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Q: Why convert from a belt driven fan to an electric fan? Q: How do I convert my engine from a belt driven fan to an electric fan? Q: What is the difference between a "pusher" and a "puller" fan? Q: How do I change the fan from a puller to a pusher? Q: How do I mount the electric fan?
Q: Why convert from a belt driven fan to an electric fan? A: At low vehicle speeds, when airflow through the radiator is crucial, the belt driven fan slows down with the engine RPM, decreasing airflow. Electric fans maintain their speed regardless of engine RPM, providing maximum airflow and better cooling than a belt driven fan. A belt driven fan takes horsepower from the engine to turn, resulting in less performance and lower gas mileage. Converting to an electric fan restores this power to the engine for better performance and increased fuel economy. Q: How do I convert my engine from a belt driven fan to an electric fan? A: First you need to determine your engine’s CFM (cubic feet per minute) requirements. Four cylinder engines need about 1,200 CFM; six cylinder engines need around 1,600 CFM; small block V-8s need 2200 CFM and big block V-8s require approximately 3400 CFM. These CFM requirements are based on gas powered passenger cars and light trucks, not used for towing, in regular driving conditions. Engines that have been modified, raising the operating temperature, will require more CFM than stock engines. Examples include raising the compression ratio, installing a turbocharger, supercharger, hot cam, etc. We have no way of determining what has been to each individual engine so, if you have modified your engine, you will have to estimate how much additional CFM is needed. Remember: When it comes to electric fans "the more CFMs the better." The next step is to measure your radiator’s length and width. Use the electric fan data listed in our catalog and our website, "http://www.derale.com" to choose the electric fan with the highest cfm rating that will fit your radiator and meet the CFM requirements. You can also choose 2 (or more) smaller fans if they will give you the most CFM. Multiple fans should be mounted on the same side of the radiator. As a general rule fans that oppose each other on the radiator will impede the flow of air instead of helping it. Remember: "the more surface area you cover with electric fans the better." Q: What is the difference between a "pusher" and a "puller" fan? A: A puller fan mounts on the engine side of the radiator and pulls the air through the radiator core. A puller fan mounts on the front bumper side of the engine, pushing the air through the radiator core. A puller fan is 20% more efficient than a pusher fan. All Derale electric fans are fully reversible and can be used for pushing or pulling. All fans are set up in the factory as pullers. Q: How do I change the fan from a puller to a pusher? A: The blade assembly must be removed from the motor shaft, flipped over and re-installed. Then switch the two wires coming out of the electric motor. Q: How do I mount the electric fan? A: All Derale electric fans may be installed directly on the radiator core with the rods, clips and and pads included. |
