Pushing air through the radiator of an off-road vehicle like a tractor or a bulldozer has a very practical application that has nothing to do with thermal efficiency. It helps prevent the radiator fins from getting clogged by dirt, dust, or vegetable debris. When I'm bush hogging head-high vegetation in my pastures, the cloud of weed seeds and leaves getting blown out of the grill is a sight to behold. If you get your D-9 Cat going 50 MPH down the road and the airflow from the fan is opposing the ram air direction, all bets are off. Please mount a Go Pro camera so the rest of the world gets to watch your self-destruction, though!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!