Abstract: A method for estimating at least one ring-related parameter related to at least one piston ring may include estimating a bore distortion of a cylinder bore. The bore distortion may include a plurality of bore distortions corresponding to a plurality of respective piston locations within the cylinder bore. The method may also include receiving the bore distortion in a ring performance model configured to dynamically estimate a plurality of ring-related parameters associated with combustion in the cylinder bore during operation of the internal combustion engine. The ring performance model may be configured to receive a static data signal indicative of static parameters and a dynamic data signal indicative of dynamic parameters related to operation of the internal combustion engine. The ring performance model may be configured to estimate at least one ring-related parameter related to at least one piston ring during operation of the internal combustion engine.

Abstract: A method for estimating at least one ring-related parameter related to at least one piston ring may include estimating a bore distortion of a cylinder bore. The bore distortion may include a plurality of bore distortions corresponding to a plurality of respective piston locations within the cylinder bore. The method may also include receiving the bore distortion in a ring performance model configured to dynamically estimate a plurality of ring-related parameters associated with combustion in the cylinder bore during operation of the internal combustion engine. The ring performance model may be configured to receive a static data signal indicative of static parameters and a dynamic data signal indicative of dynamic parameters related to operation of the internal combustion engine. The ring performance model may be configured to estimate at least one ring-related parameter related to at least one piston ring during operation of the internal combustion engine.

Abstract: A piston for an internal combustion engine has an upper crown with a top and a bottom surface, and a lower crown with a top and a bottom surface. The upper crown and the lower crown are fixedly attached to each other using welds, with the bottom surface of the upper crown and the top surface of the lower crown forming a mating surface. The piston also has at least one centrally located air gap formed on the mating surface. The air gap is sealed to prevent substantial airflow into or out of the air gap.

Abstract: A piston for an internal combustion engine has an upper crown with a top and a bottom surface, and a lower crown with a top and a bottom surface. The upper crown and the lower crown are fixedly attached to each other using welds, with the bottom surface of the upper crown and the top surface of the lower crown forming a mating surface. The piston also has at least one centrally located air gap formed on the mating surface. The air gap is sealed to prevent substantial airflow into or out of the air gap.