Sexy Opinion: Cars
Most cars use piston engines, with the pistons in various configurations. The Boxer Four is favoured by Subaru, used in many of their cars, with four pistons, two horizantally opposing two. The Prius I drive uses an Inline Four engine, with four pistons vertically aligned. There is also a Straight Six engine, with six pistons aligned, and the classic V-6 and V-8 engines, with six and eight pistons in a V pattern. Expensive muscle cars can even have up to V-12 engines, although they use gas at an extreme rate.
The purpose of the piston is to fulfill the four-stroke method that the engine uses to run: Compression, Combustion, Expansion, and Exhaust. The piston draws gasoline into the chamber and then compresses it, the first stroke. The compressed gas is now extremely volatile, and at the peak of the compression a small spark, from the Spark Plug, ignites the gas, in the second stroke. The burning gas quickly expands, driving the piston downwards in the third stroke. This violent motion causes the piston to rotate the crankshaft, making the tires spin and therefore making the car go. Finally, the piston rises again, pushing out the remnants of the burned gasoline, in the fourth stroke, Exhaust. Thus, in a full cycle, the piston has combusted gasoline and created power for the car while rising up and down twice. That is how a four stroke engine works.
Smaller engines work slightly differently. A chainsaw engine, for example, runs on the same gas that drives a car. However, a chainsaw engine is a two-stroke engine. It combines the first and second strokes of Compression and Combustion, compressing gasoline while igniting it, then expelling it while drawing new gasoline into the chamber. Thus, for every up, the piston creates power, making it more powerful than a four stroke engine. It is not used in cars because while it is more powerful, it is also less efficient and tends to create more waste products than a four-stroke engine which combusts more cleanly than its smaller cousin.
However, there is a third type of engine, much less common than a piston engine. The rotary engine uses no pistons, instead relying on a specially shaped tank, and a specially shaped semi-triangular rotor, called a Wankel Rotor, so named after Mr. Wankel, who came up with the concept. The Wankel Rotor is attached to the crankshaft directly. It spins around in the tank. Due to the shape of the tank and the shape of the rotor, the amount of space between the sides of the rotor and the sides of the tank changes volume. Thus, the rotary engine uses a valve to inject gasoline into a chamber, the volume of which is then lessened due to the rotation of the rotor. This fulfills the first stroke of compression. A strategically placed spark ignites the mixture at maximum compression for the second stroke. The volume of the space expands, for the third stroke. And finally, another strategically placed valve lets out the exhaust for the fourth stroke, at which point the entire process starts all over again. This engine is theoretically more efficient than a piston engine, due to the elimination of the pistons. However, in practice, the engine relies on the integrity of the seals at the edges of the chambers created by the rotor, which sadly tend to fail, making the engine more efficent when it works, but much less efficient when it doesn't.
A hallmark of the Rotary Engine is the peculiar noise it makes; while standard piston engines make the "brrrrrrrr" noise, due to the motion of the pistons, a Rotary Engine makes a more constant humming noise, a sort of "mmmmmmmmmmmm" noise, with the tone rising as the rotation speed of the engine rises.
The Rotary Engine is rarely used today due to its mechanical deficiencies. You can now find it in the Mazda line of cars, specifically the RX- line, of which currently in production you will find the RX-7 and the RX-8. In commercials for rotary cars, Mazda capitalized on the peculiar engine noise which is signature for a rotary engine, leading to the slogan of "mmmmmmm-azda"
Anyway, I saw an rx-8 today while I was driving around redmond and it basically made my day. it was even better than getting my paycheck, honest to god.
The purpose of the piston is to fulfill the four-stroke method that the engine uses to run: Compression, Combustion, Expansion, and Exhaust. The piston draws gasoline into the chamber and then compresses it, the first stroke. The compressed gas is now extremely volatile, and at the peak of the compression a small spark, from the Spark Plug, ignites the gas, in the second stroke. The burning gas quickly expands, driving the piston downwards in the third stroke. This violent motion causes the piston to rotate the crankshaft, making the tires spin and therefore making the car go. Finally, the piston rises again, pushing out the remnants of the burned gasoline, in the fourth stroke, Exhaust. Thus, in a full cycle, the piston has combusted gasoline and created power for the car while rising up and down twice. That is how a four stroke engine works.
Smaller engines work slightly differently. A chainsaw engine, for example, runs on the same gas that drives a car. However, a chainsaw engine is a two-stroke engine. It combines the first and second strokes of Compression and Combustion, compressing gasoline while igniting it, then expelling it while drawing new gasoline into the chamber. Thus, for every up, the piston creates power, making it more powerful than a four stroke engine. It is not used in cars because while it is more powerful, it is also less efficient and tends to create more waste products than a four-stroke engine which combusts more cleanly than its smaller cousin.
However, there is a third type of engine, much less common than a piston engine. The rotary engine uses no pistons, instead relying on a specially shaped tank, and a specially shaped semi-triangular rotor, called a Wankel Rotor, so named after Mr. Wankel, who came up with the concept. The Wankel Rotor is attached to the crankshaft directly. It spins around in the tank. Due to the shape of the tank and the shape of the rotor, the amount of space between the sides of the rotor and the sides of the tank changes volume. Thus, the rotary engine uses a valve to inject gasoline into a chamber, the volume of which is then lessened due to the rotation of the rotor. This fulfills the first stroke of compression. A strategically placed spark ignites the mixture at maximum compression for the second stroke. The volume of the space expands, for the third stroke. And finally, another strategically placed valve lets out the exhaust for the fourth stroke, at which point the entire process starts all over again. This engine is theoretically more efficient than a piston engine, due to the elimination of the pistons. However, in practice, the engine relies on the integrity of the seals at the edges of the chambers created by the rotor, which sadly tend to fail, making the engine more efficent when it works, but much less efficient when it doesn't.
A hallmark of the Rotary Engine is the peculiar noise it makes; while standard piston engines make the "brrrrrrrr" noise, due to the motion of the pistons, a Rotary Engine makes a more constant humming noise, a sort of "mmmmmmmmmmmm" noise, with the tone rising as the rotation speed of the engine rises.
The Rotary Engine is rarely used today due to its mechanical deficiencies. You can now find it in the Mazda line of cars, specifically the RX- line, of which currently in production you will find the RX-7 and the RX-8. In commercials for rotary cars, Mazda capitalized on the peculiar engine noise which is signature for a rotary engine, leading to the slogan of "mmmmmmm-azda"
Anyway, I saw an rx-8 today while I was driving around redmond and it basically made my day. it was even better than getting my paycheck, honest to god.