Study of the lubrication mechanism of two-stroke engine oils using a disc machine

A technique has been developed to evaluate scuffing characteristics of two-stroke engine oils on a high speed disc machine. This paper deals with the lubrication mechanisms involved in the test adopted. The influence of h/σ, surface conformity and boundary characteristics of lubricants were examined. It was observed that the lubrication mode changed from hydrodynamic to mixed to boundary conditions leading to eventual failure. This situation is similar to that observed in two-stroke piston tightening tests where the lubrication mode changes from hydrodynamic to mixed lubrication as the temperature increases.