Mechanism of Car Engine
The process of converting gasoline into motion is called internal combustion. An internal combustion engine needs air and fuel to function. These engines are small and controlled explosions to generate the power needed for the movement of a car.
The more efficiently an engine breathes, the more efficiently power is produced. A car weenie creates an explosion in the same way as when you create an explosion in a tiny, enclosed space such as a piston in an engine, a huge amount of energy is released as expanding gas hundreds of times per minute. This energy is harnessed by the engine and is used to propel your car. The following 4 strokes happens to move a car:
Intake:During this cycle, the intake valve opens as the piston moves down. The mixture of air and fuel fills the combustion chamber. The intake valve closes and next cycle begins.
Compression: As this intake valve closes, the piston moves on the upward stroke and compresses the air-fuel mixture into a smaller space. A smaller space, in the sense powerful explosion.
Combustion:The spark plug ignites the air-fuel mixture and causes explosion. The explosion power forces the piston back down. This is called power stroke.
Exhaust:The piston begins its second upward stroke and the exhaust valve opens to release waste gas that was created by the explosion. This gas is moved to the catalytic converter, where it is cleaned and then through muffler before it exits the vehicle through the tailpipe.
The opening and closing of valves is performed by the camshaft. Camshafts are single overhead or double overhead depending on number of valves. The cylinders are arranged inline or V-shaped depending on the number of cylinders. The customers usually speak about compression ratio and displacement. Compression ratio is the ratio between the total volume of the combustion chamber cylinder when the piston is at the bottom of the stroke and when the piston is at the top of the stroke. For example, if the volume of the combustion chamber cylinder when the piston is at the bottom is 10 and when the piston is at top is 1, the compression ratio will be 10:1. Higher compression ratios produces more power, but require more amount of fuel when compared to an engine with low compression ratio.
Engine displacement is the way to describe the internal size of an engine. It is the measurement of the cylinder bore times the length of the stroke, which is multiplied by the total number of cylinders. This is usually expressed in Liters (L) or Cubic Centimeters (CC). For example, a 1.2L 4-cylinder engine has a total displacement of 1.2L by adding together the 4 cylinders of 0.3L each. The same logic is applicable when expressed in terms if CC (For example, 1200 cc engine).
The number of valves in an engine varies. Some engines possess 1 intake and 1 exhaust valve, some have 2 intakes and 1 exhaust valve. Most high performance engines tend to have 2 intakes and 2 exhaust valves. There are various technologies used by car manufacturers to enhance power output, fuel economy and emissions control.