EFFECT OF GASOLINE - ETHANOL BLENDS ON PERFORMANCE AND EMISSION CHARACTERISTICS OF A SINGLE CYLINDER AIR COOLED MOTOR BIKE SI ENGINE

This paper investigates the effect of using gasoline-ethanol (GE) blends on performance and exhaust emission of a four stroke 150 cc single cylinder air cooled spark ignition (SI) engine, without any modifications. Experiments were conducted at part load and different engine speeds ranging from 3000 to 5000 rpm, without and with catalytic converter. Ethanol content was varied from 5 percentage to 20 percentage by volume and four different blends (E5, E10, E15 and E20) were tested. Fuel consumption, engine speed, air fuel ratio, exhaust gas temperature and exhaust emissions were measured during each experiment. Brake thermal efficiency (eta(b,th)), volumetric efficiency (eta(vol)), brake specific fuel consumption (BSFC) and excess air factor were calculated for each test run. Brake specific fuel consumption, volumetric efficiency and excess air factor increased with ethanol percentage in the blend. Carbon monoxide (CO), hydrocarbon (HC) and oxides of nitrogen (NOx) emissions decreased with blends.