An engine valve includes a stem, a head comprising an outer lip surface, a seating surface extending from the outer lip surface toward the stem, and a combustion surface extending from the outer lip surface on the opposite side of the head as compared to the seating surface. The combustion surface includes a first convex arcuate surface spaced away from the outer lip surface, at least partially forming a raised ring, and a first concave arcuate surface spaced away from the outer lip surface, at least partially forming a dimple.

A poppet valve includes a head and a stem, which extends from the head. At least a part of the back of the head is covered by a cover with a heat insulating space provided in between. A support portion is provided between the cover and the head to support the cover on the head with rubber member having a lower heat conductivity than that of the head between the cover and the head.

A poppet valve includes a head and a stem, which extends from the head. At least a part of the back of the head is covered by a cover with a heat insulating space provided in between. A support portion is provided between the cover and the head to support the cover on the head with rubber member having a lower heat conductivity than that of the head between the cover and the head.

One exemplary embodiment of the present disclosure relates to an engine intake port structure. According to the engine intake port structure of the exemplary embodiment of the present disclosure, a chamfer is formed to be offset to either side from an end corner of an intake port. Accordingly, the inflow of a fuel gas is concentrated on a side in which an opening width of the chamfer is wide at the beginning of an opening stage when the intake port is opened/closed by a valve unit, and after the intake port is opened, the opening width is formed to be similar at four sides of the valve unit such that swirls formed in the fuel gas is weakened. That is, complete combustion of the fuel can be anticipated since the length of time during which the fuel gas remains in a combustion chamber is extended.

A system to attach valve seat inserts to an aluminum cylinder head of an automobile vehicle includes a cylinder head of an automobile vehicle engine having a valve seat portion. A valve seat insert is positioned in the valve seat portion of the cylinder head. A fusion bond is created between the valve seat insert and the valve seat portion by laser welding thereby fusing the valve seat insert to the valve seat portion.

A system to attach valve seat inserts to an aluminum cylinder head of an automobile vehicle includes a cylinder head of an automobile vehicle engine having a valve seat portion. A valve seat insert is positioned in the valve seat portion of the cylinder head. A fusion bond is created between the valve seat insert and the valve seat portion by laser welding thereby fusing the valve seat insert to the valve seat portion.

A method of operating an internal combustion engine having an electrical circuit that includes a connection closed by abutment between two distinct parts, one of which is mounted to a rocker arm of a rocker arm assembly and another that is mounted to a part distinct from the rocker arm. The connection is structured such that the movement of the rocker arm causes relative motion between the surfaces of the distinct parts that close the connection. The relative motion causes the circuit resistance to transition between values within a first range and values within a second range. The transitions of resistance between those ranges are detected and their presence, absence, or timing used for purposes of providing diagnostic feedback or control.

A method of operating an internal combustion engine having an electrical circuit that includes a connection closed by abutment between two distinct parts, one of which is mounted to a rocker arm of a rocker arm assembly and another that is mounted to a part distinct from the rocker arm. The connection is structured such that the movement of the rocker arm causes relative motion between the surfaces of the distinct parts that close the connection. The relative motion causes the circuit resistance to transition between values within a first range and values within a second range. The transitions of resistance between those ranges are detected and their presence, absence, or timing used for purposes of providing diagnostic feedback or control.

An engine valve includes a stem, a head comprising an outer lip surface, a seating surface extending from the outer lip surface toward the stem, and a combustion surface extending from the outer lip surface on the opposite side of the head as compared to the seating surface. The combustion surface includes a first convex arcuate surface spaced away from the outer lip surface, at least partially forming a raised ring, and a first concave arcuate surface spaced away from the outer lip surface, at least partially forming a dimple.

A method for introducing combustion air into a cylinder (25) of an internal combustion engine, a high-pressure inlet valve (1) provided therefor and an internal combustion engine that operates using the method and the high-pressure inlet valve are described. All the combustion air for the respective cylinders (25) is introduced into the cylinder (25) of the internal combustion engine, by means of a high-pressure inlet valve (1) arranged in the relevant cylinder head (26) and on the basis of a controlled mass flow, such that mixture formation and charge exchange are intensified. In addition, the temperature and/or pressure of the combustion air is measured and the quantity of combustion air is introduced into the cylinder (25), in a controlled manner and on the basis of the measurement results, by means of the high-pressure inlet valve (1) by opening or closing a sliding piston (3) of the high-pressure inlet valve (1) by displacement. As a result of an axial displacement of the sliding piston (3) between guide sections (5) in the housing (2) of the high-pressure inlet valve (1), passage areas (6) for combustion air are blocked in a closed position (7) and opened in an open position (8). In the passage area (6), the sliding piston (3) has two pressurization areas (10, 11) facing each other, the surfaces of which are of equal size or differ from each other when projected in one plane. The first pressurization area (10) can be designed as a poppet valve (12) and the second pressurization area (11) can be designed as an annular surface (13). The internal combustion engine has a high-pressure line (27) for the combustion air, which line is connected to the high-pressure inlet valve (1). With respect to the longitudinal axis of the cylinder (25), the high-pressure inlet valve (1) is arranged in the cylinder head (26) in an upright or horizontal position.