Abstract: A piston includes a swirl pocket that extends radially from the radially outer lip portion to a lower axial extremity spaced away from the radially outer lip portion a first axial distance. A convex arcuate surface extends downwardly and inwardly from the radially outer lip portion, a concave arcuate surface extends to the lower axial extremity from the convex arcuate surface, and a conical portion extends upwardly and inwardly from the concave arcuate surface to an apex that is spaced a second axial distance from the radially outer lip portion that is less than the first axial distance.

Abstract: A piston includes a swirl pocket that extends radially from the radially outer lip portion to a lower axial extremity spaced away from the radially outer lip portion a first axial distance. A convex arcuate surface extends downwardly and inwardly from the radially outer lip portion, a concave arcuate surface extends to the lower axial extremity from the convex arcuate surface, and a conical portion extends upwardly and inwardly from the concave arcuate surface to an apex that is spaced a second axial distance from the radially outer lip portion that is less than the first axial distance.

Abstract: An anti-polishing ring includes a ring body defining an axis of revolution, and a radial direction that is perpendicular to the axis of revolution, and a circumferential direction about the axis of revolution. The ring body includes an outer circumferential surface, a bottom surface, a top surface, and an inner circumferential surface. The inner circumferential surface defines an inner diameter, the ring body defines a radial thickness measured from the inner circumferential surface to the outer circumferential surface, and a ratio of the radial thickness to the inner diameter ranges from 0.015 to 0.020.

Abstract: Operating an internal combustion engine includes conveying fuel of spray plumes of directly injected fuel out of a swirl pocket in a combustion bowl in a piston, and impinging the fuel upon an anti-sooting ramp transitioning between a radially inner shelf surface of the combustion bowl and a radially outer squish surface of the piston. The shelf surface is spaced an axial distance (FA) from a plane defined by the squish surface that is from 1% to 2% of an outer diameter (OD) dimension of the piston. Impinging the fuel upon the anti-sooting ramp directs the fuel upwardly from the squish surface to limit wall-wetting in the combustion cylinder.