<VV> Corvair a City Car / make it a Highway car

[Brent Covey]

The idea of Exhaust Gas Recirculation sounds good to me-

I have nursed a few extra miles out of old garbage 110's in what amounted to
parts cars with bad compression rings and tapered cyl barrels (pays to have
working thermostats!) that were doing that oil squirt thing out the dipstick
tube by plumbing the PCV foo-foo tube with a normal PCV valve directly into
the balance tube. This was done on engines in really appalling condition,
that could not have been driven without oil ejecting out the dipstick
otherwise. There did not seem to be any negative effects from doing this,
although I imagine the crank seal surfaces might be damaged, and that
crankcase ventilation wasnt all it could be... This subjects the crankcase
to manifold vacuum under all conditions, which isnt entirely desireable but
has some interesting side effects-

#1- No more oil leaks with a running engine!

#2- Free 'EGR' and idle stabilization

#3- Oil consumption dropped to practically zero even on engines with very
weak compression.

It was usually neccesary to make a loop of hose in the PCV plumbing that
reached high up by the plenum to preclude oil condensates from being drawn
into the PCV.

The blowby is essentially wet steam with a bunch of inert post combustion
gasses that works a lot like water injection. Because the volume of blowby
is proportional to engine load, under load or at idle you get more than
usual. This allows a little extra tolerance before ping under heavy
throttle, and tends to even out idle when a/c compressors are switching on
and off etc.

Although I wouldnt suggest this modification on an engine in good condition,
it kept a few old beaters running an extra year or two and demonstrated the
effectiveness of EGR on a Corvair to my satisfaction. Economy with these
engines was very good, although whether it was lower throttling losses or
just the lack of friction from the absence of close tolerance parts I cannot
say. I would regularly see mileage in the 26-27 USmpg zone around 55-60 mph
on premium gas.

A proper EGR system might be a pretty good thing from a fuel economy
perspective, some of the ~1975 model GM cars (Pontiac) has a EGR signal
amplifier built in that could likely be adapted to operate the Corvair
system if you tapped an EGR port into the exhaust system. I would imagine
the balance tube should be rerouted on the drivers side to enter under the
LH primary carb for best effect on 140's.

Brent Covey
Vancouver BC