The basic crankcase-scavenged two-stroke suffers from both problems. Typical diesel two-strokes use a separate blower for scavenging, so the combustion air infl

The basic crankcase-scavenged two-stroke suffers from both problems. Typical diesel two-strokes use a separate blower for scavenging, so the combustion air inflow never passes through the crankcase and does not come in contact with the lubricating oil, while the fuel is not injected until after the exhaust is closed. The engine described here can have its shaft and eccentric bearings externally lubricated, but its apex seals, like those of Wankel engines, seem to be in a situation analogous to that of a piston ring. Unlike either of those, however, they are mounted in the stator, not the moving part, and so may be easier to lubricate precisely. https://www.cycleworld.com/2015/04/06/two-stroke-motorcycle-engines-explained-tech-talk-by-kevin-cameron/ https://www.cycleworld.com/2015/04/06/two-stroke-motorcycle-... https://auto.howstuffworks.com/diesel-two-stroke1.htm https://auto.howstuffworks.com/diesel-two-stroke1.htm