US Patent 9482178 Cylinder liner with an undercut seal trap

A cylinder liner for an engine includes a cylindrical wall having a radially internal surface and a radially external surface opposite the radially internal surface, the cylindrical wall defining a longitudinal axis therethrough, the radially external surface including a sealing surface and an undercut surface adjacent to the sealing surface, the sealing surface at least partly facing away from the longitudinal axis. The undercut surface includes a first surface and a second surface, the first surface at least partly facing the longitudinal axis, and the second surface at least partly facing away from the longitudinal axis.