I know the oil cooler isn't ment to cool the air cooled engine, its ment to keep the oil temperature below the temperature level at which brekdown occurs. I learned from putting the electric fan on my van that the good air flow across my transmission oil cooler at lower speeds made a dramatic difference in the transmission oil temperature and I have to believe there would be a noticable difference in the oil temperature of an air cooled V-twin engine that had a fan forced oil cooler. Its a matter physics. The greater the air flow across the fins of the cooler, the more heat that is dissipated into the air.