الفهرس 
Chapter One 1introductionOnly 14 pages are availabe for public view
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Abstract
This study investigates the effects of using ethanol-gasoline blends on the performance parameters and exhaust characteristics of 4-cylinder, 4-stroke spark ignition engine. The engine used in the study is UAZ (1972) and was equipped with conventional single barrel carburetor and traditional ignition system. The engine has 6.7:1 compression ratio and capacity of 2445 cc. Performance tests were conducted at different engine loads and various speeds 1000-3100 rpm. Experiments were made using four gasoline blends containing 2.5%, 5%, 7.5% and 10% ethanol by volume. The test results were compared with those of gasoline and indicated that ethanol blends enhance the engine torque, power and thermal efficiency. The reductions in exhaust emissions such as carbon monoxide, unburned hydrocarbons and nitrogen oxides were significant along with a noticeable increase in carbon dioxide emission due to better combustion. It was found that 7.5% ethanol gasoline blend is the most suitable fuel as it improves engine performance and reduces exhaust pollutants without any harmful effects to engine parts. Thus, this ethanol ratio is recommended for old technology engines for better air quality and environment.