Performance of a Spark Ignition Engine Fueled with Methanol or Methanol-Gasoline Blends

Engine torque and specific energy consumption of an automotive engine were studied under steady state condition using gasoline, methanol gasoline blends and straight methanol as fuel. At first the engine was run without any modification. Next the diameters of metering orifices in carburetor were modified to give the same excess air factor regardless of fuel type under each fixed engine operating condition. Finally the engine was run with 15% mixture methanol in gasoline by volume using the carburetor modified to have approximately 10% larger fuel flow area than the production carburetor. From the results of this study the effects of using methanol on engine torque and specific energy consumption can be explained on the basis of change in stoichiometry caused by the use of methanol.