<VV> Cylinder Head Temp Installation

[Sethracer at aol.com]

Technical tip for installation of Cylinder Head Temp  gauges. 
Over the years I have installed just about every type and brand of  
cylinder head temp gauge, from stock adaptations to aftermarket gauges. Aside  from 
the thermistor-type sender for the stock Spyder/Corsa dash gauge, most of  
the aftermarket uses thermocouples, bi-metallic junctions of dissimilar 
metals  that create a voltage when heated, to drive their displays. Being 
blissfully  unaware of the issues introduced by adding more junctions, my first 
non-stock  installation was in my Corvair powered Lola, where there was only 
room in the  dash for a single head temp gauge. So I installed two senders 
and switched their  outputs to select the left or right sender to display. I 
was likely reading  wrong numbers, but relative readings were what I needed, 
so everything worked  fine. Most of the aftermarket gauges use a 
thermocouple crimped into a ring  terminal that is designed to go under a spark plug. 
Although accurate, this  style adds a bit of awkward work while changing p
lugs.  In the past I have replaced the  spark-plug sized ring terminals with 
smaller ones and clamped the terminals  under socket-head screws replacing the 
original temp senders.  Doug Hargrove upped the ante by drilling  through 
the bolts and using a spring to push the “couple” up against the  cylinder 
head, for the fastest reading of temp changes. A pair of easily  available 
Cylinder head temp gauges are available from Westberg Manufacturing in  
Sonoma, CA., under the Westach line. They provide a very nice thermocouple  
mounting design that looks like it was designed for the Corvair. A machined  
fitting screws into the 3/8-24 stock machined hole in the turbo or 140 head,  
allowing the thermocouple to be placed up tight against the head, retained  
tightly in place but easily removable if you need to drop the motor out. A nice 
 product. If you want to use the gauge in an “other than turbo/140” head, 
you can  use the thermistor adapter from Clark’s. It screws into the stock 
3/8-16 threads  and presents a 3/8-24 thread for the Westach fitting.  
Another benefit from this application  showed up when I found the first few 
threads “missing” on one of the heads on  the race car. Since the regular fitting 
couldn’t work, I tapped the threads out  to a 1/8-27 NPT and used a simple 
pipe thread adapter to install the Westach  hardware. The thermocouple slid 
right in and bottomed into the head as intended.  Westach offers both single 
indicator and dual indicator gauges in their Cylinder  Head temp line.  You 
can find the  items at   http://www.westach.com/   If you want  help with 
part numbers or applications, just drop me a  note. 
Seth  Emerson