<VV> gas in the oil is probably a leaking fuel pump

[N. Joseph Potts]

Fuel gets into a Corvair's crankcase through leaking float valves in the
carburetors, too, ESPECIALLY when the vehicle has an electric pump that can
run when the engine is not running. I've seen this with my own eyes, not
only with the electric pump, but with a mechanical pump on a 140hp engine
(four float valves to leak).

Joe Potts
Miami, Florida USA
1966 Corsa coupe 140hp 4-speed with A/C

-----Original Message-----
From: virtualvairs-admin@corvair.org
[mailto:virtualvairs-admin@corvair.org]On Behalf Of kenfran@comcast.net
Sent: Wednesday, January 26, 2005 4:10 AM
To: virtualvairs@corvair.org
Subject: <VV> gas in the oil is probably a leaking fuel pump

I had the same thing happen to my 1987 Dodge Caravan. The mechanical fuel
pumps are diaphragm type pumps, and the diaphragm is moved up and down by
something like a lifter that works off the end of the cam. If the diaphragm
breaks (and remember that it is just a piece of neoprene that is flexing,
pushing the fuel in and out of the pump, at the same speed as the engine
RPMs, for thousands of miles) the fuel is obviously gonna squirt past into
the engine case. Your oil is not going to lubricate very well when thinned
by gas. (Might clean out some of those blocked oil galleries, though <grin>)
This is one reason for using electric fuel pumps. Also, if you change over
to an electric pump, it is a reason NOT to use the original fuel line
through the mechanical pump, even though the valves on the mechanical pump
will still allow it to work. But if the diaphragm leaks, you are still gonna
get gas into the oil. My Corsa came without a fuel pump or master cylinder,
and one of the first things I'm gonna do is put on an electric pump.

Ken Franson
CORSA & Arkansas Corvair Club member
1965 Corsa 140
1966 Monza 110 auto 4-door