Patent ID: 7063125

Claim:
A method of determining an optimal fan penetration for a fan drive system used to cool an engine of a vehicle, the fan drive system having a plurality of fan blades and a closely coupled radiator, wherein fan penetration is defined as the relative location of the plurality of fan blades between the front portion of the engine and the radiator, the method comprising: (a) uncoupling the fan drive system from the engine; (b) removing a fan clutch from the fan drive system; (c) coupling a fan penetration fixture to the fan drive system; (d) recoupling the fan drive system to the engine such that the plurality of fan blades is located in a first fan penetration; (e) measuring a desired cooling system performance characteristic of the fan drive system at said first fan penetration at a desired engine operating temperature and at a desired fan blade rotational rate; (f) repeating step (e) for at least one additional fan penetration, wherein the location of said plurality of fan blades in said at least one additional fan penetration is not equivalent to the location of said plurality of fan blades in said first fan penetration; and (h) comparing the measured cooling system performance characteristics of the fan drive system at said first fan penetration to the measured cooling system performance characteristic at said at least one additional fan penetration.