Electric Fan Install - Cool Your Engine
Cooling Tech and Why You Need A/C (In Case You Hadn't Figured That Out)
From the February, 2009 issue of Custom Classic Trucks
By Gary Robinson
Photography by Gary Robinson
The subject for our installation...
The subject for our installation was a 37 Ford pickup truck with a small-block Chevy V-8 powerplant that lacked the space for a flex fan, but still had room for an electric puller. A call was made to Scotts Manufacturing for its Terminator Fan kit with the 16-inch-diameter blade. It comes with either a heavy-duty manual activation switch or a state-of-the-art, thermostatically controlled electronic switch (for a little bit extra) and includes a basic mounting system, which we opted not to use. Other mounting systems are available from Scotts Manufacturing, but well show you how we made our own, which worked great, looked sharp, and provided a sense of pride and accomplishment when the installation was complete (wed argue thats a big part of being a hands-on custom classic truck enthusiast).
To mount the Scotts...
To mount the Scotts Manufacturing Terminator 16-inch puller fan to our 37 Ford radiator, we made some brackets from 3/16-inch-thick sheetmetal. A pattern was made out of cardboard first, then it was taken to a local sheetmetal shop where we had replicas trimmed and bent accordingly. A 1/2-inch flange on the long side of the brackets provided the mounting surface used to attach them to the sheetmetal casing on the sides of the radiator core.
We started by putting the...
We started by putting the sheetmetal mounting brackets and the Terminator Fan (with mounting tabs installed) onto the back face of the radiator for a mock-up session. This provided a general idea of where the fan would be best suited in terms of clearance and cooling optimization. We determined the best spot to be up high on the radiator core.
After measuring and scribing...
After measuring and scribing the location of each bracket on each side of the radiator core, the marks were double-checked to ensure they were symmetrical. Once this was determined, five equidistant punch marks were made on the flanges of the sheetmetal mounting brackets for drilling the 1/8-inch Pop rivet holes that would be used to attach the brackets to the radiator (four or even three holes may be sufficient). The brackets were then held in place with the scribed hash marks so a 1/8-inch hole could be drilled through both the bracket and the sheetmetal casing around the core.
Once the first mounting hole...
Once the first mounting hole was drilled on the end of the mounting bracket, a Cleco (a temporary sheetmetal fastening tool used in the aircraft industry) was pushed through it to hold it in position while the other mounting holes were drilled. As each hole was drilled, another Cleco was installed to improve stability.
After all of the mounting...
After all of the mounting holes were drilled in the sheetmetal mounting brackets, they were left in place with the Clecos in order to set the fan in a centered position relative to the radiator and the fan mounting brackets. Lines were then scribed into the mounting-bracket surface as a guide for proper fan alignment and position then double-checked with a measuring tape.
With the fan properly centered...
With the fan properly centered using the scribed guide lines on the mounting-bracket surface, a 1/4-inch transfer punch was put through the fan mounting tabs and gently tapped with a hammer to make an impression on the mounting bracket.
Once all the fan mounting...
Once all the fan mounting tab location holes were marked with a transfer punch and hammer, a spring-loaded center punch was used to deepen the impressions made by the transfer punch. This helps to guide drill bits when drilling pilot holes into any material.
The fan bolt holes on the...
The fan bolt holes on the mounting brackets were 1/4-inch in diameter. These couldve been opened up using a 1/8-inch drill bit followed by a 1/4-inch drill bit. However, since we had a Whitney sheetmetal punch at our disposal, we opted to use it for the cleaner, burr-free hole it provided.
After the fan mounting holes...
After the fan mounting holes were punched into the mounting brackets, they were bolted to the fan mounting tabs. Then the entire assembly was remounted to the radiator with the sheetmetal Clecos holding it in place, while we double-checked that the fan assembly was correctly centered onto the core.
The whole assembly was mounted...
The whole assembly was mounted properly, and the brackets were removed from the fan. The brackets created some blockage of the radiator cores surface, so they needed to be opened with holes. This looked cool and was functional. We sprayed outline dye on the brackets, then used a circle template to lay out a pattern that would make the holes as big as possible for maximum airflow without sacrificing structural integrity.
Once an acceptable layout...
Once an acceptable layout was created, each hole was center-punched and bored out using a hole saw equal to the outer diameter of each scribed circle on the bracket.
Upon completion of the hole-boring...
Upon completion of the hole-boring process, the fan mounting brackets were carefully deburred with a file, hand-dressed, and sanded smooth for improved outward appearances.
With the fan mounting brackets...
With the fan mounting brackets completed, they were bolted to the fan mounting tabs using 1/4-inch coarse thread nuts, Nylock locking nuts, and AN washers. The assembly was then mounted to the radiator core, and the mounting brackets were affixed to the sheetmetal core casing using 1/8-inch aluminum Pop rivets. Sheetmetal screws couldve been used here, but we felt they may loosen due to vibration. The Pop rivets provided a more stable mounting system for the brackets.
The next step in making the...
The next step in making the 16-inch Scotts Manufacturing Terminator Fan operational is to mount the radiator back into position in the framerails in front of the engine. Then the wiring process can start.
Hooking up the Terminator...
Hooking up the Terminator Fan is a simple process, whether you use a manual or thermostatically controlled switch. The lead wires from the electric fan motor already have a dual-prong male plug connected to them. These need to be connected to a ground and activation source (the switch), which is accomplished by crimping the female wire ends to the switch wires from the kit.
After installing the female...
After installing the female connectors, we plugged them into the dual-prong male plug from the electric fan motor. Tie-wraps were used to keep the wires together for a clean-looking installation.
Once the wires were connected...
Once the wires were connected to the fan, they were run to a fuse link. We could have used the fuse link in the kit, but most presently available aftermarket wiring kits have a fan power-terminal fuse in their circuit panels.
After making the proper ...
After making the proper connections to energize the system, all that is left is to mount the manual fan-activation switch (unless the state-of-the-art electronic thermostat switch is used). As you can see, ours found a convenient and inconspicuous home beneath the dash to the immediate right of the steering column.
As this photo shows, the Scotts...
As this photo shows, the Scotts Manufacturing Terminator Fan develops an impressive amount of airflow even through this thick stock-style radiator core. Since many early style trucks have limited or no ventilation, adequate airflow is key in keeping contemporary powerplants from blowing their tops. And remember, if you run into trouble keeping vital fluids cool, give Scotts Manufacturing a ring. Someone there will probably have an answer for your temperature troubles.
In the construction process of a custom or classic truck (or any other type of vehicle, for that matter), certain necessities must be included to complete the vehicle and drive it on the road. These dont include things such as air conditioning, a stereo system, and power brakes (though some may argue against this). They do include things such as a fuel system, hydraulic brakes, steering, wheels and tires, an engine, and other similar necessities if you expect to actually drive your pickup.
This brings us to the cooling system. Nearly every hydrocarbon-burning internal combustion motor needs one to maintain normal operating temperatures. Yet even though a radiator does a great job of dissipating heat from hot, pressurized engine coolant, its not enough. There must be sufficient airflow through the cooling fins of the radiator to help it remove engine-heat energy from the coolant flowing through its core. The simple solution is a fan mounted to the water-pump pulley, of course. However, as many who have ventured down this path will tell you, this isnt always the easiest solution. Clearance problems, excessive noise, and horsepower draw from the motor are some of the downsides to a basic flex fan. Even a clutch fan doesnt always provide the solution to the problem, since clearance and the need for a fan shroud remain obstacles to an efficient engine-cooling system.
Yet, as difficult as the problem may seem, there is a simple solution: Use an electric fan. The advantages fans provide are that they work well in tight clearance situations, most have their own shrouds, they are available in various sizes, and they are very versatile in regard to mounting locations. In addition, they can be either manually or thermostatically controlled. Come to think of it, weve just described some of the traits associated with the Terminator Fan kits from Scotts Manufacturing. These kits are available in diameters ranging from 13 to 16 inches, and they use a slim and powerful 3 ¾-inch electric motor with a low 12-amp draw. When attached to the efficiently designed blade of the shrouded Terminator Fan, they move a high rate of air through the radiator, whether mounted in front of the core to push the air or behind the core to pull the air through. Best of all, they are versatile, can be ordered in many configurations, and are only some of the cooling products Scotts Manufacturing offersother products include oil coolers, tranny coolers, mini-fans, Flow-Cooler water pumps, and mounting hardware. No matter what the application, Scotts Manufacturing can probably put together a cooling equation thatll work for you.
Johnny Rottens Garage
Scotts Manufacturing Company
25520 Avenue Stanford