Whenever a Mustang's engine is modified to make more power, the demand on the cooling system increases. More power means more heat, and the limitations of the stock Mustang cooling system can soon become apparent. Marlon Mitchell from Marlo's Frame and Alignment has a '66 Mustang coupe with a built 308-inch small-block. During the summer he runs into some serious heat in So-Cal's San Fernando Valley. Problems can arise with the limitation of the stock radiator capacity and the limited ability of the original cooling fan to move enough air.
The SPAL kit includes steel...
The SPAL kit includes steel mounting straps, a big improvement over plastic ties that must travel through the radiator core to attach the fan. The relay, wiring, and temperature sending unit are also shown. The 14-inch-diameter fan (PN 30102041) moves 1,623 cfm of air, and the motor has a 10,000-hour life span.
The OE radiator has been replaced in Marlon's '66 with a high-performance aluminum unit, so that aspect of the cooling quandary has been addressed. It's 4 inches thick, so it has pretty much reached the limit for core thickness before air travel is impeded. At idle, a mechanically driven cooling fan only turns as fast as the engine, so when heat circumstances conspire against the car, there's no reserve air movement to fall back on. Revving the engine to increase fan speed in an attempt to cool the engine just makes more heat. What's needed to complement the radiator is a powerful electric fan that works at full speed, regardless of engine speed.
The SPAL electric fan we installed on Marlon's car fits this description perfectly. It's a low-profile unit, so interference with pulleys isn't a problem. The SPAL unit includes a complete electrical harness with a relay and detailed instructions. While the fan is thermostatically controlled, it can also be equipped with a manual override. For air-conditioned cars, the fan turns on anytime the A/C is activated.
The SPAL fan also has a closely fitted built-in shroud to channel airflow. This will be a considerable improvement for those with an open radiator on all sides. Furthermore, an electric fan frees up the power used to drive the mechanical fan. Make sure your battery and alternator is up to the task and you'll enjoy the peace of mind that comes with the extra cooling protection of SPAL's electric fan.
 Here, the mechanical fan has...  Here, the mechanical fan has already been removed and the electric fan is being test-fitted for the first time. The fan attachment bolts are then reinstalled to retain the water pump pulley. Rotate the water pump pulley once the fasteners are seated. If there's interference, then shorter bolts must be installed. Shorter fasteners are usually needed, so you might as well pick them up prior to the installation. |  With the SPAL fan in position,...  With the SPAL fan in position, clearance at the fan motor and water pump pulley is close but adequate. In instances where interference is a problem, the fan can be located a little off-center on the radiator to create the required clearance. Variables include radiator thickness, radiator mounting method, and water-pump type and snout length. Adjustable motor mounts can also be used to alleviate a tight-fit situation. |  Here is one of the four steel...  Here is one of the four steel mounting straps included with the kit. The plastic end fits into the fan shroud for a secure fit. A bench vise will be handy when it's time to shape the mounting straps. This one has already been measured and marked to indicate where the bend needs to be. |
 After careful comparison to...  After careful comparison to the application, the strap is clamped into the bench vise and the first right-angle bend is accomplished. The distance between the plastic bracket and the angle bend is equal to the distance from the outer rim of the fan shroud to the edge of the radiator core. |  Next, the steel strap is repositioned...  Next, the steel strap is repositioned in the vise so this final right-angle bend can be made. This bend will make the strap rest flat against the radiator core support once installed. |  Once the steel mounting straps...  Once the steel mounting straps are formed, the fan is simply attached using the stock radiator mounting holes. |
 With the fan in place, it's...  With the fan in place, it's relatively straightforward to hook up the electrical connections. Connect the harness plug as shown here and route the wires to the inner fenderwell, where the relay will be installed beneath the starter solenoid. When routing the wires, be sure to keep them away from heat and moving parts. |  Shown here is the wiring harness...  Shown here is the wiring harness for the SPAL fan. The bottom of the relay is at the upper right, while the top has already been installed on the car beneath the starter solenoid. |  Before completing the job,...  Before completing the job, everything is test-fitted. Here, all of the wires are trimmed to the desired length for a clean installation. |
 The relay snaps into position...  The relay snaps into position on its housing, which has already been attached to the inner fender. Use zip ties to keep wiring in place. |  Completing the wiring is a...  Completing the wiring is a simple matter. Here, the final ground connection is accomplished. The hot lead for the fan also is visible as it attaches to the solenoid. |  If thermostatic control is...  If thermostatic control is not utilized, you can install a switch, purchased separately, for manual control. If a thermostatically controlled fan is desired, then the switch can still be used to override control of the fan. |