ENGINE PISTON

A piston (100) for an internal combustion engine includes a piston (100) body forming a crown portion (102) and a skirt portion (104). The skirt portion (104) includes a bore that receives a pin for connecting the piston (100) to a connecting rod, and the crown portion (102) forms a bowl (110) surrounded by a flat crown surface (112) having an annular shape and disposed along a plane. The bowl (110) and the flat crown surface (112) meet along a circular edge surrounding a rim (212) of the bowl (110). The piston (100) further includes an annular protrusion (216) disposed within the bowl (110) adjacent the rim (212). The annular protrusion (216) has a generally convex shape in cross section created by an upper, inwardly extending surface (220) and a lower, inwardly extending surface (220) that meet along a convex apex (306). The piston (100) further includes an airfoil surface (200) formed in the flat crown surface (112). The airfoil surface (200) has a convex shape and extends annularly around the rim (212) of the bowl (110).