<VV> Corvairs and smog - Long

[Sethracer at aol.com]

It is likely that our Corvairs will someday be restricted in  general 
usage, unless they can somehow be modified to produce less emissions. It  will 
likely be a restriction like several insurance companies place on yearly  
mileage limits. This is not to start a debate about the possibility of such.  
This is just a discussion of possible avenues of approach, should that day 
come.  The modern car is treated on a holistic basis. All parts are evaluated 
for  their emissions, including paint, upholstery etc. But the power system 
emissions  are the main focus of the regulators and that is what I want to 
discuss. As  several people have mentioned, the design of the combustion 
chamber on the  Corvair head was state of the art in 1955. The Semi-wedge chamber 
of most  Corvair motors is, at least predictable for emissions. Air cooling 
of the heads  and cylinders adds a few extra variables into the mix, as hot 
spots and quick  temperature changes do not have the luxury of the liquid 
cooling "heat  sink" to mitigate and absorb that heat. It will stay hot until 
another  cooler blast of air drops by to pick up that heat and carry it 
away. The Corvair  cooling system, as designed, (if maintained), can cope with 
most conditions.  Ignoring racing and possibly extreme 110+ degree weather 
conditions. Our concern  has always been to keep overall temperatures down in 
the "happy" operating  range. With newer emission systems, that goal will 
change to keeping the motor  within a very tight range of operation to make 
adequate control of  emissions a probability, if not a sure thing. Even if 
the goals of the  regulators are set at reasonable levels, I am reasonably 
sure computer control  of the ignition and fuel system will be needed. The good 
news for us is that  these systems have, over the last 25 years flooded the 
aftermarket and the  replacement market with inexpensive hardware, and, 
over the last 10 years, with  programmable electronics to connect and control 
the cheap electronics. The  focus of most of the aftermarket EFI suppliers 
has been on increasing power  and driveability (compared to carburetors) and 
only on an ancillary basis  mileage and emissions. That may have to change. 
In the past, only people  interested in better power and performance were 
willing to go through the effort  and spend the money to modify the car to the 
extent needed to reach the  goals. That will change. I don't think that the 
Corvair engine, even  with every bandaid available, can reach the low levels 
of emissions which  are commonly available on new cars today - but they 
probably won't have to  do so. I believe that a Corvair engine in good 
condition, with a properly  programmed, electronically controlled fuel and Ignition 
system, and a  properly installed catalytic converter ,could meet the test 
levels of  commonly available and currently certified cars from the 90's. If 
our cars met  those goals, and passed testing at that level, the authorities 
should have  no complaints about us continuing to use our cars.    
Once again, I  am not trying to start a debate over whether smog standards 
should be applied to  old cars, I am just talking about possible ways to 
meet those  standards. 
 
How about a  140 Corvair motor, with 4 throttle body injectors mounted 
where the Rochester H  series carbs are now, a waste-spark ignition system 
triggered by a wheel on the  rear balancer, A big-single exhaust system with an 
appropriate Converter  mounted and shielded, along side the right head, as 
far forward as possible,  with a short muffler following it. The exhaust is 
complete with an appropriate  wide-band O2 sensor installed, providing 
feedback to the ECU which controls both  the ignition timing and the mixture 
provided the Fuel injection system.  Sensor inputs from incoming air temp, engine 
temp and others. An OBD2 systems  could be installed to provide driver 
feedback as well. 
 
So - who will be the first to build one of these? Or has it been done  
already - Completely.


Seth Emerson

C's the  Day! - Corvair, Camaro, Corvette
San Jose, CA