The design of piston rings for the small engines in common use in Europe is reviewed and it is shown that optimum ring packs are achieved by careful attention to detail. Ring materials are included and the usefulness of carbidic malleable iron is demonstrated for top ring application.
Details are given of analyses of friction effects of piston rings and the results are applied to interpret the future trend in oil control ring design. The problem of measuring piston ring loads is discussed and a new alternative measurement system is described.