<VV> Fans of electric

[Padgett]

>  The simple fact of life is that no fan can develop enough pressure to 
> shove the required mass flow through the engine and there are no magic 
> unknowns that can make it otherwise.

Well, I am not so sure of that. Certainly we have come a long way in 
conductive coatings and design since 1965. Also the Corvair was designed to 
operate with crude baffles, a lot of flashing, and poor maintenance (late 
60s were the first to get 50,000 mile powertrain warrenties).

On the other hand an air cooled engine is going to have hotspots that its 
water cooled cousin will not. The SAE tests show the region where the 
thermocouple mounts runs 100F hotter than the area around the spark plug. 
This is not good but I suspect that better air flow management would help. 
A water cooled engine may run hotter on the average but would not have the 
extremes an air cooled engine sees.

Another factor is that the Corvair air flow is optimised to a certain 
extent to provide heat for the passenger compartment. Nothing wrong with 
that, just a fact. That is way the air flow control is on the output

Finally the alternators available to the corvair and the total power 
capability was restricted by concerns about the fan belt. I suspect this is 
why every other GM car with AC got at least a 55 amp alternator. The issue 
is that there is not as much power left over as there would be with a 
modern 100+ amp alternator that uses a serpentine belt. If someone wanted 
to be creative, replacing the alternator with an idler and driving a 
relocated alternator with an a/c fan belt would be a possibility. OTOH I 
have heard of an 80 amp alternator being used with success.

Now if you really want to go far out, the way to get max HP and minimal fan 
drag when not needed is to choke down the inlet. No need to worry about 
overspeed as you might with a turbo since it is locked to engine speed but 
with a choked inlet the power required to turn the fan drops. I suspect 
this was not considered because the Corvair was inexpensive and it would 
have affected the heater quite a bit unless other ($$) arrangements were made.

All of this would be wonderful for a back yard mechanic to tinker with but 
my life is just too full for the foreseeable future though I would love to 
see a redesign on the shroud to go with digital EFI and a computer 
controlled fan inlet. Would be great fun but I have had the new fan bearing 
assembly and carbs and 95 hp heads all waiting their turn for over a month 
now....

Padgett