I respectfully disagree that "the oil slows the rate it drops at." The purpose
of the air valves is to provide smooth powerful acceleration and they do that by
the use of dampers and dashpot oil to control the upward movement. The downward
movement is controlled by the spring between the air valve and the cover.
The "damper is single-acting, i.e. it is effective only for upward movement of
the oil column in
which it is immersed, the air valve (piston) falling immediately when the
throttle is closed, preventing an over-weak mixture being produce on
deceleration." (Haynes ZS manual).
Since the air value is pulled up by vacuum more air flow would equal more
pulling force, So Martin is right, a better breathing engine would require a
heavier oil in the dashpots...but not because it enriches the flow too quickly.
You would need heavier oil because the air valves would be pulled up (and out of
the way) too quickly and let in too much air which would cause a leaning of the
mixture. During acceleration you want the opposite...air valves rising slowly
so that less air gets into the mixture which gives you a richer mixture
(temporarily) for the power you need at that point. As you reach cruising speed
the valves reach their open (up) position to give you a leaner mixture for
economy.
Bud
71TR6 CC57365
71TR6 CC65446
66TR4A CTC57806
____________________Reply Separator____________________
Subject: That Dashpot Oil Thing Again
Author: "Arthur H. Smith" <arthurhsmith@compuserve.com>
Date: 04/19/1999 6:59 PM
Message text written by Martin Secrest
>I'm presuming a better breathing engine pulls the carb piston
at a faster rate than an unmodified one ... thus
enriching the flow too quickly? Heavier oil needed? Or does the
motor pull the piston more slowly? Hmm.<
NO..... the oil slows the rate it drops at.
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