Radiator Tech Talk

Unfortunately, much of the learning I do is by trial and error.  Such is the case when it came to the decision regarding which radiator to purchase for my first mini-sprint.  While I am sure that much of the decision came down to cost, (as my wife often reminds me, I am the biggest cheapskate around) I also received some bad advice.  I was told that a good copper or bronze radiator would do the job just as well an aluminum racing radiator.  After overheating several times and endless attempts to increase the air flow to the radiator, I threw in the towel and purchased an aluminum racing radiator.  It was like black magic—my overheating problems went away instantly.  After several years in the sport now, I have seen numerous racers go down the same path.  Most often I hear racers say, “I’ll just use the radiator off of the bike”, or “I’ll buy a radiator off of a compact car and use that”.  The reasons why aluminum racing radiators perform so well are not really black magic.  In this article we’ll take a look at the benefits of an aluminum racing radiator.

 
The Hard Facts
The more horsepower an engine creates the more heat it creates.  Once an engine reaches a high enough temperature, it begins to loose power and ultimately risks the threat of serious damage.  Cooling problems are a major cause of DNFs in all types of racing.  Okay, maybe this is an oversimplified view, but you probably get the point, the radiator is important to the performance and longevity of your racing engine.
 

How Does it Work
The job of the radiator is to remove an engines unused heat.  This is accomplished by the coolant which carries the heat out of the engine into the radiator.  Once in the radiator the coolant moves through the tube/fin area where the engine's heat is dissapated.

Why an Aluminum Racing Radiator
Although the concept of a radiator is quite simple, getting a radiator to work properly under the extreme conditions of auto racing is not as simple.  Most stock motorcycle and automotive radiators are not designed to stand up to the rigors of auto racing—this includes both their strength and performance. 

Most radiators for street applications are designed around the principle of getting the job done for the lowest possible cost.  As a result most stock/OEM radiators are merely adequate for the task of cooling a car or motorcycle engine during normal usage—forget about under the stresses of racing.  The tubes in a radiator are the primary source of cooling and the fins are secondary.  Since tubing is much more expensive than fins, most stock/OEM radiators increase the amount of fins to reduce the amount of costly tubing required.  A good aluminum


 

Experience has taught me that there is no replacement for a quality  aluminum racing radiator when it comes to cooling your racing car.
racing radiator does just the opposite—more tube surface for primary cooling and fewer fins allowing it to cool much more effectively.  The increased number of fins on a stock/OEM radiator can also adversely affect the performance of the radiator.  Since additional fins allow less space for dirt and debris to pass through, it becomes harder for the air required to dissipate heat to pass through the radiator.  This is very important in auto racing where more dirt, rubber and other debris is present.  Additionally, the higher fin count can represent a small air restriction which causes air to flow around the sides of the radiator rather than through it.  One additional thing to keep in mind is that most stock motorcycle radiators are designed to work with unrestricted airflow.  When placed in a racing car behind or under bodywork it becomes much harder for them to work efficiently. 
 

Note the difference between the width of the tubes used in an aluminum radiator (right) compared to the width of the tubes used in a copper radiator.  The Aluminum radiator's tubes are much wider providing much more of a cooling surface.

Two additional benefits of aluminum racing radiators are strength and weight.  Most aluminum racing radiators have the tanks welded to the tubes rather than brazed or sealed with epoxy.  This makes the radiator much stronger and more capable of standing up to the rigors of racing.  Aluminum racing radiators are also much lighter than stock/OEM radiators because of the lighter materials and lower fin counts.

Taking It a Step Further
Late in 2003 FOZ Racing Products introduced a line of aluminum racing radiators designed and manufactured specifically for use in motorcycle-powered racing cars like mini-sprints, dwarf cars and modified midgets.  The FOZ Aluminum Racing radiators feature the highest quality Delphi cores and have been designed for the unique performance and mounting requirements of this class of racing.  FOZ Racing Products’ Larry Fasse explained, “We’ve tried to make it as easy as possible to mount our

radiators.  For instance, we offer a radiator just for the R6 where the location of the inlet and outlet have been re-positioned so that you don’t have to criss-cross hoses to hook it up.  We also offer radiators that are configured for use with fuel injected engines that require additional ports.  Since so many of our customers are running cars that are one off or limited production creations, we also make it easy and economical to order a radiator that is built to a customer’s individual requirements.”  For more information on FOZ Aluminum Racing Radiators visit www.speedpartz.com or call 513.755.7205.
 

FOZ Aluminu Racing Radiators are manufactured for all forms of motorsports including mini sprints, modified midgets, micro sprints, dwarf cars, modified lites, tq midgets, sprint cars, midgets, shifter karts Formula Ford, Formula 2000, SCCA Road Racing, ATVs, Formula SAE, SAE Mini Baja and many more.  Additionally, we've custom manufactured aluminum radiators for performance street cars including Honda, Ferraris and Porsches.  Call us with your specific requirements, we're ready to help.

The fins on an aluminum racing radiator (see bottom picture) are also typically further apart which allows the increased dirt and debris inherent to racing to pass through more easily, instead of clogging the fins and restricting air flow.  (Top picture is a production motorcycle radiator)
 
 
 
 

Remember all of the great products from Speed Partz for Christmas and your winter rebuild