<VV> Electric cooling fan results

[Tony Underwood]

At 06:03 PM 8/1/2007, you wrote:

>  To absorb more heat, there's only one option left, MORE AIR FLOW!!

This is obvious.   A better fan that's more efficient is 
needed.  Something which wouldn't require as much power to spin.

>The FIAT was also cooling an engine with well less than half the HP, 
>so, its cooling demand isn't even as high as a Corvair!

Still, the Fiat's fan design looks much more efficient, makes me 
wonder whether a similar design would do on a 'Vair engine with the 
proper shroud around it.   Hey, there aren't that many fans out there 
that come even close to what's needed.

>The scoops in the rear fenders of modern Porsches are for radiators 
>(meaning water cooled cars) and/or intercoolers.

This is also obvious... no air cooled Porsches for years.

>Again, looking at the shroud pressure of an air cooled engine (which 
>is WAY higher than the air pressure through a radiator, by something 
>like a factor of 10!

The designs are nowhere similar.   Radiators in cars are intended to 
hang in the breeze, with a fan in place to suck or blow air through 
them only when there's not enough forward motion for the breeze to do 
it.   Serious pressurization (or suction) of the area between an 
electric fan and the radiator is unnecessary because the air flow 
requirements at idle or low speeds are low.  This is middle school science.

However... if the car is running at high speed on the Interstate or 
the straight stretch at VIR and working the engine hard, and if you 
were to measure the mean pressure in front of that same radiator I'd 
wager it wouldn't differ from the shroud pressure of an air cooled 
engine by anything *near* a factor of 10.    In fact, I bet it would 
be pretty close, if not just as much or maybe even more.

Get that calculator out and see what sort of pressure would be in 
front of the radiator of my '66 Plymouth at 70 mph... with the front 
grill opening at around 11" x 50" feeding a "box" funnelling that 
pressurized air against a radiator 30" wide and 22" tall.


Back to Corvairs:   We need to get more flow through the 
engine.   And, we need to figure a way to do it without costing hp.

Isn't this the whole point behind this thread to begin with?

A stock late model 'Vair engine has a lot of restrictions to air 
flow... including the lower shrouds and their additional hardware 
that does nothing to improve cooling at all, which is why the engine 
cools better without them.   But then there's no engine heat control 
and no heater in winter...  no big deal for a race car, or me and the 
'60 though.  ;)   Anyway, it's wearing a mag fan now which, sorry as 
it is, still cools better than that '60 fan did.   But the mag fan 
ain't enough if the engine in question is turbocharged and tweaked 
and/or run hard.   Things get hot fast, been there done that bought 
the rebuild kit.


So:   How would YOU go about improving the cooling system on a 
Corvair engine, outside of the obvious like sealing and deflashing 
and bottom shroud removal and remote oil cooler etc?  We're talking 
improved hardware.   Ever give it much thought?

Remember, detractors, I'm attempting to milk the minds of those who 
are smarter than me.    Delete at your pleasure.




tony..