Abstract: A piston having a defined sized outer diameter. The piston has a defined, coated surface which determines the specific outer diameter of such surface which is the contact surface with the cylinder of an internal combustion engine. The defined surfaces are either the skirt or the top land ring, or both.

Abstract: A method and apparatus for sizing a piston to a defined size outer diameter surface, which is the contact surface with the cylinder of an internal combustion engine. The apparatus method involves first measuring each piston, then calculating the amount of coating required to achieve the desired diameter for each individual piston or range of pistons and then applying a precise coating in either one or more coats preferably by using a rotary pad printing technique to produce the precise film thickness, thus narrowing the diameter range of the group of pistons.

Abstract: A piston with piston skirt dry film lubricant coat applied by the transfer pad process to lessen the stresses associated with reciprocating engine parts and method for applying such a coat to the skirt of a piston. Wetted dry film lubricants are diluted with volatile solvents to create a wetted dry film lubricant of liquid consistency in order to make the dry film lubricants adaptable to the transfer pad coating process. Application of the wetted dry film lubricant to the piston by the transfer pad coating process provides for the precise and discriminant application of dry film lubricants to piston skirts thereby providing a less costly coated piston by avoiding the time-consuming task of masking the pistons prior to application of a wetted dry film lubricant by the currently used spray method and eliminating the waste and pollution problems associated with the spray method.