The purpose of the Technical Description Assignment was to write about an object or process that we had an interest in. The first draft was rough, but feedback allowed the final draft to be more polished.

 

 

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Final Draft

 

Shadman Rahman

Professor Moser

English 21007

2/25/20

Basics of the Modern Engine

The creation of the combustion engine has allowed mankind to develop to the way it is today. Car engines have reduced time in transportation, eases shipping, however, it has led to climate change in a destructive manner, due to it producing greenhouse gases. Here, we can learn how an engine functions and also the parts that allow it to properly function.

How it works:

Many steps are taken so the engine can work. To describe each step, it is known as a cycle. There are four cycles that are put together to make the engine properly function. It is in the order of intake, compression, power, and exhaust.

Intake Cycle:

The intake cycle is in laymen’s terms, is how the engine breathes. Air enters through a passage from the engine and it mainly consists of four to five pipes that merge to one. This is known as the intake manifold and is depicted as:

As the air flows towards the engine from the intake manifold. Fuel is then sprayed by the end of the intake manifold, and gets mixed with the air. In most cases, the fuel is gasoline, but in a majority of engines, diesel is used. In this case, it is gasoline. The gasoline gets sprayed by something called a fuel injector. As the name suggests, the fuel injector injects fuel into the engine. The fuel injector is depicted as:        These are the basics of the intake cycle.

 Compression Cycle:

The compression cycle happens in the engine block. This is where the process of compressing the air and fuel takes place takes place and where the main parts of the engine are located, such as the piston, connecting rod, and crankshaft.  With everything put together it looks like this:

In the engine block they air and fuel mixture gets forced in by vacuum of the engine ( As the engine runs, it naturally creates vacuum pressure). The compression cycle begins when the piston gets pushed up and compresses the mixture, allowing it to ignite easier. This then follows the  power cycle.

Power Cycle:

The power cycle begins where the compression cycle ends. It then ignites the compressed mixture with the sparkplug, this is known as combustion. The sparkplug makes an electrical spark. After the mixture ignites, the energy pushes down the piston making the other piston push up, and continues the cycle. The crankshaft allows the pattern to continue. As the crankshaft rotates it makes the piston move in a linear motion going up and down. As the pistons move up and down, the power cycle continues and allows the engine to run.

Exhaust cycle:

This begins when the exhaust valve opens up and lets out the burned mixture, in some engines the exhaust is mixed back into the intake mixture. This burnt mixture exits the engine through an exhaust pipe that leads to the rear of the vehicle.

 

To have an engine run properly, it needs to be timed properly. These cycles have to be timed precisely or else damage can occur. In most modern engines, the engine is timed by the engine computer and that handles most of the tasks. The computer  advances or retards the timing, this means it slows the engine down ( retard ), or speeds it up ( advance).  The power cycle relies on the vehicle battery and alternator. The main purpose of the battery is just to start the engine, after the engine is running, the alternator runs as the engine runs. The alternator acts as a generator for the engine.

 

 

The basic engine and parts cycles are depicted in his diagram:

 

 

 

Work Cited

    Engine Process. Encyclopedia Brittannica, https://www.google.com/url?sa=i&url=https://www.britannica.com/technology/diesel-engine&psig=AOvVaw2tdB71LBmKhwM1v0bFYwPa&ust=1582081784901000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCJCZ-JeR2ucCFQAAAAAdAAAAABAE.

 

“Engine Parts.” Pinterest, https://www.pinterest.com/pin/70016969190763125/.

 

“Intake.” Autoricambi.us, https://autoricambi.us/single-plane-intake-manifold/.

 

“Fuel Injector.” Quadratec.com, https://www.quadratec.com/products/51306_1023.htm.

 

“Engine Block.” Inductionperformance.com, https://www.inductionperformance.com/products/induction-performance-stage-1-2jz-short-block.

 

“Alternator.” Samarins.com, https://www.samarins.com/glossary/img/alternator-large.jpg.