Date:         Thu, 13 Mar 2003 13:01:58 -0800
Reply-To:     Tom Young <tomyoung1@ATTBI.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Tom Young <tomyoung1@ATTBI.COM>
Subject:      Some more on "measuring deck height"
Comments: To: type2@type2.com
Content-Type: text/plain; charset="iso-8859-1"

Hi all:

A while back I asked a question about a set up I saw at

http://home.hiwaay.net/~langford/corvair/valvejob.html

for measuring deck height using a dial gauge.  (The picture I'm referring to
is about 3/4ths of the way down the page.)

I thought perhaps there was some way to measure deck height directly using
this set up, i.e., without removing the dial gauge from its place at the top
of the cylinder.  As the author didn't explain how he used this set up I
asked the list and was told that the way it was done was to note the reading
of the gauge with the piston at TDC, then move the set up over to a flat
surface, take another reading, do a little math, and you've got it.  So I
thought I'd give it a try.

Well, I'm not impressed with the technique so far, but maybe I'm doing
something wrong and I'm hoping someone can provide some guidance.

First, the flat bar that spans the top of the cylinder and provides the base
for the dial gauge has a fairly narrow "foot" and I found it very
difficult - maybe impossible - to determine when I had the "foot" flat
against both sides of the cylinder.  I found that just a very little rocking
of the bar from side-to-side would move the gauge 8 - 10 thousands of an
inch without me being able to determine with certainty when it was "flat."

The problem continued over at my flat surface - a quarter inch thick piece
of plate glass - where "rock" and differences in pressure I'd apply to the
bar also cause the dial gauge to fluctuate fairly significantly.

Has anybody used this technique and can offer some tips?  Otherwise I'll
probably just go back to my flat bar and feeler gauge method.

TIA.
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Tom Young                       '81 Vanagon
Lafayette, CA 94549         '82 Westfalia
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