Westerfield, Z., Totaro, P., Kim, D., and Tian, T., "An Experimental Study of Piston Skirt Roughness and Profiles on Piston Friction Using the Floating Liner Engine," SAE Technical Paper 2016-01-1043, 2016, doi:10.4271/2016-01-1043.
The piston skirt is an important contributor of friction in the piston assembly. This paper discusses friction contributions from various aspects of the piston skirt. A brief study of piston skirt patterns is presented, with little gains being made by patterning the piston skirt coating. Next the roughness of the piston skirt coating is analyzed, and results show that reducing piston skirt roughness can have positive effects on friction reduction. Finally, an introductory study into the profile of the piston skirt is presented, with the outcome being that friction reduction is possible by optimizing the skirt profile.