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

[NicolCS at aol.com]

Any number of Corvair vendors can handle the work and the development  work 
done by myself and many others is well documented in Bob Helt's book "The  
Classic Corvair". At a minimum, Wheelerizing, Ray Sedman, Larry Shaprio, and Bob  
Coffin can handle these modifications or you can do them yourself (except the  
milling) following the information in Helt's TCC. 

 
In a nutshell:
Inlet ports nothing or optional polish.
 
Exhaust ports: ports-nothing, exhaust system: 140 duals minimum or  
preferably headers.
 
Chamber: remove gasket step, increase remaining area to 49-50ccs give or  
take depending on how oversize your pistons are (target 9.25:1 compression  
ratio), unshroud intake and exhaust valves, remove sharp edges.  An  alternate 
approach is to have the pistons cut under the chamber to get back the  lost 
chamber volume and then unshroud valves and remove sharp edges.  Sharp  edges 
include: spark plug threads, chamber perimeter by head gasket, use of  copper head 
gaskets (blunt edge). Index spark plugs (or check  index)
 
Head gasket: .032 copper.  Check deck heights and evenly shim  cylinders if 
needed to get the least on a side up to .000 deck height.
 
Optionally, you might want to install pushrods that are shorter according  to 
the amount removed by milling the heads.  This will regain optimum  rocker 
arm geometry.
 
I have done this many times, the most radical was a 10:1 110 in a 65  
Greenbrier (last owned by Gerry Broyles of New Mexico). That one was a real  honey 
and the high compression wasn't a problem at all on goo premium  fuel.
 


How do we do that? Where do we find info on how to modify the inlet  ports 
and chamber to get the proper squish, tumble and swirl?
Chuck  S