METHANOL-GASOLINE BLENDS: PERFORMANCE AND EMISSIONS.

Some steady state performance and emissions characteristics of a multicylinder, carburated engine fueled with Indolene and 10, 20, and 30% methanol-Indolene blends over a limited range of operation are presented. Within the precision of the experiments, the blend-leaning effect is found to be in agreement with elementary carburetor theory. With no engine adjustments, the torque is found to decrease with increasing blend levels, the rate of decrease becoming greater at higher blend levels. At torque and engine speed equal to those of gasoline-fueled operation: 1) brake thermal efficiency for the blends is greater than that for gasoline up to about a 30% methanol blend level; 2) NO//x mass emissions are less for the blends, about 60% less for the 30% blend; 3) CO mass emissions increase with increasing blend levels; and 4) intake manifold mixture temperatures are decreased by about 10 degree F. (5. 6 degree C) for each 10% increase in methanol blend level. The monitoring of exhaust-gas oxygen emissions of individual cylinders showed that, for the operating conditions of approximately equals 2000 r. p. m. , approximately equals 16 in. Hg, lean fuel-air ratios, and 10 and 20% methanol blends, the methanol addition had no significant effect on cylinder-to-cylinder fuel-air distribution.