Mark Houlahan
Brand Manager, Mustang Monthly
October 1, 2003

Horse Sense:
When adapting from a clutch-driven fan to an electric fan, it's wise to think about the horsepower level you are dealing with and the expected horsepower capability of the fan(s) you choose. Remember, you can never have too much cooling, so if you're borderline on the horsepower requirements of the fan you are looking at, it makes sense to move up to the next biggest fan or a dual-fan system.

When it comes to performance engines, higher compression, higher operating rpm, and tighter engine compartments (blowers, intercoolers, and so on) result in higher operating temperatures. To tackle this situation, you'll need something more than the clutch fan and copper/brass radiator that came in your Mustang. For many, the problem of keeping their "hot" 5.0 cool is due to the fact that many cooling systems-from four-cylinder to V-8 swaps-were kept in place to save a few bucks. Now, realistically, how is a stock four-cylinder radiator and a parts-store flex fan going to cool that stout 5.0 you built? It's not. So it's time to buck up and realize you need a real cooling system for your Mustang.

For the typical bolt-on 5.0 engine, a nice, fat, single-row or medium two-row aluminum radiator will do the trick. You could throw in a performance fan clutch and new fan. Better yet, drop the mechanical fan altogether and go with an electric fan for more cooling-system control and to free up some horses.

Finally, don't forget the cooling medium and accessories. Unless yours is a dragstrip-only Mustang, in which you should run straight water, you'll want a fresh mix of coolant and water (preferably distilled water), some form of cooling system enhancer (we're using Redline Water Wetter in this instance), fresh hoses, a quality thermostat, and a proper gauge to see what's going on.

This recently acquired '85 GT hatch was constantly running hot at highway speeds, and the radiator had several pinhole leaks that had been pinched off, reducing the radiator's marginal effectiveness. Basically, the cooling system was a mess. We contacted Griffin Radiator for one of its aluminum street radiators. Knowing this tired 5.0 would be gone in less than a year to be replaced by a built 351W, we opted for Griffin's upgraded two-row unit that incorporates 1 1/4-inch tubes. It's overkill for now, but it will be just right for the built-up Windsor.

As we've done before with many of our project vehicles, we decided to ditch the stock fan and go electric. This time we chose a Flex-a-lite Black Magic M150. Flex-a-Lite fans are now avail-able with color-impregnated shells. So, if you want a red, blue, or yellow fan to complement your ride, Flex-a-lite has you covered.

Because this GT is an automatic, we'll need a special tool to disconnect the cooler line fittings, but other than this one item, the installation of the radiator, the fan, and the fan's wiring is straightforward and requires just a few simple hand tools.

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