A 25-75 blend (v/v) of alkali-refined sunflower oil and diesel fuel, a 25-75 blend (v/v) of high oleic safflower oil and diesel fuel, a non-ionic sunflower oil-aqueous ethanol microemulsion, and a methyl ester of sunflower oil were evaluated as fuels in a direct injected, turbocharged, intercooled, 4-cylinder Allis-Chalmers diesel engine during a 200-hour EMA cycle laboratory screening endurance test. Engine performance on Phillips 2-D reference fuel served as baseline for the experimental fuels.
This investigation employed an analysis of variance to compare CRC carbon and lacquer ratings and wear of engine parts for all tested fuels.
The paper deals with carbon and lacquer formation and its effect on long-term engine performance as experienced during the operation with the alternate fuels. Significantly heavier deposits than for the diesel fuel were observed for the microemulsion and 25-75 sunflower oil blend, particularly on the exhaust and intake valve stems, on the piston lands, and in the piston grooves.
In all tests engine wear was not significant. The final dimensions of the measured elements did not exceed the manufacturer's initial parts specifications.