Flat-4

A flat-4 is a four cylinder internal combustion engine where the cylinders are arranged in a flat configuration. This is not a common configuration, but some brands of automobile have favoured such engines and it is a common configuration for smaller aircraft engines such as made by Lycoming. Although they are considered to be superior to "inline-fours" in terms of refinement and vibration, they have largely fallen out of favor because their larger overall dimensions are not suited to modern small cars. The shape of the engine suits it better for rear engine designs, where the low center of gravity is an advantage; in front engine designs the width interferes with the ability of the front wheels to steer.

Related Topics:
Internal combustion engine - Flat configuration - Automobile - Aircraft engine - Lycoming - Rear engine - Center of gravity - Front engine

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The open and exposed design of the engine allows air cooling over water cooling, and in air cooled applications fins are often seen machined into the external cylinder block walls.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~