicating with the outside of the cylinder head and extending between the two intake ports; an exhaust-port-to-exhaust-port passage portion communicating with the outside of the cylinder head and extending between the two exhaust ports; and a central passage portion communicating with the intake-port-to-intake-port passage portion and the exhaust-port-to-exhaust-port passage portion, the central passage portion being formed so as to surround the plug hole.

A cylinder head comprises a cylinder head body. The cylinder head body has two intake ports placed on a first side of the cylinder head body with respect to the plug hole, and the two exhaust ports placed on a second side of the cylinder head body with respect to the plug hole. A water jacket of the cylinder head includes: an intake-port-to-intake-port passage portion communicating with the outside of the cylinder head and extending between the two intake ports; an exhaust-port-to-exhaust-port passage portion communicating with the outside of the cylinder head and extending between the two exhaust ports; and a central passage portion communicating with the intake-port-to-intake-port passage portion and the exhaust-port-to-exhaust-port passage portion, the central passage portion being formed so as to surround the plug hole.

A cylinder head for an internal combustion engine is provided, whereby the cylinder head has a cylinder head gasket region for closing a combustion chamber with a diameter. The cylinder head includes the following: a. two intake holes for receiving one intake valve each; b. two outlet holes for receiving one outlet valve each; and c. a spark plug sleeve hole for receiving a spark plug sleeve.

The at least one intake hole of the two intake holes has a diameter between 34.0% and 36.6% of the diameter of the combustion chamber, preferably a diameter between 34.5% and 35.9% of the diameter of the combustion chamber, and particularly preferably a diameter between 34.8% and 35.5% of the diameter of the combustion chamber. The at least one outlet hole has a diameter that, in relation to the diameter of the combustion chamber, is at least 1% smaller than the diameter of the intake holes.

An ignition plug includes a tubular insulator, a metallic shell disposed around the outer circumference of the insulator, a center electrode disposed in an axial hole of the insulator, and a ground electrode connected to the forward end of the metallic shell and facing the center electrode. The metallic shell has a threaded portion to be engaged with an internal combustion engine. The relational expression Ss/(Sa+Sb)2.6 is satisfied, where Ss is the surface area of an outer circumferential surface of the metallic shell extending from the rear end of the threaded portion to the forward end of the threaded portion, Sa is the surface area of that portion of the metallic shell which is to be exposed to combustion gas of the internal combustion engine, and Sb is the surface area of that portion of the insulator which is to be exposed to the combustion gas.