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 piston for an internal combustion engine includes a plurality of valve pockets formed in a piston rim, the valve pockets forming fluid flow paths through the piston rim. Each of the valve pockets includes a central step standing proud of a pocket floor to limit a fluid flow area through the pocket and slow combustion gas flow from a combustion bowl toward a cylinder liner and thereby reduce displacement of an engine oil film thereon.

A piston for an internal combustion engine includes a plurality of valve pockets formed in a piston rim, the valve pockets forming fluid flow paths through the piston rim. Each of the valve pockets includes a central step standing proud of a pocket floor to limit a fluid flow area through the pocket and slow combustion gas flow from a combustion bowl toward a cylinder liner and thereby reduce displacement of an engine oil film thereon.

An engine head assembly includes a valve seat insert having a valve seating surface defining a center axis, and each of an inner peripheral surface and an outer peripheral surface extending circumferentially around the valve seat center axis. The outer peripheral surface includes an upper section interference-fitted with the engine head, and a lower section. A stiffness relief channel is formed by a relief cutout in the valve seat insert, and extends radially between the lower section of the outer peripheral surface and the engine head. The stiffness relief channel permits flexing of the valve seat insert to cushion valve seating to prolong engine valve and valve seat insert service life.

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.

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 cooling system for a cylinder head of an internal combustion engine includes a cylindrical seat configured to engage an exhaust valve, a first coolant jacket, and a first conduit. The exhaust valve seat defines an annular cooling passage extending along a circumference of the cylindrical seat. A wall of the cylindrical seat defines a first opening into the annular cooling passage and a second opening into the annular cooling passage, where the first opening is positioned diametrically opposite to the second opening. The first coolant jacket is positioned adjacent to a fire-deck of the internal combustion engine. The first conduit fluidly couples the first coolant jacket to the at least one of the first opening and the second opening to the annular cooling passage in the exhaust valve seat.