Aspects of the present invention relate to a valve seat (20) for a poppet valve of an internal combustion engine, wherein the poppet valve comprises a head and a stem behind the head, the valve seat comprising: an aperture (21) configured to form a seal with the head of the poppet valve when the poppet valve is in a closed position; and a peripheral body (22) defining, at least in part, one or more ports (23) shaped like e.g. grooves and sized to enable injection of liquid or gas from a cylinder head of the internal combustion engine into a gas stream behind the head of the poppet valve.

Aspects of the present invention relate to a valve seat (20) for a poppet valve of an internal combustion engine, wherein the poppet valve comprises a head and a stem behind the head, the valve seat comprising: an aperture (21) configured to form a seal with the head of the poppet valve when the poppet valve is in a closed position; and a peripheral body (22) defining, at least in part, one or more ports (23) shaped like e.g. grooves and sized to enable injection of liquid or gas from a cylinder head of the internal combustion engine into a gas stream behind the head of the poppet valve.

An internal combustion engine comprising: an intake opening; an exhaust opening; and a mask part having a wall surface extending toward the inside of the combustion chamber along an outer periphery of the intake opening at an opposite side from the exhaust opening side. The wall surface of the mask part is formed so that a clearance from a passage surface of an edge part of the intake valve at an edge part at the lift direction side is greater than the clearance at the edge part at the opposite lift direction side, and so that between the edge part at the lift direction side and the edge part at the opposite lift direction side, the clearance is a value between the clearance at the edge part at the lift direction side and the clearance at the edge part at the opposite lift direction side.

A hydraulically variable gas exchange valve train for an internal combustion engine is proposed that includes a hydraulic housing with a pressure chamber, a pressure relief chamber, and a vent duct. The vent duct is connected hydraulically on a housing inner side via a restriction to the pressure relief chamber, and opens on the housing outer side below the pressure relief chamber with regard to a direction of gravity. The vent duct opens into a hydraulic reservoir, wherein the vent duct opening lies below a normal level of the hydraulic reservoir with regard to the direction of gravity.

A hydraulically variable gas exchange valve train for an internal combustion engine is proposed that includes a hydraulic housing with a pressure chamber, a pressure relief chamber, and a vent duct. The vent duct is connected hydraulically on a housing inner side via a restriction to the pressure relief chamber, and opens on the housing outer side below the pressure relief chamber with regard to a direction of gravity. The vent duct opens into a hydraulic reservoir, wherein the vent duct opening lies below a normal level of the hydraulic reservoir with regard to the direction of gravity.

The present disclosure relates to a valve, preferably an exhaust gas or gas exchange valve, having a valve head which has a front face and a rear face, the front face of the valve head including an edge region and a bulge towards the outside which has a crest region. The valve, in order to reduce the mass of the bulge of the valve head, including a laterally outer part section of the edge region that is of flatter configuration in comparison with a laterally inner part section of the edge region, or the edge region includes at least one discontinuity in cross section.

The present disclosure relates to a valve, preferably an exhaust gas or gas exchange valve, having a valve head which has a front face and a rear face, the front face of the valve head including an edge region and a bulge towards the outside which has a crest region. The valve, in order to reduce the mass of the bulge of the valve head, including a laterally outer part section of the edge region that is of flatter configuration in comparison with a laterally inner part section of the edge region, or the edge region includes at least one discontinuity in cross section.

Methods and systems are provided for generating tumble in intake air by creating an asymmetrical annulus opening for flowing intake air into a combustion chamber of an engine cylinder. The asymmetrical annulus opening may be created by changing an angle of an intake valve disc of an intake valve. The angle of the intake valve disc may be varied based on engine operating parameters by extending or retracting one or more connect rods coupled to an annulus tumble guide movably housed inside an annulus channel.

A valve arrangement for supplying air to an internal combustion engine includes a first valve and a second valve arranged within the first valve. A valve guide for use in a valve arrangement is also provided.

A valve arrangement for supplying air to an internal combustion engine includes a first valve and a second valve arranged within the first valve. A valve guide for use in a valve arrangement is also provided.