<VV> Thermisters

[NicolCS at aol.com]

AC no longer manufactures the thermister but they seem to be somewhat  
available used; usually trading for $75 give or take.  There are no direct  
replacements. Many EE-types have investigated substitutes.  Lew Richel  (San Diego) 
sells a rough substitute that provides a reading on the gauge, but  it's not 
accurate.  He includes a conversion chart.  Clarks  occasionally has new 
thermisters and their price is $250 or so.  VDO  and Westech both make CHT gauge 
setups.  I'm not familiar with the Westech  sender but the VDO sender attaches 
under a sparkplug.  The VDO unit  provides accurate readings at the plug but these 
readings do not seem to  correlate to what we see with the GM hardware.  The 
rub with available  thermisters is that the are soldered internally where the 
OE piece was  crimped to take the expected 600 degree gauge maximum.  
 
110 heads do not have a place to directly install the thermister. Clarks  
makes an adapter that provides the proper threads and due to it's installed  
height, it provides adequate depth for the thermister as well. In my younger  
days, I had the nerve to drill 110 heads deeper and rethread the hole for the  
required fine threads.
Craig Nicol

<snip>My understanding is that the transducer  for the Cyl Head Temp gauge 
used in 
the Corsa dash is no longer available  (NLA) but there is a substitute (do 
the LM 110 heads have a place for it ?)  or  there is a spark plug mounted 
transducer  ? - does someone  have a source for either ? The Clark catalog 
seems a bit vague and trying to  get everything in place for a conversion.

Padgett  <unsnip>