Quote:
Originally Posted by jtgh
direct drive is the bench mark for 1:1 efficiency
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hmmmmmmmmmmmmm!? i have seen some very sloppy crankshaft fan designs
poorly designed shrouds, air being sucked around the shroud, no shroud at all, huge radiator to fan distances and in most applications flat blades.
drag type blades VS air foils are terribly inefficient and noisy. finally airfoils are being implemented. you can HEAR the cars and trucks that don't have efficient cooling systems.
for comparative value: my 80s diesel VWs. no cooling fans. always run @ operating temp.
while we are on that subject...
the other side of the coin of direct drive fans are low ECTs while idling, during cold weather long downhills e.t.c. now THAT wastes fuel. and not just in diesels.