A ducted combustion system includes a combustion chamber and a fuel injector in fluid connection with the combustion chamber, which includes an orifice opening from an injector tip of the fuel injector, the orifice injecting fuel into the combustion chamber as a fuel jet, the fuel jet flowing, within the combustion chamber, in a fuel flow direction. The system includes at least one duct disposed within the combustion chamber, the at least one duct being disposed such that the fuel jet, at least partially, enters one of the at least one ducts upon being injected into the combustion chamber. The at least one duct may be configured for having a flow field air stream within the duct, prior to entrance of the fuel jet, the flow field air stream having a flow direction that is substantially similar to the fuel flow direction.

A ducted combustion system includes a combustion chamber and a fuel injector in fluid connection with the combustion chamber, which includes an orifice opening from an injector tip of the fuel injector, the orifice injecting fuel into the combustion chamber as a fuel jet, the fuel jet flowing, within the combustion chamber, in a fuel flow direction. The system includes at least one duct disposed within the combustion chamber, the at least one duct being disposed such that the fuel jet, at least partially, enters one of the at least one ducts upon being injected into the combustion chamber. The at least one duct may be configured for having a flow field air stream within the duct, prior to entrance of the fuel jet, the flow field air stream having a flow direction that is substantially similar to the fuel flow direction.

An engine includes a cylinder liner, a cylinder block, a cylinder head, a seal portion, and a gap member. The seal part is provided to surround the outer circumferential side of the cylinder liner and configured to seal between the cylinder block and the cylinder head. At a position on the inner circumferential side of the seal part, the gap member fills the gap between the cylinder head and the end surface of the inner peripheral side of the cylinder liner, and is made of a material having a lower Young's modulus than the seal part.

An engine includes a cylinder liner, a cylinder block, a cylinder head, a seal portion, and a gap member. The seal part is provided to surround the outer circumferential side of the cylinder liner and configured to seal between the cylinder block and the cylinder head. At a position on the inner circumferential side of the seal part, the gap member fills the gap between the cylinder head and the end surface of the inner peripheral side of the cylinder liner, and is made of a material having a lower Young's modulus than the seal part.

An engine block comprising: a combustion chamber, an inlet for introducing a fuel/air mixture into the combustion chamber and an outlet for expelling combusted fuel/air mixture from the combustion chamber; and a piston that reciprocates within the combustion chamber to compress the fuel/air mixture therein, the piston having a closer supported thereon, wherein reciprocating movement of the piston seals the combustion chamber with the closer.

A ducted combustion system for an internal combustion engine includes a combustion chamber, a fuel injector, and a plurality of ducts. The combustion chamber is defined between a flame deck surface of a cylinder head and a piston crown of a piston disposed within a cylinder bore. Further, the fuel injector is configured to inject fuel into the combustion chamber as a plurality of fuel jets. The plurality of ducts is disposed within the combustion chamber between the flame deck surface and the piston crown. The plurality of ducts is disposed such that each of the plurality of fuel jets at least partially enters one of the plurality of ducts. The at least one of the plurality of ducts is configured to move to vary an angle of a corresponding at least one of the plurality of fuel jets relative to a longitudinal axis of the fuel injector.

A ducted combustion system for an internal combustion engine includes a combustion chamber, a fuel injector, and a plurality of ducts. The combustion chamber is defined between a flame deck surface of a cylinder head and a piston crown of a piston disposed within a cylinder bore. Further, the fuel injector is configured to inject fuel into the combustion chamber as a plurality of fuel jets. The plurality of ducts is disposed within the combustion chamber between the flame deck surface and the piston crown. The plurality of ducts is disposed such that each of the plurality of fuel jets at least partially enters one of the plurality of ducts. The at least one of the plurality of ducts is configured to move to vary an angle of a corresponding at least one of the plurality of fuel jets relative to a longitudinal axis of the fuel injector.

An engine includes: a piston including a cavity; a cylinder head configured to form a combustion chamber having a pent roof shape; a fuel injection valve configured to inject fuel from a second half of a compression stroke until a first half of an expansion stroke; and a spark plug arranged at a position corresponding to an upper side of the cavity. Injection openings are arranged in a circumferential direction surrounding a longitudinal axis of the valve. The combustion chamber at a compression top dead center is divided into a plurality of fuel injection regions, located in respective injection directions of the injection openings, by vertical surfaces extending radially from the longitudinal axis through a middle between adjacent injection openings. When a volume of the fuel injection region located in the injection direction of the injection opening is large, an opening area of the injection opening is large.

A combustion system is provided for an internal combustion engine including a cylinder head and a piston. In one example, a combustion system may include a cylinder head with a second cylinder surface angled relative to a first cylinder surface, an intake port coupled to the first cylinder surface, an exhaust port coupled to the second cylinder surface, and a piston with a first piston surface parallel to the first cylinder surface and a second piston surface parallel to the second cylinder surface.

A combustion system is provided for an internal combustion engine including a cylinder head and a piston. In one example, a combustion system may include a cylinder head with a second cylinder surface angled relative to a first cylinder surface, an intake port coupled to the first cylinder surface, an exhaust port coupled to the second cylinder surface, and a piston with a first piston surface parallel to the first cylinder surface and a second piston surface parallel to the second cylinder surface.