Technical Paper
Concentrations of Nitrogen Oxides in Crankcase Gases
1976-02-01
760563
The concentrations of oxides of nitrogen (NOx = NO + NO2) in engine crankcases interest lubricant technologists because NOx reactions with fuel and lubricant components are partially responsible for engine deposits and oil deterioration. To provide information hitherto unavailable in the literature, concentrations of NOx and NO2 were measured in the crankcase gas of a multi-cylinder engine operated at a variety of steady-state conditions. The concentrations of NOx and NO2 measured in the crankcase gas followed the same trends with changes in engine operating variables as the concentrations of NOx and NO2 in the exhaust gas. Specifically, increasing intake manifold pressure, spark advance, and compression ratio, generally increased the concentrations of NOx and NO2. Increasing the percent exhaust gas recirculation, however, decreased NOx and NO2 concentrations.