<VV> Fuel economy improvements for your Corvair (NO CORVAIR)

[NicolCS at aol.com]

In addition to my list of practical (and well proven) things you can  do to 
dramatically improve the fuel economy of a Corvair, here's an additional  
benefit of those fuel economy modifications: reduced engine cylinder head  
temperature. Think about it: if a greater amount of the energy in a given amount  of 
fuel going to moving the vehicle (miles per gallon), a smaller amount of it's  
energy is lost to "waste heat".   Note how much smaller radiators  are on 
water cooled cars today in comparison to the old days.  My 89 K2500  has half the 
radiator my '78 had. 
 
Another little known fact - I've heard a dozen guys say that Corvairs can't  
tolerate the lean mixtures of today's fuel injection systems.  The wrong  
thinking here is that today's engines run lean; they don't!  There are two  things 
to consider: 1) A carbureted Corvair with stock cylinder heads has poor  
mixture distribution and a wide range of air/fuel ratios is present in and  among 
the cylinders.  The limiting factor for detonation is the  presence of "lean 
pockets" in the cylinders.  These pockets detonate under  pressure and there's 
our knock. Corvairs have to be jetted richer than necessary  to raise the 
fuel/air ratio of the lean pockets so they don't detonate. Many  modern engines 
are modified for squish and tumble and all are injected. A  port-injected 
Corvair engine with heads modified for squish and tumble will have  few or no lean 
pockets and is much more resistant to knock so you can run a  leaner jet 
without knocking. 2) The other funny little twist is that modern FI  engines run 
RICHER at cruise than in the old days.  Engines, since the  advent of catalytic 
converters, cruise at 14.8:1 while the cruise setting  of old was more like 
15.5:1.
 
It's hard to fathom why so many search for the holy grail of reduced head  
temps and improved fuel economy in wild things like electric propulsion or  
electric fans when there is so much proven stuff ready to go.  
MHO, Craig Nicol