A cylinder head of an engine in which a thermal stress acting between a valve seat made of clad material and a base metal is reduced. The cylinder head comprises: an inner wall surface; a pair of intake ports arranged adjacent to each other; a valve seat formed of clad material around each intake port; a mask section formed within a predetermined range of a circumference of each intake port to protrude toward a combustion chamber; and a cavity formed between a pair of the mask sections by partially depressing the inner wall surface toward the combustion chamber.

A cylinder head of an engine in which a thermal stress acting between a valve seat made of clad material and a base metal is reduced. The cylinder head comprises: an inner wall surface; a pair of intake ports arranged adjacent to each other; a valve seat formed of clad material around each intake port; a mask section formed within a predetermined range of a circumference of each intake port to protrude toward a combustion chamber; and a cavity formed between a pair of the mask sections by partially depressing the inner wall surface toward the combustion chamber.

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.

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 valve seat insert includes a top convex arcuate blend for improving fluid flow, and a valve seating surface for slowing down valve recession. The valve seating surface includes a radially outer convex arcuate segment defining an outer radius of curvature forming a first wear crown for contacting the valve at an early wear state, a radially inner convex arcuate segment defining an inner radius of curvature forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the radially outer convex arcuate segment and the radially inner convex arcuate segment.

A valve seat insert includes a top convex arcuate blend for improving fluid flow, and a valve seating surface for slowing down valve recession. The valve seating surface includes a radially outer convex arcuate segment defining an outer radius of curvature forming a first wear crown for contacting the valve at an early wear state, a radially inner convex arcuate segment defining an inner radius of curvature forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the radially outer convex arcuate segment and the radially inner convex arcuate segment.

A valve seat insert includes a top convex arcuate blend for improving fluid flow, and a valve seating surface for slowing down valve recession. The valve seating surface includes a radially outer convex arcuate segment defining an outer radius of curvature forming a first wear crown for contacting the valve at an early wear state, a radially inner convex arcuate segment defining an inner radius of curvature forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the radially outer convex arcuate segment and the radially inner convex arcuate segment.

A valve seat insert includes a top convex arcuate blend for improving fluid flow, and a valve seating surface for slowing down valve recession. The valve seating surface includes a radially outer convex arcuate segment defining an outer radius of curvature forming a first wear crown for contacting the valve at an early wear state, a radially inner convex arcuate segment defining an inner radius of curvature forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the radially outer convex arcuate segment and the radially inner convex arcuate segment.