Caterpillar Inc.
Valve seat insert for high power density and marine engines

Abstract:

A valve seat insert of an engine has a valve seating surface including an outer curved segment forming a first wear crown for contacting the valve at an early wear state, an inner curved segment forming a second wear crown for contacting the valve at a later wear state, and a linear segment extending between the outer and the inner curved segments. A sloping segment is oriented at an acute angle relative to the valve seat center axis, forming a venturi or a diffuser for gases entering or exiting the cylinder.