It is All About Engines: Four Stroke Cycle

Introduction

From the time man set foot on earth, traveling short and long distances had been one of his basic needs. Horse-drawn carriages were used as means of travel and transportation in olden days. The ardent need to travel fast and save time gave rise to the invention of an auto-engine. The invention of a new auto-engine thus marked the dawn of the automotive era in the world. Most cars in Europe began to be built by hand in the early 1900s. As the auto-engine improved, the automobile industry also progressed rapidly.

Although a French engineer Alphonse Beau de Rochas had conceptualized a four-stroke cycle engine in 1862, it was the German engineer Nicolaus August Otto who first invented a complete four-stroke internal combustion engine in 1876 independently. The automobile was further powered by the invention of Otto gasoline engine by Karl Benz of Germany in 1885. This engine was considered more efficient on fuel and clean on burning than the two-stroke cycle engine. Ever since then it had been most commonly used in automobile vehicles like cars, vans and trucks, and in generators for the industrial purposes.

The Scientific Principle & Types of Engines

Have you ever thought what happens when you turn the key in your car? What are the innards of your car engine and how do they work anyway?

An engine is the building block of a car. It is made up of several parts and each has its specific job to perform. First there are crankshafts whose job is to convert reciprocating motion to rotary motion, which causes the wheels to move. There are pistons, which are connected to the crankshaft. The pistons are connected to the crankshaft with a rod cap and the rod bolts.

The internal combustion engines are of different types and sizes, but they all use the same basic principle i.e. combustion of a fuel to produce energy. To give more definition to the principle on which the internal combustion engine works is that the combustion, which takes place in a confined space, produces expanding gasses, which in turn are used to generate power i.e. converting reciprocating motion into rotating motion. These internal combustion engines have been classified as reciprocating or rotary engines. In a reciprocating engine, the most common of the two, combustion takes place in a cylinder that has a piston that goes up and down, while a rotary engine has fewer parts and uses a disk based system. There are also spark ignition and compression ignition engines.

Understanding the Four Stroke Cycle

The cycle in an Internal Combustion Engine most commonly used for automotive and industrial purposes is called the Four Stroke Cycle. In a piston engine this cycle is completed by the several movements (up and down) of the pistons. In a four-stroke engine, each piston moves 4 times (down, up, down, and up) to complete a cycle. The first down-stroke draws air into the cylinder. The first upstroke is the compression stroke. The second down-stroke is the power stroke. The second upstroke exhausts the gases produced by combustion. A four-stroke engine requires exhaust and air-intake valves. The Otto cycle is characterized by four strokes i.e. the back and forth straight movement of a piston inside a cylinder. These four strokes or steps, which a piston takes to complete one combustion cycle in a piston engine is called a four stroke cycle. These strokes are:

1. The Intake Stroke also called Induction Stroke

2. The Compression Stroke

3. The Combustion Stroke, also called Ignition, Power or Expansion Stroke

4. The Exhaust Stroke

The four-stroke cycle begins when the piston is positioned at the uppermost point. During the first intake (downward) stroke of the piston, a combustible mixture of fuel (gasoline) and air is drawn into the cylinder through the inlet valve. The inlet valve then closes. The second upward stroke compresses the fuel-air mixture, already present in the cylinder. This fuel-air mixture is then ignited usually by the spark plugs for a gasoline or Otto cycle engine at approximately the top of the compression stroke. The ignition (explosion) produces expansion in the burning gases that results in forcing the piston downward for the third stroke also called power stroke. The fourth and the final upward stroke, the Exhaust Stroke evacuates the burned or spent (exhaust) gases from the cylinder through the then-open exhaust valve, and finally thrown out in open air through the exhaust pipe. In a piston engine, each piston must move back and forth twice and stop four times to complete the cycle. A piston engine produces one power stroke every other time a piston moves down its cylinder.

Gasoline Engine Versus Diesel Engine

Another German engineer, Rudolph Diesel in 1892, invented the diesel engine. Diesel engine was designed chiefly for heavy-duty work. It is more powerful than gasoline engine and utilizes oil as fuel. Diesel engines are mostly used in heavy machinery, locomotives, ships, and typical automobiles like tractors, large buses, and huge freight trucks for heavy road-building equipment. There are two main types of diesel engines, the four-stroke engine and the two-stroke engine. These types differ according to the number of piston strokes required to complete a cycle of fresh-air intake, air compression, power, and exhaust.

However the Gasoline Engine differs with a Diesel Engine in so far as the ignition part is concerned. The diesel engine is a compression-ignition engine. It compresses the air in the cylinders, causing the temperature of the air to rise. Fuel injected into the hot, compressed air ignites explosively. Therefore the only aspect that makes the diesel engine differ from the gasoline engine is the different ignition cause in each which takes place at the top of compression stroke. In case of diesel engine the air-fuel mixture is ignited by the heat and pressure of the compressed gases, whereas they are ignited by a spark plug in a gasoline or Otto cycle engine.

Craig Willis is an associate staff writer. Upon graduation, he started a career in college papers writing and has been providing quality research paper assistance. His specialty subject is philosophy essays and narrative essays

Written by Car Enthusiast on May 28th, 2007 with no comments.
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Tips In Choosing The Appropriate Car Or Limo Service You Need

With the various limousine services in Toronto, one might get a headache on which to call and avail services from. There might not only be hundreds of limousine services in Toronto so it is more advisable to be wise and prepared in choosing the appropriate limo ride for your needs. Here are some tips that you should remember in deciding what limo service you must avail:

1. Do some background checking or ask friends if they have availed services from your preferred Toronto car service company.

This is a wise action to make before getting services; it is a-must to orient yourselves before getting service. There are a huge variety of car services available within Toronto but only a few are reliable. So, better prevent yourselves from being deceived by those crappy limousine services that will only get into your nerves because of poor service.

2. Ask for free estimates or price consultation.

In some aspects, hiring a car service like an airport limousine service in Toronto might sometimes cost you more than the usual. That’s why in cases such as this it is recommendable to ask for free estimates or price consultation so that you will have the chance to prepare a budget which best fits the kind of limo or car service for you needs. Many Toronto limousine rentals actually provide offers such as this so better call up those kind of car services.

3. Protect your interest.

When getting a Toronto airport limo service, for example, be advised that it is your needs that is what’s important. Do not let yourselves be manipulated on the kind and the type of car or limo ride you need. You are the person who best know what you need so state everything you need from the start and communicate very well with the car or limo service company you are about to avail. There are too many risk that might come and no one for sure wants to experience the hassles of traveling.

4. Comfort and Security at all times.

Two main reasons why many individuals prefer to get a private car or limo service when touring or traveling in different places are comfort and security. Especially if one is traveling along with family or business colleagues, it is more of a guarantee that he or she is traveling with comfort and safety. And to be able to ensure to get comfort and security, finding a reliable and credible company providing services like airport limousine service in Toronto is the key to get hold of one. And lastly:

5. Make sure the company is legal.

One good way in checking if a car service company is legal or not is through inquiring in a transportation office. Through a quick call or surf in the internet can be used as tools in checking if it’s legal or not. Just make sure to provide the correct information about the car service company you are about to get. Also, ask if they are bonded just to serve as your service protection from them.

These tips stated above are only a few from the long list on how to get or select the appropriate and reliable car service company you need to avail. Making sure only takes a little of your time so better do them before getting one. These tips will serve as you shield against deceitful companies that might take advantage of you. Remember, it is better to be safe than to gain bad consequences in return.

Andrew Beene is a web associated with a company providing Toronto car service.

Written by Car Enthusiast on August 21st, 2008 with comments disabled.
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