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mcp1810
06-23-2005, 15:17
Does anyone know where I can find an alternator fan (behind the pulley) that is set up for clockwise (facing it from the front) rotation? My NAPA alternator came with a fan that would work counter clockwise as does the only one my local dealer has listed. :confused:
john8662
06-23-2005, 16:14
it's supposed to work spinning counter clockwise. In the serpentine belt setup the accessories turn counter clockwise, why? I dunno.

So the fan you're being given is the correct one. A clockwise rotation fan will be used on an engine that is equipped with V-belts.
DmaxMaverick
06-23-2005, 16:29
There is only one direction the alternator can turn on any GM V-8 (as well as 99% of the others). The only way you can get it to turn CC is to either run the motor backwards, or get the belt to contact the pulley with its backside (belt routing problem, but you'd have other problems as well). Any accessory that uses the ribbed side of the belt will turn the same direction as the crank. This is why the serpentine belt engines have a water pump that turns opposite the crank, it is driven by the backside of the belt.

Perhaps the fan is just tricking your perception by looking like it should be turning the other way. Post a pic of it.
mcp1810
06-23-2005, 17:44
I don't have a digital camera available, but with the fan mounted, the leading edge of the "blades" are bent ninety degrees from the plane they rotate on. The patern of the blades has the hub area as the leading edge. It appears to me that this design might be an attempt to draw air forward through the alternator body as opposed to forcing air in through the front, like my old 78 camaro.
DmaxMaverick
06-23-2005, 18:35
Your fan sounds correct. The fan is centrifical, meaning the spinning blades sling the air outward, pulling air through the alternator to the hub, and outward. Your Camero was the same way, but probably didn't seem like it. A centrifical impeller can't perform "inward".

The forces of air hitting the alternator from the radiator fan and ram air are not nearly the local force of air produced by the alternator fan. It will pull air through the alternator, and out the front. Not to worry.