Date:         Sat, 26 May 2012 10:48:40 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Low Temp Radiator Thermo Switch "Better"?
Comments: To: pickle vanagon <greenvanagon@gmail.com>
In-Reply-To:  <CA+n284PiBDRPzJo1GuZ5HkFy8YKc6voS7Mdag2ibdAc_yqoZFA@mail.g
              mail.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 10:56 PM 5/25/2012, pickle vanagon wrote:
>This is a good point.  I hate how in new cars many of the gauges are
>actually idiot lights, in that they're stabilized at some fixed
>position within a very large range.  We should admit that new VW's
>seem to be like this too.

Been a long time since I've driven a new car more than a hundred
feet.  But w/regard to the temp gauges...the gauge indicates temp of
the circulating coolant inside the engine, whereas the fan operates
based on inlet temp at the radiator.  And with electronics you can
make a gauge say anything you please, so it's certainly possible that
a response curve has a big notch in the middle where nothing much
happens, to avoid exactly the sort of reactions we experience with
the Vanagon.*  But at least in the cars I'm familiar with, I have a
notion that the temp gauge stability reflects a requirement of an
open-deck engine for stable temps.  See
http://legacycentral.org/library/literature/deck.htm  for images.  A
die-cast engine has to be open-deck so the die can be extracted and
this leaves the cylinders with no support at the top where they meet
the head.  Our engines I think are effectively closed-deck because
the top of the cylinder seats into the head rather than just pressing
against it.

Yours,
David