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Article Overview:

The first in a series of articles detailing what I consider to be things that I have wanted to get done on my 1966 Malibu for a long time, but have so far been too busy to get around to. This article will show the process of switching from a belt driven 5-blade clutch fan to a dual 12″ electric setup. I also intend to do some before and after drag-strip tests at LACR to determine if there are any performance benefits to the conversion.

Parts that I used in this conversion:

• Derale Dual Cooling fan (DER-1928)
• Delta Control Control Controller (VC-1260)
• Delta Current Control Thermal Probe ( TS-104)
• 1/2″ steel tube and 2″ steel strap
• Various wire and terminals from around in the garage

The bottom line is that this conversion is not cheap and will run you around $400 when all is said and done. At least you will have me as a guinea pig to determine if the conversion is worth the time and money.

Building a Mounting Bracket:

The new dual electric fan from Derale (DER-16928) as it looks fresh out of the package.



Taking measurements of the fans mounting tabs. I will not be using the nylon zip ties that came with the fan for installation. This car sees quite a bit of road use, some of it far from home and I would prefer a more positive method for retaining the fan.

A basic drawing of the mounting hole configuration of the fan assembly.



Here is have come up with the basic design for my fan mount. The is about 1/2″ of space between the radiator and the inside of the fan shroud that will allow me to hide my mounting bracket between the fan and the radiator for a very clean looking install.



I have drilled the holes to mount the two sticks of 1/2″ steel to the fan shroud based on the measurements that I took of the fan shroud assembly.



Next I used two pieces of 2″ steel strap to for the base mounts for my bracket. At first I attempted to use 22 gauge sheet metal, but found it to be too flimsy and went with something a bit thicker. Make sure to carefully mark you holes and use a center punch before drilling to get the best results. Also I found it very useful to have the actual radiator on hand for this part of the project as these old Chevy radiators are far from straight. I made up for this by making my mounting brackets parallel to each other, but not to the radiation. The fan shroud itself is pretty straight so I did not have to do much in that area.



Clamp everything down good and weld it up. Thanks to Steve at Hotrods to Hell for the help with the welds.



Here is a look at the final welded bracket. All looks good so far.



I removed the fans from the shroud and bolted it up to my bracket to see how everything fits together. It all looks good. A benefit of Derale’s design is that the fans can be removed individually from the fan shroud in the event that they require service down the road.



Here is a second view of the bracket that gives you an idea of how everything went together.



Here is the whole radiator and fan assembly with the fans reinstalled. Looks nice and clean and it is strong enough that I can pick up the whole radiator using the fan shroud. I also like the fact that the bracket is nice and hidden behind the fan shroud.



Here is the fan assembly mounted in the car.



Another view of the complete assembly mounted in the car.

Wiring:

The installation of an electric fan requires a simple, but important bit of wiring and electrical work. Here is a picture of the Ford starter solenoid that I will be using to route power to my fans. I picked up this $5 starter solenoid out of a late 80′s Ford Taurus of which there are plenty in most local pic-ur-part style junkyards. On the Taurus that I got this from it was mounted on the driver side inner fender.

After doing more reasearch I discoved that the Ford solenoid is not rated for a constant duty cycle and will not work, fortunatly I have discovered an elegant solution that I figured couldn’t hurt to try. Delta Current Control offers an electric fan controller the adjusts fan speed to keep your coolant temperature in a close range as opposed to a relay and temp switch that will allow your temperature to fluctuate quite a bit. I ordered the #VC-1260 (60 Ampere Controller) and #TS-104 (Radiator Temp Sensor) from the DCC paypal store.

My part arrived from DCC within about a week, and I quickly installed it. Since I had already run most of the wires needed, installation took me only about 15 minutes.



Mount the controller on the radiator core support.



Hook the controller up to power with the supplier fusable link.



Connect the fan and thermal probe to the DCC unit.



Close up view of the thermal probe.

Let me just say, this product has been working wonderfully. So far I have given it the Taco Bell drive through test, a 100 mile freeway drive, stop and go traffic, and a trip to LACR and I could almost swear my gauge is stuck at just over 195 degrees. I run a 195 thermostat so this is correct for my situation. Read a more detailed description of this product here in the DCC Product Spotlight.

Performance Testing and Final Thoughts:

I ran the car at LACR before the installation of the electric fans to establish a baseline for performance. The switch pitch stall converter on my TH-400 allows many options so I ran once with it in high stall and one in low stall.
Baseline Performance:

• 14.296@94.065MPH – High Stall
• 14.863@99.200MPH – Low Stall
• Best trap speed – 101.82
• Best ET – 14.296

Sources:
If you use any of the vendors listed, let ‘em know you saw them here.

Hotrods to Hell, Inc
100 East Prospect Ave
Burbank, Ca 91012
818.842.4360
www.hotrodstohell.net

Derale
3901 Medford Street
Los Angeles, CA 90063
800.421.6288
www.derale.com

Delta Current Control
www.dccontrol.com

Industrial Metal Supply
8300 San Fernando Rd.
Sun Valley, CA 91352
800.371.4404
www.industrialmetalsupply.com

Additional Reading:
Dyno testing on fans, alternators and oil…..all here!