Originally Posted by 454 Rattler
How close to the radiator fins should the blades or shourd be mounted ? It's a pusher fan going into a 36 Ford with a small block. Theres a very small shroud around the blades.
Thanks, guys !
My Spell Check didn't catch the misspelling of the word Clearance in the title !! Sorry about that !
Pusher fans lack effectiveness, the area they cover against the total radiator core area is pretty small. The idea with the shroud is to promote some siphon flow around the outside of the shroud by the pressure reduction of the air exiting the fan. This isn't as effective as it needs to be. The most effective set up is a puller fan on the engine side sitting at the exit of a shroud that seals the perimeter of the radiator. This develops a low pressure area behind the core so air flow will occur across the entire surface area. This level of efficiency is not considered visually attractive so is seldom seen on street rods. Cooling of these machines just continues to be a problem.