For high rpm use, flex fans are considered an upgrade over clutch fans. They can be a good choice for modified vehicles turning 6,000 – 8,000 rpm. Advantages include: They move more air for better cooling.
What does a flex fan do?
Flex fans use a stainless steel frame and blades of either plastic or steel riveted to the frame. By design, their blades flatten out at a preset RPM to reduce power-robbing drag on the engine. Drag is defined as the power necessary to turn the fan.
How much horsepower does a flex fan take?
Registered. I’m sure a flex fan takes 5-10 horse but some large electric fans can pull 30 amps. Might be a horse or two just to make that. For the money you can’t go wrong with a standard thermal coupled mechanical fan and a proper shroud.
What is better flex fan or electric fans?
Flex fans don’t 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.
Do electric fans cool better than mechanical?
All fans consume energy to spin. Belt-driven fans use mechanical energy directly from the engine. Electric fans rely on electric energy from the battery and charging system. But in cooling, what makes a good fan is optimum airflow for cooling with minimum energy consumption (for maximum engine power and fuel economy).
How much power does a clutch fan Rob?
If the fan is required the clutch kicks in and the fan uses maybe one or two HP to turn it. If you have electric fans, your engine must drive the alternator to provide the electric power for them. This might add up to one or two HP also.
Do electric fans save HP?
In a normal pickup situation, even in high ambient temperatures, the electric fan system will only draw a maximum of about 5 horsepower from the engine. This significant savings improves fuel economy, and, in turn, reduces emissions while improving vehicle performance.
What is the advantage of a clutch fan?
A fan clutch is a thermostatic engine cooling fan that can freewheel at low temperatures when cooling is not needed, allowing the engine to warm up faster, relieving unnecessary load on the engine. As temperatures increase, the clutch engages so that the fan is driven by engine power and moves air to cool the engine.
Do I need a clutch fan?
The Truck Could Overheat
The sole purpose of your engine’s fan system is to cool it down, and without the fan clutch activating, the fan itself cannot turn and keep your engine at the proper temperature for peak performance.
What is the difference between a thermal and non thermal fan clutch?
A non-thermal fan clutch is nothing more than a thermal fan clutch always partly engaged. It provides adequate cooling when needed, however, it does not save you money by disengaging (operating at a lower RPM) when additional cooling is not needed.
What is a viscous fan?
Viscous fan couplings are used on vehicles (cars and trucks) with inline engine positions, mainly rear wheel drives. These fans are needed at slow speeds and while idling. A faulty fan can cause an engine to overheat while idling or in heavy traffic, or poor mileage and loss of horse power.
How does a viscous fan clutch work?
How Does a Viscous Fan Drive Work? In a viscous drive, the main shaft turns at RPM proportional to the engine speed, while the drive housing attached to the engine fan maintains a separate speed, set by the electronic engine control module. In other words: The fan clutch speed is independent from the engine’s RPM.
Do Flex fans wear out?
While the factory clutch fan assembly on the Toyota engine is ok for everyday driving, it is also heavy and the Flex Fan Dual Electric Fan clutch will eventually wear out and become a burden to the motor. Clutch fans also take horsepower to turn once they lock up. There are two very good replacement options available.
Is a cooling fan the same as a radiator fan?
The cooling fan is also known as a radiator fan because it’s mounted directly to the radiator in some engine layout. Typically, the fan is positioned between the radiator and engine as it draws heat to the atmosphere. In front-wheel cars, the cooling fan used is an electrical component powered by the battery.
What are the different types of fans and how do they operate?
How many types of fans are available? There are two main types of exhaust fans: Axial Fans: These fans look like propellers and draw air straight through the fan. Centrifugal fans: These fans look like “squirrel cages” that draw air into the centre of the fan and exhaust it at a 90-degree angle.
How big of an electric fan do I need?
As a general rule of thumb, follow these minimum cubic feet per minute (cfm) ratings when using an electric fan as the primary cooling source on a basic engine: 1,250 cfm for a 4-cylinder. 2,000 cfm for a 6-cylinder. 2,500 cfm for a 8-cylinder.
Do electric fans have a clutch?
Fan Clutches are ‘fluid’ coupling devices that provide air flow through the radiator by using the water pump shaft to power the fan blade. When the pump is cool or at normal operating temperature, the fan clutch will partially disengage.
How does a hydraulic cooling fan work?
The flow divider valve, the steering system and the hydraulic fan drive system function as if each system receives oil flow from a dedicated pump. The fan motor drives a fan to cool the charge air and engine coolant. The more oil that passes through the motor, the faster the fan speed.
