Your engine has to keep its cool to continue working correctly and to avoid damage. If you own a modern car, chances are pretty good that it uses a water-cooled system. Some classics from the past relied on an air-cooled engine to keep things in proper working order.
What a water-cooled engine looks like
The engine actually uses a combination of water and antifreeze or coolant to maintain the proper working temperature. The radiator holds the mixture and the water pump forces it to move through the engine in channels. The water mixture absorbs some of the heat from the cylinder head and engine block and goes back into the radiator to cool off and start the process all over.
What an air-cooled engine looks like
Older vehicles often used this type of engine and you may see it today in certain applications. You won’t see a radiator or water pump in an air-cooled engine. Instead, you have cooling fins that are attached to the engine and extend outward to move the heat away. Fans will run to keep the cool air moving. Ducts through the engine allow the air to get in more places. The cylinders also face each other in an air-cooling system, which allows more air to flow than with the traditional design in water-cooled engines where they are aligned together.
While you won’t see the air-cooled engines on most vehicles today, you might want to know how one works if you’re considering buying a classic. You will also find these engines on motorcycles and aircraft.
This article originally appeared on YourMechanic.com as What Is the Difference Between a Water-Cooled Engine and an Air-Cooled Engine? and was authored by Joyce Morse.