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.

An internal combustion engine includes a valve seat insert within an engine housing, and a gas exchange valve. The valve seat insert has a compound valve seat with a valve recession-resistive profile formed by a leading radius contacted by the valve seat at an early wear state of the valve head and valve seat insert, a trailing radius contacted by the valve head at a later wear state of the valve head and valve seat insert, and an outer seat face. The compound valve seat is shaped and proportioned to cushion contact by a gas exchange valve and retard valve recession.

A gas exchange valve in an internal combustion engine includes a valve head having a sealing face structured to contact a valve seat and defining a face angle. The valve head further includes an under-head fillet transitioning from the inner sealing face to a valve stem, and defining a chordal stress zone within the under-head fillet. The under-head fillet is formed by a material distributed according to a stress-diffusing contour within the chordal stress zone, and is blended with the inner sealing face at a blend angle that is less than the face angle and is in a range of about 18 to about 35. The valve head contour is associated with resistance to chordal stress-induced fatigue failure.

A method for manufacturing a metallic component including the steps of providing a capsule, which defines at least a portion of the shape of the metallic component, arranging metallic material in the capsule, sealing the capsule, subjecting the capsule to Hot Isostatic Pressing for a predetermined time, at a predetermined pressure and at a predetermined temperature, and optionally, removing the capsule. The metallic material is at least one pre-manufactured coherent body, which pre-manufactured coherent body being made of metallic powder, wherein at least a portion of the metallic powder is consolidated such that the metallic powder is held together into a pre-manufactured coherent body. At least one portion of the pre-manufactured coherent body is manufactured by Additive Manufacturing by subsequently arranging superimposed layers of metallic powder.

A method for manufacturing a metallic component including the steps of providing a capsule, which defines at least a portion of the shape of the metallic component, arranging metallic material in the capsule, sealing the capsule, subjecting the capsule to Hot Isostatic Pressing for a predetermined time, at a predetermined pressure and at a predetermined temperature, and optionally, removing the capsule. The metallic material is at least one pre-manufactured coherent body, which pre-manufactured coherent body being made of metallic powder, wherein at least a portion of the metallic powder is consolidated such that the metallic powder is held together into a pre-manufactured coherent body. At least one portion of the pre-manufactured coherent body is manufactured by Additive Manufacturing by subsequently arranging superimposed layers of metallic powder.

A two-stroke, opposed-piston engine includes a cylinder with an inlet piston controlled inlet port and an exhaust piston controlled exhaust port, the cylinder defining a combustion chamber with the inlet piston and the exhaust piston, a charge air channel in flow communication with the inlet port, a conduit extending directly from the combustion chamber to the charge air channel, and a valve arranged to selectively open and close flow communication through the conduit.

A valve seat insert for a gas exchange valve controlling gas exchange of a cylinder includes an insert body having an inner peripheral surface, an outer peripheral surface, and a valve seating surface structured to contact the gas exchange valve at a closed position and profiled to limit valve recession thereof. The valve seating surface includes an arrangement of linear segments and curved segments forming crowns to contact the gas exchange valve at different wear states.

An internal combustion engine includes a valve seat insert within an engine housing, and a gas exchange valve. The valve seat insert has a compound valve seat with a valve recession-resistive profile formed by a leading radius contacted by the valve seat at an early wear state of the valve head and valve seat insert, a trailing radius contacted by the valve head at a later wear state of the valve head and valve seat insert, and an outer seat face. The compound valve seat is shaped and proportioned to cushion contact by a gas exchange valve and retard valve recession.

An iron alloy powder consists of, when the entirety thereof is assumed to be 100 mass %, Cr: 2.5 mass % to 3.5 mass %, Mo: 0.4 mass % to 0.6 mass %, and Fe and inevitable impurities as the balance, a mixed powder consisting of 15 mass % to 40 mass % of the iron alloy powder, 1.2 mass % to 1.8 mass % of a copper powder, 0.5 mass % to 1.0 mass % of a graphite powder, and a pure iron powder as the balance when the entire mixed powder is assumed to be 100 mass % is compacted into a compact, and the compact is sintered while transforming a structure derived from the pure iron powder into a structure in which a ferritic structure and a pearlitic structure are mixed and transforming a structure derived from the iron alloy powder into a martensitic structure.

An iron alloy powder consists of, when the entirety thereof is assumed to be 100 mass %, Cr: 2.5 mass % to 3.5 mass %, Mo: 0.4 mass % to 0.6 mass %, and Fe and inevitable impurities as the balance, a mixed powder consisting of 15 mass % to 40 mass % of the iron alloy powder, 1.2 mass % to 1.8 mass % of a copper powder, 0.5 mass % to 1.0 mass % of a graphite powder, and a pure iron powder as the balance when the entire mixed powder is assumed to be 100 mass % is compacted into a compact, and the compact is sintered while transforming a structure derived from the pure iron powder into a structure in which a ferritic structure and a pearlitic structure are mixed and transforming a structure derived from the iron alloy powder into a martensitic structure.