<VV> PCV system on the Corvair

John O'Shea jco99 at cox.net
Thu Dec 16 18:57:25 EST 2010

Other than the air pollution thing, is there a downside to the road draft 
tubes that are standard on early EMs?
My 62 Monza had a road draft tube.  I drove the daylights out of that car 
and don't recall any oil leaks.
Sixty degrees and sunny in Las Vegas today.

----- Original Message ----- 
From: <Sethracer at aol.com>
To: <lechevrier at earthlink.net>; <virtualvairs at corvair.org>
Sent: Thursday, December 16, 2010 12:03 PM
Subject: <VV> PCV system on the Corvair

> In a message dated 12/16/2010 10:41:26 A.M. Pacific Standard Time,
> lechevrier at earthlink.net writes:
>>The  0.060"  hole gives lots of vacuum / draw!!    BUT....   The 1/2' tube
> to the filter housing is where fresh air  gets in when the engine is not
> running....and where EXCESS  blowby  escapes
> Those of your that want to hold to the company line,  be my guests --
> I'm not among this group.  Read anything on  positive ventilation of the
> crankcase, and it's benefits to the modern  motor, and then note
> definitions for "positive flow ventilation"  ...
> On the off-chance that we can call a Corvair motor a "Modern" motor 
> <grin>
> - I believe there are two distinct crankcase ventilation modes to  the 
> (PCV
> equipped) Corvair engine - I guess a third mode is "not running".  When 
> the
> engine is running in good condition and little combustion byproducts  are
> entering the crankcase, the orifice in the PCV tee is supplying main 
> engine
> vacuum to the crankcase - well, a bit of it anyway, through the tee, in
> essence  sucking the fumes back in under the carbs and into the combustion
> process. If  the crankcase fume output exceeds the capacity of that little
> orifice - or it  gets plugged up - the fumes travel up the tube into the 
> inside of
> the factory  air cleaner - where they also get pulled into engine for
> combustion. It would be  interesting to place an extremely sensitive 
> vacuum gauge
> on, say, the  oil filler cap, and see if there is any vacuum pulled at
> idle. It wouldn't be  much, but maybe it doesn't have to be much to do 
> it's job.
> Except for the  tendency for the feeder tubes around the fan to get 
> plugged
> up with carbon, it  is a pretty decent system. I make sure they are 
> working
> okay on my cars. The  system, unless it gets completely plugged, should
> always keep pressures from  building up and causing oil leaks.
> Seth  Emerson
> C's the Day! - Corvair, Camaro, Corvette
> San Jose,  CA
> _______________________________________________
> This message was sent by the VirtualVairs mailing list, all copyrights are 
> the property
> of the writer, please attribute properly. For help, 
> mailto:vv-help at corvair.org
> This list sponsored by the Corvair Society of America, 
> http://www.corvair.org/
> Post messages to: VirtualVairs at corvair.org
> Change your options: 
> http://www.vv.corvair.org/mailman/options/virtualvairs
> _______________________________________________ 

More information about the VirtualVairs mailing list