not quite so panic, for our purposes [we're not building turbines] the reason all fans are close [or have shrouds] is so they draw air through the rad rather than from the area behind the rad - GM engineers weren't just randomly positioning things in there without good reason, you'll find every old GM vehicle has the fan spec'd within 1/2-3/4" of the rad, or they have a shroud [a
fan shroud, not a
rad shroud]
as I pointed out above, a shroud serves to force the fan to draw air from straight ahead, through the rad, otherwide it'll draw air from the sides, which is why the critical point is that the blades be pretty well centered in the shroud hole, not in front or behind it
a shroud need only enclose the fan blades, not the entire rad surface, and GM in fact
made all shrouds that way early on when the layout resulted in the fan being further away than "dangerously close" - my 58 would have had a shroud similar to the one I scrounged from a wrecker to cure it's heating up at idle, even in cool weather it didn't do well without it, with it even the hottest summer days are not a problem
when the vehicle is at speed, air flow thru the rad happens regardless of the fan [at high speeds, in spite of it], when the fan functions is with the vehicle at rest, and under no load, it doesn't require every square inch of the rad to have air moving thru it to maintain the correct temp
Bill
