Date: Mon, 7 Aug 2000 09:04:26 -0400
Reply-To: David Beierl <dbeierl@attglobal.net>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Beierl <dbeierl@attglobal.net>
Subject: Re: Refrigerator doesn't work yet.
In-Reply-To: <v04010501b5b40fca279f@mars.netspace.or.jp>
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At 04:17 8/7/2000, Yoshi wrote:
>Then, I discovered two wonders. "Inlet-pipe hole" & "Alloy foils".
Wonders indeed!
>Do these have any meaning?
The piece of foil over the hole in the side of the burner tube has meaning
-- the previous owner was experiencing a lean mixture -- too little gas for
the amount of air -- and applied the foil to allow less air. Usually a
lean mixture is indicated by the flame lifting away from the burner and
making more of a "rushing" sound than usual. A rich mixture is indicated
by yellow tip on the flame.
It could be that either a restricted gas metering orifice (the burner tube
fits over it at one end) or too-little pressure from the regulator could
cause this problem. The previous owner was obviously having problems -- I
would certainly check the regulator pressure and adjust if necessary, and
clean the orifice with multiple applications of alcohol and compressed air.
For working with the flame, you can burn the flame in the open combustion
box to observe its characteristics, then seal the box when you are
satisfied. The flame should burn quietly and colored only blue (possibly a
touch of clear orange from impurities). If there is any yellow like a
candle flame, the mixture is too rich. If the pressure and the orifice are
correct the flame should burn correctly at elevations up to perhaps 500
meters? At higher altitudes it may be necessary to reduce the gas pressure
by several cm or use smaller orifice which is unfortunately not available.
To measure gas pressure, professionals use a very sensitive meter as the
pressure is very low -- but you can do as well with a two-meter piece of
clear vinyl tubing. Form the tubing into a U shape and put in enough water
to be 50 cm high in each of the vertical legs. Apply and seal the tube to
the regulator output, turn on gas and measure the *vertical* distance
between the two water surfaces. It should be 28 cm. If it is too high and
you reduce the regulator adjustment, you will have to let some gas escape
before taking another reading, so in that case it is better to reduce the
setting very much and then gradually increase it to the correct reading.
I did not see the other piece of foil in your pictures.
The hole in the inlet pipe is simply bizarre and will cause the flame to
instantly blow out whenever a wind strikes the side of the van. The entire
burner system air supply must be sealed except for the inlet and outlet
holes directly at the vent fitting in the side of the van. To close this
hole I recommend (if it is available) a thick aluminum foil with adhesive
backing, used in this country for auto body repair. Two or three layers of
that would make a durable patch -- even one layer would work but it would
be easily pierced. The inlet pipe does not get very hot and the adhesive
should work ok. The seal must be complete, however -- be careful not to
get a fold in the foil.
david
David Beierl - Providence, RI
http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"
