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Science project idea on the working of the gas engine.
Gas Engine Science Project Idea 
The working of the gas engine.  The gas engine has become of great importance not only because of its economy of fuel, but also because of its ease of operation and lightness.Its combination of great power with light weight has made possible the marvelous development of the airplane and automobile.You will be interested in looking into the working of the  gasoline engine as shown in the motor of an automobile.
The successive positions of the piston may be seen from the examination of the accompanying diagrams. First or suction stroke The mixture of air and gasoline passes into the cylinder.Note that the gasoline is not a liquid but a gas, having become vaporized in the carburetor. Second or compression stroke The mixture of air and gas is compressed. Third or power stroke At the end of the compression stroke, the air and gas mixture is exploded by the spark that passes between the two wires, and the piston is forced downward.
Fourth or exhaust stroke  The piston passes back into the cylinder, forcing out the gases which remain after the explosion.The piston is now in position for the beginning of the suction stroke again.Note the position of the intake and exhaust valves at each stroke.
Of the four strokes of the piston, how many are power strokes? As four strokes are necessary to complete the cycle (circle), an engine of this kind is known as a four-stroke cycle engine. The power developed by the explosion in the cylinder is applied to moving the automobile by having the piston rods connected with the crank shaft, which is made to rotate by the up-and-down stroke of the piston rod.By a series of cogs called gears, the power is applied to the rear axle, causing the wheels to turn. Need for a flywheel What causes the engine to run between the times of the power strokes?A one-cylinder engine would not run if a heavy flywheel were  not attached to a continuation of the crank shaft.The power stroke sets in motion the flywheel which by its rotation carries the crank shaft around until the piston is in position for the next power stroke. Advantage of a number of cylinders The first automobiles made were equipped with one-cylinder gasoline engines, but now they are fitted with engines having a number of cylinders; four, six, eight, twelve, and in airplane engines an even larger number.By the use of a number of cylinders, the power is more continuously applied, with the result that the engine runs much more steadily. Explain how a four-cylinder, four-cycle engine would have four times as many power strokes as a one-cylinder engine. How the spark is furnished When an engine is started, the spark is usually furnished by an electric current generated by a battery.However, after the engine has  started, it generates its own electricity by means of a magneto.This explains how an automobile may be started without the use of batteries by allowing it to coast downhill or by turning the crank rod a number of times, sometimes called "spinning on the magneto."It is evident that the magneto must be equipped with an apparatus for timing the spark, for if the explosion occurs a fraction of a second too soon or too late, the results will be unsatisfactory. Explain why the engine must be started by hand (by cranking) or by a self-starting apparatus. Cooling the engine As the cylinders become very hot during the explosions, they must be cooled.This is usually done by surrounding the cylinders with a space filled with water.The water circulates through the radiator where it is cooled by air drawn through the meshes of the radiator by a fan.Some automobiles are cooled by air without the assistance of water. As all parts must slide easily in order to avoid loss of power and overheating by friction, there must be a system by which the engine automatically oils itself.
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