Performance of Gasoline-Water Fuel in a Modified SI Engine

Unleaded gasoline containing 5, 10, and 15% of water by volume were tested in a modified spark ignition engine. Engine power output, fuel consumption, efficiency and emissions were measured and reported. Pressure time records of each test run were analyzed to calculate the fuel mass burned fractions. The air cooled single cylinder engine was run at 2000 RPM and at a compression ratio of 7.5.

Generally, the emissions of lower carbon monoxide, oxides of nitrogen and higher unburned hydrocarbons were observed as the volume percent of water in fuel was increased. The power output was increased on the order of 3.8 to 14% when the base fuel containing 5 to 15% water was used. These preliminary performance data conducted with a single cylinder engine suggest that the water-gasoline fuel compares favorably both in mean effective pressure and fuel consumption to that of a gasoline fueled engine.