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diesel engine Emission
gasoline engine Device
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A wide range of energy-conversion systems has been used experimentally and in automotive production These include electric, steam, solar, turbine, rotary, and a variety of piston-type internal combustion engines The most successful for automobiles has been the reciprocating piston internal-combustion engine, operating on four-stroke cycle, while diesel engines are widely used for lorries and buses. The gasoline engine wa originally selected for automobiles because it could operate more flexible over a wide range of speeds, am power developed for a given weight engine was reasonable; it could be available, moderately priced fuel gasoline model. Reliability, compact size, and range of operations later became important factors.
There has been an ongoing reassessment of these priorities with new emphasis on the pollution-producing characteristics of automotive power system. This has created new interest in alternate power sources am internal-combustion engine refinements that were not economically feasible in prior years. Although a fev limited-production batteries powered electric vehicles have appeared from time to time, they have not proved to be competitive owing costs and operating characteristics. The gasoline engine, with new emission-contro devices to improve emission performance, has not yet been challenged significantly.
In the late 1940s a trend began to increase engine horse-power, particularly in American models. Design changes incorporated all known methods of raising engine capacity, including increasing the pressure in the cylinders to improve efficiency, increasing the size of the engine and increasing the speed at brought a return to smaller engines, four- and six-cylinder designs rated as low as 80 horsepower.
European automobile engines were of a much wider variety, ranging from 1 to 12 cylinders, wit corresponding differences in overall size, weight, piston displacement, and horsepower ratings from 19 t 120.
Fill in spaces with the appropriate word or phrase.
1. A wide range of energy-conversion systems have been used in automotive production including a variet of piston-type ... .2. The reciprocating-piston internal-combustion engine proved to be .... 3. ...
and range of operations later became important factors . 4. In the late 1940s a trend began to increase ....
11. Are the following statements true or false?
1. European engines were of usual variety. 2. As s gasoline engine could operate more flexibly over a wide range of speeds, it was selected for automobiles. 3, The return to smaller engines brought the advent of smaller cars. 4. All known methods of raising engine capacity were incorporated in these design changes.
Date: 2015-12-24; view: 488