Essay, Research Paper
The gasoline engine has changed the world forever. When Karl Benz improved the internal combustion engine and put it into an automobile he started something that to this day is still being improved on. The Germans are known for there fine luxury vehicles, but it’s America that wants bigger and better. Americans have raced their automobiles from the time before Henry Ford rolled his first car of the assembly line. The basic principle of the gasoline engine is the fuel is mixed with air in the carburetor, then flows though an intake manifold, from there the air/fuel mixture passes through a valve. When the fuel enters into the combustion chamber the valve closes. The fuel is then compressed by the piston. It is then ignited by an electronic spark. After ignition the burring gasses force the piston downward in the cylinder. Connected to the piston is a rod, usually iron or aluminum, that connects to a crankshaft. The crankshaft changes the vertical motion of the piston into a horizontal rotation. In larger engines the crankshaft has a sprocket on the end which a chain or belt connects to another larger sprocket. This larger sprocket is connected to the camshaft. The camshaft spins from the momentum of the crankshaft. The camshaft has lobes on it that push lifters, that in turn push pushrods that push upward on the rocker arm. The rocker is fixed in a slot that restricts its movement to up and down. On the side opposite the pushrod is the valvestem. This is part of the valve. There is a spring attached to the end of the valve stem that forces the rocker back in place. The upward push of the pushrod forces the valve to open. The crankshaft spins back around forcing the piston back upward. As the piston rises another valve opens, this is called the exhaust valve, the gases then exit the combustion chamber. There have been many improvements to the gas engine, but the basic idea still holds true. Throughout the world people have modified engine to get more performance out of them, but in the United States the number of different racing competitions is far greater than anywhere else. This makes performance modifications much more in demand. Most race enthusiast spend hundreds of thousands of dollars building cars that go faster than the competition. Most professional racers that race in organized races must follow rules that restrict their engines capabilities. When modifying an engine for racing you must follow these guidelines for the type of racing you wish to do. The fastest way to increase power is to select a camshaft with the right degree on the lobes for the performance you wish to get. The next step would be to increase the amount of fuel your engine gets. This is accomplished by replacing the carburetor (on newer vehicles this is done by replacing the injectors). While adding a new carburetor a new intake manifold should be installed. On serious drag racing cars a dual carburetor setup is used. The next step in building the engine is the heads. The heads are the top of the combustion chamber, they also house the valves. The heads should be replaced (or put on a new engine block) with aluminum heads. The aluminum heads are lighter weight. The pistons should be high quality and of the right measurement to avoid piston slap or detonation. The connecting rods should be of similar quality. A good oiling system is necessary to keep the friction as low as possible. High quality valves, pushrods, valve spring, lifters and rocker arms should be obtained. The pushrod length should be chosen to properly match the engine size. When choosing the valve and camshaft system a “roller” system should be considered. The roller system reduces friction, which in turn increases the engines performance. In conclusion the racing industry has led to the development of smaller more efficient high performance engines. These developments can be seen in the four cylinder cars that people drive on our road everyday. The newer engines are capable of producing great amounts of horse power. In a few years engineers may have developed even better motor than the ones we have today.