Walk up to the plate already three strikes in the hole, and you might as well not even show up. You've struck out before your at bat even begins. That's the predicament we faced with our '93 Mustang project car. It boasts a big 532ci motor, a heady 775 hp, and lives in a brutal Texas climate that rarely drops down below triple digits in the summer. With the unrelenting heat just around the corner, and race season quickly approaching, we had to come up with an effective and cost-efficient solution for our formidable cooling system demands. While we were expecting to shell out close to $1,000, after doing some research and scouring eBay, we got the job done for just $305.
The rock of Project Fox's new cooling system is a Summit universal aluminum radiator that lists for $160. It was matched up with an electric cooling fan pulled out of a late-model Lincoln Mark VIII, and a Summit 160-degree thermostat. Controlling the fan is a Derale thermostat switch, which automatically turns the fan on at 180 degrees, and shuts it off at 165 degrees. This simple arrangement eliminates the need to manually activate the fan with a toggle switch, and is far less expensive than a programmable aftermarket fan controller. If necessary, there's always the option of wiring in a manual override switch in concert with the automatic on/off setup. Finally, since the Mark VIII fan has a healthy appetite for juice, we hooked it up to a Dakota Digital 70-amp relay.
Although it will be spring by the time this story hits the newsstands, we're putting it together in the middle of January. Consequently, the cobbled-together cooling system we're touting has yet to be tested, but we're quite confident that it will hold up just fine in the unrelenting heat. That's because Summit's budget-priced radiators are proven performers, and the ace in the hole known as the Mark VIII fan. This little beast flows in the neighborhood of 5,000 cfm of air-which is a solid 1,000-2,000 cfm more than the best aftermarket fans around-and can be scored online or out of a salvage yard for $50.
In a hobby whose participants are predisposed to chuck anything that's stock in the dumpster, those figures may seem alarming. Think about it for a few seconds, however, and it all makes perfect sense. Compared to the typical musclecar, late-models feature very small radiator cores due to cramped engine bays, and the need to reduce weight. In fact, traditionalists would be shocked at the diminutive size of modern radiators, many of them supporting in excess of 700 hp in hopped-up GM LS- and Ford mod-motor applications. Throw in the fact that most late models have small grilles, non-functioning grilles, or no grilles at all, and it's obvious why their cooling fans have to pull so much air. Another huge bonus is that the OE's have to design their products to last for hundreds of thousands of miles. While you'll have to wait a few more months for a progress report on how well Project Fox's cooling system performs in stop-and-go traffic, in the meantime, here's how to assemble a budget cooling system à la carte. Thanks again to Bill Buck Race Cars in Austin, Texas for letting us take over their shop for the day to get Project Fox one step closer to completion.
After taking the appropriate measurements in Project Fox's engine bay, we ordered a 27.5x1
Mark VIII Fan
Universal consensus is a rarity in a scene as opinionated as hot rodding, but not when it comes to budget cooling fans. Whether the online message boards you frequent cater to the Chevy, Ford, Mopar, Pro Touring, Pro Street, or drag racing creed, typing "Mark VIII fan" into the search box will yield similar results. Just about everyone agrees that, dollar for dollar, it can't be beat in terms or airflow, and will cool just about anything you throw at it. That said, "Mark VIII" fan is a somewhat ambiguous term used to describe a variety of fans Ford installed in many of its cars in the '90s. These fans come in both single- and dual-speed designs, and with different combinations of fan motor and fan blade arrangements. Nonetheless, whichever one you get, they all move serious air. In independent testing, the different variants of the Mark VIII can move anywhere from 4,000 to 5,000 cfm of air.
As the name implies, the true Mark VIII fan is an 18-inch unit that equipped '93-98 Lincoln Mark VIII coupes. The '93-96 models are two-speed units, while the '97-98 models are single-speed fans that relied on a factory variable-speed controller. The later fans are rumored to flow about 500 cfm more air, and are easily identified by their white pigtail plugs, however, insisting on a single-speed fan isn't necessary. The dual-speed fans move so much air in low-speed mode that many users report that their fans never even switch into the high-speed circuit. Ford installed similar 18-inch fans with equally astounding airflow into mid-'90s Thunderbirds and Mercury Cougars. Ford also installed 17-inch fans in Tauruses equipped with 3.8L V-6 engines that move some serious air as well. Another benefit of transplanting a factory fan into a hot rod application is that they include an integrated shroud. So if you need an affordable high-performance fan, you now know where to look. -Stephen Kim