Quote:
Originally Posted by ZeGermanHam
Without the shroud, the fan has no ability to pull air through the radiator, so you're basically rendering the fan useless by doing that. Not necessarily an issue if you spend very little time in traffic, but if you do, it's going to overheat.
|
The air has to come from someplace. While some may be pulled from behind the radiator and pushed back over the engine, it would never be as much volume as even a normal 4-blade fan would pull. The fan creates a low-pressure spot between it and the radiator and the air is pulled thru the radiator to that lower pressure and then thru the fan and over the engine.
At cruising speed or above, the air flow is much higher due to the forward movement of the radiator, but the fan still creates that low-pressure area, which assists the air flow thru the radiator.
That's why the older (pre-1970) pickup trucks usually only had a heavy duty fan and no shroud. It was all you needed.