Abstract: A piston includes a plurality of pockets formed in the piston top face and opening through the piston sidewall. An arcuate relief is associated with each pocket and formed in the sidewall to overlap the pocket opening. The depth of the relief is relatively greater than the depth of the pocket.

Abstract: An improved oil damped piston for use in internal combustion engines, pumps, compressors, or the like. The piston includes a generally cylindrical piston body having a crown and a depending skirt. A pair of spaced bands of polytetrafluoroethylene are carried by the skirt and each has a surface radially outwardly of the skirt. Each of the band surfaces includes a configuration defining a pumping surface for directing lubricant on a cylinder wall into the space between the band. The oil in the space damps side to side movement of the piston within its cylinder.