The Process Of An Internal Combustion Engine

Matt Bagley

English 110

Process Essay

Process of a 4-stroke Internal Combustion Engine

A common phrase that is heard whilst growing up is "curiosity killed the cat". This phrase might be true but; "ingenuity brought the cat back". Having a mindset in which giving up is never an option has plagued most inventors of the modern day, especially a high school drop out named Nikolaus August Otto, born in 1832. Otto was responsible for the development and improvement of the 4-stroke motor that is used today in just about every automobile on the road. Many people drive cars but fail to realize how they work, and don't try to learn about engines because they think it is complex, and not an easy concept to grasp. Air, fuel, spark, and combustion are the premise of an internal combustion engine. A simplistic view on an internal combustion engine is outlined below.

The first step in an internal combustion engine is to acquire all the attributes to create combustion in a chamber. The necessary air flows through the air filter (usually a conical shaped, micro filament, located in either the front right or left of the engine bay). After the air is sucked into the filter it passes through some tubing until it reaches the mass air sensor. The mass air sensor does exactly what it says, senses the amount of air flow and converts it into a signal or number which then is used to determine the amount of fuel to be delivered. The air and fuel must be at a regulated ratio for maximum gas mileage and power efficiency. Next the air goes through the throttle body, this mechanism regulates the amount of air let into the lower half of the engine, and this is attached to the accelerator (gas pedal) by a cable. The further the gas pedal is depressed, the greater amount of air that is let into the engine, which results in faster acceleration.

The air is then sucked into the intake manifold where all the air is divided into the amount of cylinders the car has (4, 6, 8, 12). In the next step the air travels into the combustion chamber (cylinder), where it is mixed with the other components of combustion.

Equally important as the air, is the fuel going into the cylinder. Fuel starts off in the gas tank of the car and then gets pumped into the fuel lines by the fuel pump. The fuel goes through the fuel lines and into the fuel rail. Attached to the fuel rail are electronically controlled injectors (one per cylinder), which are controlled by the mass air sensor. The mass air senor regulates how much fuel is necessary to mix with the air to achieve the ideal air to fuel ratio. The injectors "spray" into the cylinder at synchronized times mixing with air and eventually resulting in combustion.

The final and most important steps of the Internal Combustion Engine are the movements of the pistons. At this point in the process fuel, and air are both present inside the chamber and are combined into a ratio, this is called the air fuel ratio, short AFR. There are four motions of each piston; they are in perfect balance and harmony, much like watching an orchestra perform. These motions (strokes) are detailed as follows:

* On the intake

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