[TR] TR3's, electric fans and fan shrouds

[Randall]

I don't recall the size for certain, but the Hayden fan that I got at Pep
Boys many years ago matches the radiator, fits easily in front of the cross
tube, and provides more than adequate cooling for stop-n-go traffic even at
115F.

http://tinyurl.com/4vqlje5

I've never seen the need for more shroud than it came with, except of course
for the piece that covers the gap between the radiator and front apron/inner
fenders.

But FWIW, I had an Audi with an interesting arrangement for the fan.  The
back of the radiator was enclosed in a sheet metal box, with the fan mounted
in an opening that matched the fan blades.  The remainder of the back of the
box was covered with flaps that acted like check valves for air flow.  They
would close off the holes if the fan tried to suck air in through them, but
allow excess pressure to flow out (ie when the car was moving fast enough
that the incoming air was more than the fan would pass).  If you really
needed the ultimate in cooling, something like that might help.

Another mod that I think would work very well (but haven't tried yet) is a
simple deflector underneath the radiator, to block part of the air flow and
lower the pressure behind the radiator.  I believe it was Geo Hahn that said
he uses one made from thin plywood.

Also FWIW, the goal should be for the movement of the car through the air to
provide sufficient cooling at higher speeds (say above 30 mph).  No
reasonable sized fan moves enough air to cool the full 100+ bhp of a TR
motor.  So if your cooling problems are at higher speeds, then you need to
look elsewhere besides the fan (unless perhaps the fan is impeding the
airflow at higher speeds).

-- Randall