[TR] Push or pull

[fishplate at charter.net]

---- Brian.L.Jones at gsk.com wrote: 
> My instinct leads me to believe a puller will move more air through a 
> radiator than a pusher.

I'm not sure of the test parameters, but a properly installed puller will flow better than a properly installed pusher.

As I see it, a proper installation of a fan includes a shroud.  If you shroud a pusher, then when the vehicle is in motion and the fan is ~not~ energized, air is blocked from normal laminar flow through the radiator by the shroud.  With a puller in the same configuration, air hits all points of the radiator face more or less equally (small mouth notwithstanding), so that more flow is experienced.  The rear shroud may limit total flow somewhat, though, maybe.

When the fan is energized, then there may not be as much difference between pusher and puller - probably both are more effective at moving air through the exchanger than the stock (unshrouded) fan.

Jeff Scarbrough
Spitfires and a TR6