<VV> Corvair Fan

[Crawford Rose]

I recall that Chevrolet stated that the fan redesign was to eliminate belt retention problems arising from heavy steel fans only, not to enhance cooling. I am not aware of any publication that claims that the fan was redesigned to improve cooling only to reduce inertia on changes of engine speed. The design of the original fan was conventional to the Porsche and VW fans in use at that time. Therefore, the supposition that the fan as designed (or even as redesigned) is inadequate is not a well founded premise.  Is it not more correct to state that burdensome air conditioning condensers, turbochargers and large valve heads are inadequate for the small Corvair engine? Why fuss with designing a new fan when a "better" cooling system of air and water jackets for liquid cooling could easily be designed but then, it is no longer the Corvair cooling system. I never had a problem with my 64 Spyder's cooling system which worked as designed, at speeds of up to 90 mph, for 124,000 miles.

Finally, what was so cheap about the cooling system? The total cost of all shrouds, seals, parts, and fan (itself $6.25 when minimum wage was less than $1.00) was $85.56 in 1960. The engine in a crate was 450.00. The cooling system was simplified thereafter to include bilateral thermostats damper doors, probably for no significant cost savings.

Crawford
  ----- Original Message ----- 
  From: JVHRoberts at aol.com<mailto:JVHRoberts at aol.com> 
  To: crawfordrose at msn.com<mailto:crawfordrose at msn.com> ; virtualvairs at corvair.org<mailto:virtualvairs at corvair.org> 
  Sent: Sunday, July 10, 2005 2:39 PM
  Subject: Re: <VV> Corvair Fan


  140, turbo, and air conditioned Corvairs have inadequate fans on them.
  Chevy designed the cooling fan to work, and do so as cheaply as possible. The 64 and later mag fan is die cast, and its shape is determined by its compatibility with that manufacturing process, NOT cooling and HP requirements. Magnesium was chosen because Chevy recognized there was an inertia problem, and swapping magnesium for aluminum meant less mass, more stiffness, and a fan that wouldn't 'ring'. But it is NOT the best way to blow air through an air cooled engine.