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Basic Engine Parts

The core of the engine is the cylinder, with the piston moving up and down inside the cylinder. Most cars have more than one cylinder (four, six and eight cylinders are common). In a multi-cylinder engine, the cylinders usually are arranged in one of two ways: inline or V, as shown in the following figures.

Inline 4 engine diagram
Inline - The cylinders are arranged in a line in a single bank.
V6 Engine diagram
V - The cylinders are arranged in two banks set at an angle to one another.

Let's look at some key engine parts in more detail.

Jeep Engine
Jeep Engine
Spark plug
The spark plug supplies the spark that ignites the air/fuel mixture so that combustion can occur. The spark must happen at just the right moment for things to work properly.
The intake and exhaust valves open at the proper time to let in air and fuel and to let out exhaust. Note that both valves are closed during compression and combustion so that the combustion chamber is sealed. The Timing Belt does the job of moving these valves.
A piston is a cylindrical piece of metal that moves up and down inside the cylinder.
Piston rings
Piston rings provide a sliding seal between the outer edge of the piston and the inner edge of the cylinder. The rings serve two purposes: Most cars that “burn oil” and have to have a quart added every 1,000 miles are burning it because the engine is old and the rings no longer seal things properly.
Connecting rod
The connecting rod connects the piston to the crankshaft. It can rotate at both ends so that its angle can change as the piston moves and the crankshaft rotates.
The crankshaft turns the piston's up and down motion into circular motion that can turn the wheels.

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