Car Engines – Notes Page
How does a petrol engine work?
The engine converts gasoline into motion so a car can move. The easiest way to create motion from gasoline is to burn the gasoline inside the engine- therefore has an internal combustion engine.
Conditions found inside car engine
The normal running temperature for a car is between 200-250 degrees. Smog running equipment favours a hot running engine. The proper amount of coolant in an engine will protect it. Thermostats are installed in cars to control temperature making it maintain at about 210 degrees. The temperature can vary though due to different temperatures during different seasons around the year.
The Chemistry behind the burning of fuel in a car
The four-stroke combustion cycle converts gasoline into motion. This is known more commonly as the Otto cycle, in honour of Nikolaus Otto, who invented it in 1867. The four stokes are: intake, compression, combustion and exhaust. A device called a piston is connected to the crankshaft by a connecting rod. As the crankshaft revolves, it resets the cannon. This is the cycle:
1. The piston begins at the top, the intake valve opens and the piston moves downwards allowing the cylinder to fill up with air and gasoline. Only a drop of fuel is needed.
2. The piston moves back up to compress this mixture. This makes the explosion more powerful.
3. When the piston reaches the top of its stroke, the spark plug emits a spark to ignite the gasoline. The gasoline charge in the cylinder explodes.
4. After being driven down, the piston hits the bottom of its stroke, the exhaust valve opens and the exhaust leaves the cylinder to go out the tailpipe.
Essential conditions in a car to produce NO and NO2
Naturally, nitrogen oxides are formed in thunderstorms and forest fires. So the temperature when we combust diesel or gasoline is at about 2000 degrees, this is enough to oxide nitrogen.
N₂(g) + O₂(g) à 2NO(g)
New developments to cars which are also...