<VV> Thermisters (Now plug depth)

[RoboMan91324 at aol.com]

Hello Craig,

I have always wondered if there is any issue with sparkplug thread depth when 
you use an under-the-plug thermistor.  Obviously, the sparkplug will sit a 
little higher in the hole by the thickness of the thermistor.  If any of the 
threads in the head are exposed, wouldn't there be a problem with carbon build 
up?  This could cause a problem if you ever remove the thermistor for any 
reason.  The carboned threads would cause interference with the plug that would now 
want to go deeper.  Also, if the plug is at all recessed in the plug hole, 
could this cause an ignition problem?  I understand that some plugs already have 
a depth problem even without the use of an under-the-plug thermistor.

Inquiring minds want to know.

Doc
~~~~~~~~~~
In a message dated 8/15/2005 7:52:46 AM Pacific Daylight Time, 
virtualvairs-request at corvair.org writes:

> Message: 7
> Date: Mon, 15 Aug 2005 10:36:32 EDT
> From: NicolCS at aol.com
> Subject: <VV> Thermisters
> To: virtualvairs at corvair.org, pp2 at 6007.us
> Message-ID: <158.56bb6e03.30320270 at aol.com>
> Content-Type: text/plain; charset="US-ASCII"
> 
> 
> 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.  
> <snip>
> Craig Nicol
>