Belt-Driven Radiator Cooling Fans

Belt-driven radiator fans are engine cooling fans driven directly by power from the engine via a pulley or belt from the water pump.

There are two main types of a belt-driven...

Belt-driven radiator fans are engine cooling fans driven directly by power from the engine via a pulley or belt from the water pump.

There are two main types of a belt-driven fan: clutch fans and flex fans.

Clutch Fans

Belt-driven clutch fans attach to a fan clutch. Most of the time, these fans are spinning at some fraction of the water pumps’ speed, but above a certain temperature, the thermostat in the fan clutch fully locks up, and the fan operates at the same speed as the water pump, drawing extra air through the radiator.

Flex Fans

Flex fans don’t have a clutch, so they spin at 100% of the speed of the water...

Belt-driven radiator fans are engine cooling fans driven directly by power from the engine via a pulley or belt from the water pump.

There are two main types of a belt-driven fan: clutch fans and flex fans.

Clutch Fans

Flex Fans

Flex fans don’t have a clutch, so they spin at 100% of the speed of the water pump all the time! Most flex fans also have flexible blades that flatten out at high speeds, reducing the parasitic loss of horsepower.

Belt-driven vs. Electric Cooling Fans

Which is the right fan for your application? Since their speed is tied directly to rpms, mechanical radiator fans are ideal for vehicles that operate at higher revs, like towing vehicles and off-road rigs. They’re also simpler, without sensors, wiring, or electrical draw to worry about.

There are a lot of advantages to switching to an electric fan: they take up less room, they’re more energy efficient, and you can manually deactivate them (a handy feature for off-road vehicles crossing water or mud).

For a complete discussion on the subject of radiator cooling fans, check out this article on our blog.

Top Brands

Summit Racing Equipment has everything you need for anything you drive, and that includes belt-driven fans in a wide variety of sizes and blade counts, plus stock replacement and restoration fans. Shop here for the best brand names in cooling, including Flex-a-lite, Goodmark, Dorman, Perma-Cool, Maradyne, Vintage Air, and many more.