I still run hot with electric fans
Water Pumps and Cooling
When someone swaps to electric fans and the engine still creeps up in temperature, the fans are usually simply not moving enough air.
Overview
Short Answer
In most cases, if the electric fans are not getting the job done, they have too low a CFM rating. Anything less than 3,500 CFM per fan will likely result in overheating issues.
Check the rating before you change anything else
Electric fan advertising is optimistic, and a fan that looks substantial can move far less air than a factory clutch fan did. Before you start changing radiators, thermostats or water pumps, find the actual CFM rating of the fans you installed.
Our rule of thumb is simple. Under 3,500 CFM per fan and you should expect to run hot on most V8 builds, whatever else is right about the cooling system.
If you are short on room for a bigger radiator
A common bind is wanting a thicker radiator but having no clearance for it up front. On big block Chevy builds, a short water pump system moves the whole accessory drive rearward and buys back space:
If it started right after a new kit went on
Check how fast the water pump is actually turning before you spend money on fans. Underdrive pulleys slow the pump down considerably, and a belt that slips lets the pump slip with it. It is also worth confirming the thermostat is installed correctly and that the cooling system was fully bled, because trapped air causes temperature spikes. Our article on overheating after installing a serpentine kit walks through all of it.
What to tell us
If you write in about a cooling problem, include your radiator, fan make and CFM rating, thermostat rating, whether you run a shroud, and your engine combination. Without those we are guessing.
Still need help? Our tech support team can get you pointed in the right direction.
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