Keeping your cool in your classic car is both good for you and for your engine and transmission. So, understanding classic car fans (mechanical vs electric fans) will help keep your engine running in its proper temperature range. If you are looking to keep you vintage car factory original then sticking with the stock components is key, but some minor modifications can go a long way to getting better cooling performance from your classic car. I have found over the years certain vintage cars’ cooling systems (like the big block Chevrolet Chevelle) may not be adequate to handle the current driving conditions.
This post will cover all the mechanical vs electric fans options available for your ride.
Mechanical Fans
Mechanical fans rely on mechanical energy from the engine to operate properly. There are two main types of mechanical fans: clutch fans and flex fans.
Clutch fans are controlled by a thermostat and utilize a clutch to engage or disengage the fan at a specified engine speed or temperature. However, the fan’s clutch never fully disengages—it keeps always spinning at about 30 percent of the water pump speed. The clutch also limits how fast the fan can spin and only turns the fan at a fraction of the water pump speed, depending on engine speed and temperature.
Select a Clutch Fan for:
- Stock or mildly modified engines
- Best overall cooling ability
- Applications up to 6,000 rpm
Flex fans do not use a clutch and therefore operate at 100 percent of water pump speed, making them more efficient than clutch fans. Considered a step up from clutch fans, these fans are typically lighter than clutch fans and often feature blades that flatten out at higher rpms for greater efficiency.
Select a Flex Fan for:
- Mildly modified engines
- Good cooling with less drag (than clutch fans) at high rpm
- Applications up to 8,000 rpm
- Lightweight design
Mechanical fans, also called belt-driven fans, are an ideal choice for stock or mildly modified street vehicles, but they have some significant performance disadvantages. Mechanical fans cause parasitic horsepower loss because your engine expends a certain amount of power spinning your fan. This translates into power loss at the rear wheels. That is why electric fans are typically the number one choice for more highly modified vehicles.
Electric Fans
As the name suggests, electric fans are powered by your vehicle’s electrical system. Although they will place an additional draw on the electrical system, they are a more efficient alternative to mechanical fans and do not cause the dreaded parasitic horsepower loss.
Here are a few other advantages of electric fans:
- Consistent cooling—they always maintain their airflow
- Reduced water pump wear
- Versatility—they can be mounted in front of or behind the radiator
- Multiple sizes and configurations—they can be found in diameters up to twenty inches and are available with single- and dual-fan setups
- Fitment—some electric fans have thin profiles so they can fit where belt-driven sometimes cannot
- Control—some electric fans have an adjustable thermostat while others allow you to operate your fan from your driver’s seat
Select an Electric Fan for:
- High-horsepower applications
- Maximum power and fuel economy–no parasitic power loss
- Enhanced low-rpm cooling
- Increased water pump life
- Additional auxiliary cooling
With no parasitic power loss and all the great benefits, we mentioned above, electric fans have become the preferred choice for many performance enthusiasts. In a future post, we will show you the keys to choosing the right electric fan for your vehicle.
Fan Shrouds
Whether you pick a mechanic or electrical fan it is important to remember to include a fan shroud to ensure that the air flows properly across the entire radiator. Fan shrouds are passive air-flow improvement devices. They mount behind your radiator and around your fan blades. In this position, they channel airflow directly over your radiator and improve cooling-rates in the process. The fan shroud makes the fan more efficient. Without it, air is deflected off the fan blades in all directions. Without a shroud, the fan only pulls a column of air equal to its surface area. This means the area of the radiator that is not covered by the fan is wasted.
Finally
Remember staying cool and operating in the proper temperature range is the key for optimum car performance. That can be said for both you and your classic car.
