I Agree. I built a fan shroud that covered the whole blade and the car
cooked. Same shroud trimmed so that 1/3rd of the blade is exposed and I
can tow a tent trailer at 115F in heavy trafic and not get hot.
P.S. I use the Volvo 5-blade metal fan - no trimming required.
Jc
>>> <Carmods@aol.com> 11/27/97 09:18am >>>
In a message dated 97-11-27 06:29:49 EST,
STUART_BRENNAN@HP-Andover-om3.om.hp.com writes:
<< A while back somebody said that our stock fans were located too far
into the shrouds, and that a lot of air was getting flung off the
blade tips inside and recirculating. >>
Fan Design
Rear wheel drive automotive fans act as combined axial and centrifugal
fans because the air coming into the front of the fan from the radiator
must immediately turn 90 degrees to get around the engine. In an Ideal
design, the air travels axially, with the guidance of the shroud, through
the front two thirds of the fan and then turns 90 degrees radially. To do
this, the shroud should end so that the rear third of the fan blades are
exposed behind the shroud. If the shroud covers more than two thirds of
the fan, the distance for the air to turn is shortened and the efficiency of
the fan is reduced.
Relocating The Fan
Fan mounting hubs on Ford fans have a press fit on the pump shaft. The
fan can be moved rearward by removing the pump and pressing the
mounting hub further rearward on the shaft. There should be enough
room to get the ideal one third fan blade dimension in a stock Tiger. if
there isn't then the shroud must be located too far rearward.
John
Logan
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