A piston for a direct injection engine is provided, the piston having a bowl at an upper end, the bowl forming a portion of a combustion chamber. The bowl includes an inner surface that defines a volume configured to receive a fuel-air mixture, the inner surface of the bowl including at least one surface feature that forms at least one edge portion as a target for the fuel spray, the edge portion defined by two or more surface portions. The surface feature may protrude from the inner surface of the bowl or may be recessed into the inner surface. Such surface features may reduce soot and improve fuel-air mixing.
Rainer J. Rothbauer; Charles E. Roberts Jr.