With the vacuum side of the PCV (sic) valve plugged you will not be getting
any crankcase ventilation at all, which is a Bad Thing. Providing an open
tube down by the pan - a 'road draft' tube - which is what the earliest Bs
had might give some ventilation under some conditions, but even less than
originally, as the other end of the ventilation system on those cars was a
hose from the rocker cover to the air cleaner giving some suction. Even
that was considered inadequate (as well as sucking unfiltered air into the
engine), hence the PCV valve, which proved to be failure-prone and so the
much better carb ventilation system was introduced shortly after.
A ruptured valve will upset your mixture significantly (and probably
increase oil consumption), a correctly working valve will make little
difference as that is the purpose of the valve. If you remove the oil
filler cap and unblock the vacuum and you get a big change in idle, possibly
stalling, then the valve looks bad. On a working system the change in idle
should be minimal, with just detectable vacuum felt when placing the palm of
your hand over the oil filler hole. With a bad valve the vacuum will
probably try and suck you into the engine.
A *working* PCV valve is a positive (ho ho) benefit!
PaulH.
----- Original Message -----
From: "Mike Duvall" <duvallcom@sbcglobal.net>
To: "mgs" <mgs@autox.team.net>; <mg-mgb-list@yahoogroups.com>
Sent: Sunday, February 06, 2005 5:47 PM
Subject: [mg-mgb-list] PVC valve
> I discovered the vacuum side of my PVC valve has been intentionally
> plugged on my B.
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