Date:         Mon, 26 Oct 2009 19:43:34 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Charcoal Cannister Purpose
Comments: To: Michael Sullivan <sandwichhead@GMAIL.COM>
In-Reply-To:  <eccfedcc0910261412g72ffadfbj6b62d331a36d4e38@mail.gmail.co m>
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At 05:12 PM 10/26/2009, Michael Sullivan wrote:
>What is the purpose of this?

It contains "activated" charcoal, meaning it's been treated so as to
have an enormous surface area -- an acre per teaspoon or something
outrageous like that.  Fuel vapor from the tank is vented into the
charcoal, which adsorbs (like absorbs, but on its surface instead of
throughout) the gasoline vapor.

When the engine is running, it slowly pulls air through the charcoal
and into the intake tract, bringing with it the previously adsorbed
gasoline which is burned with the rest.

>  Any maintenance required?  Thanks.

In principle it should last forever -- no moving parts and no
chemical reaction btw the charcoal and the fuel.  Its connections
need to be viable of course.

Yrs,
d