The Basic Idea
If you have read How Car Engines Work, then you are familiar with the concept behind the four-stroke engine. Car engines arrange pistons in three typical patterns, as shown here:
 (Click on image to see animation) Inline - The cylinders are arranged in a line in a single bank. |
 (Click on image to see animation) V - The cylinders are arranged in two banks set at an angle to one another. |
 (Click on image to see animation) Flat - The cylinders are arranged in two banks on opposite sides of the engine. |
Each different configuration has different smoothness, manufacturing cost and shape characteristics that make it more suitable for certain vehicles.
A radial engine is yet another configuration for the pistons, as we will see in the next section.
