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Re: Oil Cap

To: On the Mark <otmc@bc1.com>
Subject: Re: Oil Cap
From: Trevor Boicey <tboicey@brit.ca>
Date: Thu, 23 Apr 1998 01:27:08 -0400
Cc: Triumph list <triumphs@Autox.Team.Net>
Organization: BRIT Inc.
References: <B0000005744@207.34.139.253>
On the Mark wrote:
> there any pressure requirements that I am violating by having the cap open,
> that would have led to my poor running?

  You just created a giant vacuum leak, no big deal. The cork suggestion
sounded like a good one.

  Your car has a PCV system which keeps the crankcase at a slight
vacuum. This does a few things, one of which is helps stop the car
from leaking.

  The real reason for this system is so that the nasty oil vapour in
the crankcase doesn't get released into the air, instead it is wired
to the intake and is sucked into the engine and burned.

  However, if you have no cap, you have a vacuum short circuit because
the vacuum lines to the carbs suck air from the crankcase which is
just sucking in from the oil cap.

  If you cover the oil cap with the palm of your hand temporarily,
the car should perk up again.

-- 
Trevor Boicey, Ottawa, Canada.
tboicey@brit.ca, http://www.brit.ca/~tboicey/
[ Seeking some miscellaneous MG parts, see the list on the web page... ]

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