Some Effects of Exhaust Gas Recirculation Upon Automotive Engine Intake System Deposits and Crankcase Lubricant Performance

With control of oxides of nitrogen from automobile exhaust scheduled for 1971 in California, and expected to be applied nationwide in the future, the recirculation of exhaust gas appears promising as a method of lowering NO_x emissions. This paper discusses work done to evaluate effects of exhaust gas recirculation on intake system cleanliness and crankcase lubricant performance.

Intake system effects were evaluated with respect to the formation of deposits in the carburetor, intake manifold and ports, and intake valve tulips.

Crankcase lubricant performance was evaluated with respect to both low-temperature deposition and high-temperature oxidation and copper lead bearing corrosion characteristics.