Radiator Fans

Flex-a-lite is one of the leading manufacturers of automotive coolingfans of all types. When it comes to radiator fans to assist cooling, thecompany produces electric fans, clutch fans, and fans designed to bemounted solidly to the water pump, so we asked Lisa Chissus what worksbest for racing.

The answer, as you might expect, is to go with the electric fan wheneverpossible. Electric fans are powered by their own motor so they don't robpower from the engine, and dyno testing has proven that an electric fancan save you 25 hp versus an OE clutch fan. Fan clutches should never beused in racing because they only eat horsepower. If you find that youneed the extra pulling power of a mechanical fan mounted to the waterpump, Flex-a-lite produces flexible fans that essentially "flatten" outat high rpm and pull less power. They also pull less air, but if youhave correctly built your radiator box, the incoming air should bestrong enough to provide adequate cooling by itself.

Whether you decide to use an electric or mechanical fan, Chissusstrongly recommends using a fan shroud of some type. Air always followsthe path of least resistance, she says, so if you do not use a shroud,the fan will simply pull air from inside the engine compartment andlargely bypass the radiator. A shroud seals off the area between the fanand the radiator, forcing the air pulled by the fan to come through theradiator. Shrouds should be designed to cover at least 70 percent of theradiator's surface area.

Stainless Steel = Cool?

Leonard Warren gave us a neat tip when it comes to heat control and theair/fuel charge. It doesn't have anything to do with coatings, but itwas simply too good not to pass along.

"One thing many racers don't think about is to use stainless steelfasteners and insulated washers to connect everything between thecarburetor and cylinder head," he says. "Stainless steel doesn'ttransfer heat very well, but carbon steel does. You can insulateeverything, but if you use regular carbon steel bolts, the heat willjust travel down those like a wick. I know one company that did a testwith all different types of carburetor spacers. They found that nothingprovided much insulation until they switched out the bolts holding downthe carburetor and spacer with stainless steel bolts. If you are using aphenolic spacer but not getting the improvement you expected, it'sprobably because the heat from the engine is just traveling right up thebolts, past that phenolic spacer and heating up the fuel right in thecarburetor. Switching to stainless fasteners will make your phenolicspacer a lot more effective."

Oil Coolers

Since most Saturday-night races are less than 100 laps on tracks thatare 5/8-mile or less, many racers believe they don't need transmissionand rear-end oil coolers. Granted, it is critical to run a rear-end oilcooler if you are running a Nextel Cup race at Atlanta, but your LateModel may be helped by one too.

The friction created by gears meshing in the rear end produces extremelocalized heating. This heat is right between the gear teeth, soshooting an infrared temperature gun on the housing can be misleading. Asimple, belt-driven oil pump and a small oil cooler can make a world ofdifference. Keeping the temperature under control keeps the frictioncreated between the ring and pinion gears from robbing as much power andalso improves the reliability of the locker springs. By pumping the oil,you can also direct the cooled oil directly onto the ring gear as itre-enters the rear-end housing. This provides much better cooling andlubrication than relying on the ring gear to splash into a pool of oilat the bottom of the housing.

Manufacturers such as B&M Racing Performance produce high-performanceoil coolers that not only provide good heat transfer from the oil to airwith minimum size and weight, they are also very resilient in order tostand up to the abuses of racing. B&M produces a stacked-plate cooler,which you can literally stand on without damaging, and a cooler with anintegral fan for providing extra cooling power when needed.

Cool Suits

In longer, endurance-type racing events, it becomes critically importantto keep the driver cool and comfortable. For those situations, whereinsulating the driver from engine heat and providing a continuous flowof outside air simply isn't enough, driver "cool suits" are available.

Cool suits designed for racing typically employ a shirt with severalfeet of surgical tubing sewn in place. A small electric pump continuallymoves chilled water from a cooler through the tubing to keep the drivercool. By keeping the driver's trunk cool, the blood flow cools the restof the body. Other systems provide chilled air, which is blown insidethe driver's helmet. The cool air cools the lungs and, in turn, coolsthe rest of the body. The benefit of this system is that it can keep thedriver's face shield from fogging up, but if the driver is wearingcontacts, the air can also dry out his eyes.

Cool Shirt produces both types of driver cooling systems and even sellsa combination system that provides the driver with both chilled water toa cool shirt and cooled air inside his helmet. When shopping for asystem, Tom Engebretson, Cool Shirt's general manager, recommends makingsure it has a temperature or speed regulator that the driver cancontrol. If not, the driver can become chilled, which can be just asmuch a detriment to concentration. Also, many cool air systems offeroptions to filter the air before it reaches the driver, which is anexcellent idea.

Personal Protection Equipment

Personal protection equipment is just a fancy way to say the driver'sfiresuit, gloves, shoes, helmet, and anything else on his body. Thebiggest complaint about personal protection equipment, in general, isthat in order to protect you from a fire, the stuff makes you awfullyhot and sweaty.

Fortunately, many companies are working on ways to make the stuff moreprotective with less bulk. One of the latest developments is a materialcalled CarbonX that Simpson and other manufacturers of protectiveequipment are including in their products. When used in clothing,CarbonX is capable of withstanding 2,000 degrees F without damage andwon't shrink or char when exposed to direct flame. It's alsocomfortable. CarbonX can be worn next to the skin and possesses goodwicking properties. That means it keeps you more comfortable when yousweat.

The old adage still holds true that more layers in your firesuit willmean better protection, but with the new advancements in technology, theprotection is better than ever before.

286-A Gasoline Alley
IN  46222
Cool Shirt
Royal Purple
328 FM 306
New Braunfels
TX  78130
Design Engineering
Tech Line Coatings
26844 Adams Ave., Dept EM
CA  92562
B&M Racing Performance