by Barry Schonberger
When building my first autocross Tiger. I took into consideration all of the current tricks to keep it running cool. I installed a 2-3/8″ Indiana core, blocked off the horn ducts. built duct work from the lower apron to the radiator, ran a gutted thermostat. installed a six blade fan, adjusted the fan to shroud clearance, installed an electric pusher fan in front of the radiator, raised the rear of the hood and drilled 1-1/2″ holes in the rear of the fender wells. Each of these modifications contributed to a Tiger that ran between 200 degrees and 210 degrees in hot conditions with a modified engine. However, at standstill idle, the car would climb into the 220 degree range. The holes in the fender wells were supposedly there to help exit the hot air from the engine compartment, but at speed the turbulence is too great in the fender for the air to exit, and at a stop there is nothing to move it. When I first built the car, I looked for a small 12 volt whisper fan like those used in electronic equipment to install behind the fender well opening. All I could find was 110 AC fans at the time.
Now that I have sold the car, what do I find at my local electronic store but 12 volt whisper fans. They come in an assortment of sizes with CFM rating from 25 to 106. Not much air movement, but maybe just enough. Wired in with the electric fan, they could be turned on in traffic to clear the engine compartment of that heat buildup. They are manufactured by ICO Rally and cost around $25.
ed note: these fans are available from several sources and are even less than $25 now!