<VV> Thermister Swap?

[Bryan Blackwell]

So, based on Frank's info can anyone here verify if an 82 ohm resistor in series with the Rochester thermistor work ok with the stock gauge?  I have a 110 in the '66, it would be nice to use the head temp gauge (I'm aware the threads are different).

--Bryan

On Aug 29, 2014, at 10:57 PM, Frank DuVal via VirtualVairs <virtualvairs at corvair.org> wrote:

> Let's see where to start, OK, an article on troubleshooting a Corsa gives:
> 
> With the engine cold, the reading should be 5000+ ohms. An engine running at normal temps can range from 500 (300F) to 750 (225F) in Ohms. Lower than 500 ohms simply means your engine is getting hotter than normal. Running the engine for a good 20-30 min usually hits 300F or so, but is stable at that temp. A lot of stop and go driving, heavy traffic congestion may force it higher. Running the engine for only 15 min will barely get the temp to 200F (1000 ohms) and your gauge may not even reflect it. Ohm readings of 310 or less indicate the engine is reaching 400F or over. Less than 200 Ohms indicates engine temp is 450F +. The range of the gauge is from 200F (1000 ohms) to 600F (100 ohms). At 5000 Ohms, the temp is 70F. At 575F, the alarm will go off.
> 
> And I found this info on  robinsonheli.com   for CHT probe 3080-38:
> 
> 200 °F is 745 ohms
> 475 °F is 38 ohms
> 500 °F is 32 ohms
> 
> So, it is a thermistor, but the range looks really off at higher temperatures. Somewhat close around 200 °F. At normal driving temperatures, the gauge will read over temperature.
> 
> Frank DuVal