An engine block assembly includes a head structure assembly, and a cylinder structure assembly. A plurality of fasteners interconnect the head structure assembly and the cylinder structure assembly. An outer shell encapsulates and supports both the head structure assembly and the cylinder structure assembly. The outer shell is a unitary polymer structure that is simultaneously over-molded onto the head structure assembly and the cylinder structure assembly. The head structure assembly and the cylinder structure assembly are constructed of components that are designed to carry the operational loads of the engine with minimal weight. The outer shell provides additional structural integrity, and provides fluid passages for lubrication and cooling, as well as support for other engine components.

A cylinder head for an internal combustion engine, includes: first and second valves being intake valves or exhaust valves; a first circumferential wall portion defining a first port, the first port being opened and closed by the first valve and communicating with a combustion chamber; and a first overlay welded portion formed on the first circumferential wall portion and serving as a first valve seat on which the first valve is seated.

An engine includes a cylinder block, a cylinder head, and a piston. The cylinder head is connected to the cylinder block. The piston is movably connected to the cylinder block. The cylinder block, the cylinder head, and the piston form a combustion chamber. The cylinder head includes an intake valve hole and an exhaust valve hole. An intake valve is disposed at the intake valve hole and an exhaust valve is disposed at the exhaust valve hole. A barrier protrusion is protruded at the edge of the intake valve hole away from the exhaust valve hole. The included angle between a first connecting line connecting a first end of the barrier protrusion and a center of the intake valve hole and a second connecting line connecting a second end of the barrier protrusion and the center of the intake valve hole is greater than 120 degrees and less than or equal to 180 degrees.

Provided is an engine with a starter valve arranged in a compact space and with a cylinder head having a cooling water passage and a starter valve feeding compressed air to a combustion chamber. The starter valve is arranged parallel in the axial direction to a cylinder while fitted into a sleeve, and a portion of the cooling water passage is formed by the outer surface of the sleeve fitted into a starter valve insertion hole formed in the cylinder head. A starting air passage orthogonal to the axial direction of the starter valve insertion hole is formed in the cylinder head, and a portion of the wall surface of the starting air passage is formed by the end surface on one side of the sleeve.

An engine block assembly includes a head structure assembly, and a cylinder structure assembly. A plurality of fasteners interconnect the head structure assembly and the cylinder structure assembly. An outer shell encapsulates and supports both the head structure assembly and the cylinder structure assembly. The outer shell is a unitary polymer structure that is simultaneously over-molded onto the head structure assembly and the cylinder structure assembly. The head structure assembly and the cylinder structure assembly are constructed of components that are designed to carry the operational loads of the engine with minimal weight. The outer shell provides additional structural integrity, and provides fluid passages for lubrication and cooling, as well as support for other engine components.

A cylinder structure of a diesel engine in which diesel fuel is ignited by a self-ignition manner includes a cylinder including a cylinder body in which a combustion chamber is formed and a cylinder head covering an upper portion of the cylinder body, at least one intake valve included in an intake port formed in the cylinder head, at least one exhaust valve included in an exhaust port formed in the cylinder head, and a diesel injector mounted at the center of the cylinder head and injecting diesel fuel. A lower surface of the cylinder head may be formed in a pent roof shape.

A combustion engine includes, a cylinder head including a controllable first engine valve arranged to selectively open/close a combustion chamber included in the combustion engine, a first valve actuator operatively connected to the first engine valve, which first valve actuator includes at least one inlet opening for pressure fluid and at least one outlet opening for pressure fluid, and a closed pressure fluid circuit, wherein the first valve actuator is arranged in the closed pressure fluid circuit. The combustion engine further includes a cylinder head chamber that forms part of the closed pressure fluid circuit and that is delimited by the cylinder head and at least a first cylinder head mantle, wherein the at least one outlet opening of the first valve actuator is in fluid communication with the cylinder head chamber. A mantle assembly for a cylinder head of a combustion engine is also described.

Intake holes at the opposite ends are opened and closed by first intake valves. The middle intake hole is opened and closed by a second intake valve. A control device includes an intake variable valve device. First branch channels are connected to the intake holes and produce a normal tumble flow. A second branch channel is configured such that the flow rate of intake air passing through the middle intake hole is relatively greater on the side closer to the outer periphery of the combustion chamber. Where increasing the flow coefficient is given a higher priority, a three-valve drive mode is selected. Where the strength of the normal tumble flow is enhanced, a two-valve drive mode is selected. Where production of the normal tumble flow is reduced, a one-valve drive mode is selected.

An internal combustion engine includes an intake port configured to generate a swirl in a cylinder, an exhaust port, and a piston. The piston includes a top surface provided in an upper portion of the piston, a cavity provided from the top surface toward a lower portion of the piston around a central axis of the piston, and a connection surface connecting an inner edge of the top surface and an upper end of a side surface of the cavity to each other. The connection surface is provided to be closer to a lower portion side of the piston than the top surface. An area of the connection surface projected on a plane parallel to the top surface is larger on an intake port side than on an exhaust port side.

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.