A naturally aspirated engine uses the natural atmospheric pressure and the vacuum created by the piston movement to pull in air. When the pistons fire and draw down into the engine, they pull air after them. The air then mixes with the fuel vapor and burns, creating internal combustion. This is the most common type of engine aspiration.
Internal combustion engines need to have a combination of fuel and air coming into the valves to create the explosions necessary to keep the pistons moving. Whether they're on sports cars or farm tractors, engines suck in fuel and air at different speeds. The mechanism by which this happens is referred to as the aspiration of the engine.
Naturally Aspirated Engines
Turbo or Supercharged Aspiration
Both supercharging and turbocharging create a forced induction in the engine. Air is introduced into the engine by one of the chargers under pressure, rather than simply relying on atmospheric pressure to provide enough air to the engine.
Turbocharged and supercharged engines produce more power than simple naturally aspirated engines because of the additional air flow produced and the additional pressure the chargers create. This is the main reason that the additions are used. However, both a supercharger and a turbocharger are considered additional power sources that are attached to a naturally aspirated engine; they are not different types of engines entirely.
Turbocharged and supercharged engines are more expensive than a simple naturally aspirated engine. The cost encompasses more than the added expense of installing the additional equipment. Forced induction takes a toll on the engine, making parts wear out more quickly. And producing extra power burns more fuel, reducing fuel efficiency.
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