Analysis of Mechanism Intermixing Combustion Products in Engine Oil

Abstract

It is widely known that NO_x emission from an engine plays an important role in the formation of varnish and sludge in engine oil. Therefore, the authors measured the concentrations of nitric and nitrous acid ions in lubricating oil and analyzed the process through which NO_x mixes into the lubricating oil. The latter was found to occur through oil film on the cylinder wall and through crankcase gas, the amount being proportional to the NO_x concentration of nitrous acid ions when the engine temperature drops results in the condensation of water vapor contained in crankcase gas.