What is the purpose of a fan clutch?
While many see clutch-style mechanical cooling fans as obsolete when compared to modern electrics, the fact is that these bits of classic 1970s tech still have a place in today’s automotive scene.PurposeA clutch fan is designed to keep the engine’s water-pump-mounted mechanical fan from turning when it’s not needed to cool the engine.FunctionA clutch fan contains viscous silicone fluid that constantly recycles through the clutch when the fluid valve is open. Engine heat causes a thermostatic spring (a spring that expands with heat) to expand, closing the valve and locking the center shaft to the fan blades with hydraulic pressure.Economy BenefitsA cooling fan always locked to the engine constantly draws horsepower, which negatively impacts fuel economy.Power BenefitsA clutch fan allows the engine to run at its full potential when cool, which is a boon to power and acceleration.ComparisonA clutch type cooling fan has about the same impact on power as an electric cooling fan (which requi
