Volume III, Issue 3, Page 38

In the last issue we took a detailed look at aluminum radiators, examined how a high-quality core is built, and determined how a well-engineered piece can really help cool a hot-headed motor. Aluminum works as a drag racing radiator material, that’s a given. But another big key to cooling is the fan(s) and shroud.

Fan Dangled…

Here’s an example of a cooling fan arrangement Ron Davis uses and recommends. Take a very close look at the shroud. It completely seals the back of the radiator.  The concept here is to literally force all of the available air to flow through the radiator. (Ron Davis Photo)

Electric fans are pretty much the norm now, but there’s a catch: You need something with sufficient power to cool the engine, but at the same time something that doesn’t have a ridiculously high amperage draw. This is critical for most bracket cars, because there is likely no charging system, so the performance of the fan diminishes as it trips the quarter-mile.  And if you don’t have a tow vehicle at the end of the track, the situation is compounded as you drive back to the pits.  Remember that vehicle speed is slow on the return road.  Slow speed equals low airflow through the radiator and that can result in overheating.  Remember too, if the fans consume too much amperage, then something else might suffer (for example, your electric water pump, your electric fuel pump, your ignition system or even bracket racing electronics).

Given this situation, Ron Davis Racing Radiators spent considerable time researching cooling fans that fit the needs of bracket racers (big volume, low amperage draw).  Davis offers 12-, 14-, and 16-inch diameters.  The (very) basic specs are as follows:

Part Number                          Diameter                    RPM                           CFM  
EF 120                                   12-inch                       2300                           1576
EF 140                                   14-inch                       2400                           1828
EF 160                                   16-inch                       2400                           2197

Leading A Horse To Water…

All of these fans have a low amp draw, but Ron points out that one of the other secrets to proper cooling is to seal the radiator to the fan.  Typically, an integral shroud surrounding the fan(s) allows the largest volume of air through the core in a pull-through application. 
You absolutely must figure out a way to bring the air to the radiator core. The idea is to provide a constant supply of it through the radiator so that the coolant is reduced in temperature.  Increasing the airflow through the radiator improves the cooling and as a result, a shroud is almost mandatory in high-performance applications. Unfortunately, the shroud is often missing on many older cars or because it was never installed on a freshly-built car. OEM shrouds were often manufactured from plastic and as result the condition typically degrades dramatically over the years.

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