A method for manufacturing an engine poppet valve may comprise a forging operation, a diameter-decreasing operation, and a joining operation. At the forging operation, an intermediate member at which a valve head portion and an intermediate stem portion are made integral by way of a neck portion may be formed. At the diameter-decreasing operation, the intermediate stem portion may be inserted between/among a plurality of diameter-decreasing tools that have stem member compressing surfaces and stem member inlet surfaces formed so as to be progressively distant from the stem member compressing surfaces and toward the tip end and that are arranged at a plurality of circumferentially equipartite locations about a circumference of the intermediate stem portion, application at the intermediate stem portion from a base end portion of compressive forces which are inwardly directed in a radial direction from the compressing surfaces of the respective diameter-decreasing tools which have been made to come in contact with a part of the intermediate stem portion that has been made to rotate while being displaced in relative fashion in a direction along a central axis thereof causing the part of the intermediate stem portion to be decreased in diameter from the base end portion and causing a main body portion of a first stem portion to be formed at the intermediate member and also causing formation by the compressing surfaces of a stepped portion which is continuous with the main body portion, and formation, by an absence of decrease in diameter of a remaining portion at the intermediate stem portion, of a second stem portion which is broader in girth than the main body portion and which is continuous with the neck portion and which is also continuous with the main body portion by way of the stepped portion. At the joining operation, a stem end member having a same outside diameter as the main body portion may be joined to a base end portion of the main body portion.

A valve seat ring for a gas exchange valve of a cylinder of an internal combustion engine includes: a one-part or multi-part main body defining a through-flow opening; and a valve seat region arranged on a portion of the main body in the region of the through-flow opening, a surface of the valve seat region forming a valve seat for a valve body of the gas exchange valve. At least into the main body at least one recess is introduced, which is at least partly filled with a solder material.

A method for manufacturing an internally cooled valve (2), includes providing a valve body (4) having a valve stem (6) that ends in a valve head (8). The valve body (4) has a cavity (10) that is open toward the valve head (8) and with a valve base element (12) by friction welding the valve base element (12) to the valve head (8). The valve bottom element (12) is preferably a sintered component.

A method for manufacturing an internally cooled valve (2), includes providing a valve body (4) having a valve stem (6) that ends in a valve head (8). The valve body (4) has a cavity (10) that is open toward the valve head (8) and with a valve base element (12) by friction welding the valve base element (12) to the valve head (8). The valve bottom element (12) is preferably a sintered component.

A matrix for shaping a valve preform has a circular through opening and a reduced conical section. The reduced conical section tapers from an outer diameter to a reduced cone inner diameter, the outer diameter being greater than or equal to the initial outer diameter of the valve preform, and the matrix inner diameter being smaller than the initial outer diameter.

Improved multi-section slide valves for internal combustion engines for improved aspiration comprise spaced apart, continuously pressurized, annular oil confinement zones that are defined between select groups of arrays of piston rings. The oil confinement zones are axially spaced along the length of the slide valve and continuously pressured by oil flow passageways communicating between spaced apart arrays of piston rings. During slide valve movement these pressurized oil confinement zones tend to stabilize the slide valve, preventing metal-to-metal contact such as that associated with rocking, tipping, chafing or scrubbing.

Improved multi-section slide valves for internal combustion engines for improved aspiration comprise spaced apart, continuously pressurized, annular oil confinement zones that are defined between select groups of arrays of piston rings. The oil confinement zones are axially spaced along the length of the slide valve and continuously pressured by oil flow passageways communicating between spaced apart arrays of piston rings. During slide valve movement these pressurized oil confinement zones tend to stabilize the slide valve, preventing metal-to-metal contact such as that associated with rocking, tipping, chafing or scrubbing.

A internally cooled poppet valve (2) with inertial pump (4) includes a valve body (20) having a valve head (22) and a valve stem (24). The valve body (20) has a closed cavity (26), in which a cooling fluid (28) is disposed. The inertial pump (4) is disposed in the valve body (20), which moves the cooling fluid (28) in the cavity during operation.

A internally cooled poppet valve (2) with inertial pump (4) includes a valve body (20) having a valve head (22) and a valve stem (24). The valve body (20) has a closed cavity (26), in which a cooling fluid (28) is disposed. The inertial pump (4) is disposed in the valve body (20), which moves the cooling fluid (28) in the cavity during operation.

In a hollow exhaust poppet valve including a fillet increasing in diameter toward a leading end, a stem, and a head and having a coolant within a hollow part formed from the head to the stem, the stem includes a first stem part on a base end side, and a second stem part integrated with the first stem part via a step part and integrated with the fillet, and the hollow part includes a first hollow part formed inside the first stem part, and a second hollow part formed inside the second stem part, the fillet, and the head in such fashion as to have a constant inner diameter greater than the first hollow part and formed so as to be continuous with the first hollow part via a tapered part or a curved part.