Top 10 things you Need to Know About your Car Engine

It's under the hood of every car, truck and SUV, but how many people really know how one works? Do you know a spark plug from a fuel injector?

1. A car engine's job is to convert fuel into motion : There's a lot of heat in a car's engine -- and a lot of exhaust coming out of it -- but these are byproducts of the engine's true purpose. An engine has to use fuel to create motion to move the tires.
2. A car uses a four-stroke engine. The four strokes are intake, compression, ignition and exhaust : In the intake step, a cylinder gets some fuel and air to burn. Then, it compresses the fuel to make the ignition step -- the explosion -- more powerful. In the last step, the cylinder releases its exhaust. This is also known as the Otto cycle.
3. A device that works on the same principle as a car engine is a spud gun : In a both spud gun and a car engine, you ignite a small amount of fuel, releasing a large amount of energy. (And it's equally unwise to get in front of a moving car or a loaded spud gun.)
4. A crankshaft's job in an engine is to change linear motion into rotational motion : When gasoline ignites in a cylinder, the piston moves in a straight line. Your wheels, on the other hand, need to turn. The piston moves a connecting rod, which turns the crankshaft, producing the rotational motion.
5. A car's engine uses a series of small, regular explosions to run. The car doesn't move in stops and starts because the crankshaft along with the flywheel store energy and release it slowly : While a car's muffler does cut down on noise, an engine runs smoothly because the crankshaft along with the flywheel store energy and release it slowly.
6. There are three basic failures that can happen in an engine: bad fuel mix, lack of compression and lack of spark : Lots of things can go wrong under the hood, but the big three in the engine involve fuel, compression and fire.
7. In a car engine's cylinder, valves let fuel in and exhaust out. The camshaft moves these valves : A camshaft is a rotating rod that uses a series of lobes to open and close the valves. Most modern engines have overhead cams -- the camshaft is directly above the valves.
8. A turbocharger is a turbine that compresses the air traveling into the engine : Turbochargers and Superchargers are both air compression systems. They pressurize the air moving into the engine, increasing the engine's power.
9. When you turn the key to a car, the starter motor spins the engine a few revolutions, starting the combustion process : The starter motor has a big job -- it has to overcome friction, cold weather and other factors to get your engine started. If it fails, nothing happens in the engine when you turn the key.
10. Power to run a car's radio, CD player, headlights and windshield wipers comes from the battery : A large battery powers most of a car's accessories. An alternator uses the engine's power to keep the battery charged.

[Source : HowStuffWorks]