Spyder/Corsa Cylinder Head Temp Gauge Thermistor

[LBC TITAN]

I believe I have solved my problem regarding the cylinder head temp gauge. I'm using an Autometer CHT Gauge along with an Autometer 2259 temp sending unit (thermister type). The gauge max's out at 340, too bad, but I'm only using it as a indicator and not as an exact temperture reading. What I mean by that, is that I'm watching for large spikes in temperture that can indicate a problem before a really big problem and shut the car down before then.

This combo was alreadyin the car when I bought, but the gauge stop working and was leaking some oil. So I bought a new Autometer gauge and sending unit, all for just $70.00. To check the reading on the gauge and compare it with the temp from the head, I also bought a infrared thermometer from Harbor Freight.

First thing I did was to test the infrared thermometer by measuring the temp of boiling water, water boils at 212F depending where you are, I'm on the coast. The infrared thermometer was only off by a few degrees which is okay with me.

I took the car for a spin to bring it up to normal operating temperture and pulled over to the side of the road with the engine still running to get a reading and it was showing a 10-20 degree difference. This is kind of hard to do while sticking your bare hands under a running Corvair the temp is very high, you don't want to have a baked hand.

If normal operating temp is 350-500 degrees it would seem I'm okay. I will do some more testing tommorow and see what kind of numbers is get. Now that I have some numbers to go by I can start figuring out how to lower the temperture, any suggestions would be appreciated.

[bbodie52]

At 340° F, the gauge you are using has an inadequate range for an air cooled engine cylinder head. VDO water temperature gauges have a maximum scale of 250° F. Their oil temperature gauge reaches 300° F, and their transmission temperature gauge reaches 400° F. But the model 310 901 cylinder head temperature gauge has a maximum capacity of 600° F, which matches the scale seen on the Corsa cylinder head temperature gauge. (I routinely see 400° on my 140 hp Corsa when cruising at highway speeds during the summer months).

Corvair Corsa Instruments

Unfortunately, it is my understanding that the VDO cylinder head temperature gauge has been discontinued, but is scheduled to be replaced with a new model by the summer of 2016. A copy of the old model instruction sheet is attached below, for your information.

[cad-kid]

Good job on trying some different methods

[Reindeer]

Has anyone tried the 10mm ring type CHT sensor, as mentioned in the flycorvair article? I'd like to have a working gauge, and if I can do it for $35 that would be ideal.


http://thesensorconnection.com/cht-sens ... -and-14-mm" onclick="window.open(this.href);return false;

[LBC TITAN]

You are correct that the gauge is not sufficient to read the temperture. One thing that I believe has been proven, is that I don't need the AC thermistor since I'm using aftermarket gauges.

So now I'm search of a gauge that can, a VDO or Westach dual CHT gauge should give me what I'm looking for.

At 340° F, the gauge you are using has an inadequate range for an air cooled engine cylinder head. VDO water temperature gauges have a maximum scale of 250° F. Their oil temperature gauge reaches 300° F, and their transmission temperature gauge reaches 400° F. But the model 310 901 cylinder head temperature gauge has a maximum capacity of 600° F, which matches the scale seen on the Corsa cylinder head temperature gauge. (I routinely see 400° on my 140 hp Corsa when cruising at highway speeds during the summer months).

Corsa Gauge Modifications.jpg

Unfortunately, it is my understanding that the VDO cylinder head temperature gauge has been discontinued, but is scheduled to be replaced with a new model by the summer of 2016. A copy of the old model instruction sheet is attached below, for your information.

[playerpage]

Well, there's this thing now. Came out in 2017---? I need a new thermistor and am considering it. NOTE--I haven't used it.

Advanced Cylinder Head Temperature Sensor byVairtrix

The CHT-100 is an advanced Cylinder Head Temperature Sensor for the Corvair Spyder and Corsa models. Designed as a direct replacement for the obsolete AC Delco Thermistor, the CHT-100 uses thermocouple technology for reliable and accurate temperature measurement over the wide range of temperatures experienced in the Corvair air cooled engine. It uses your existing Spyder or Corsa dash gauge for a stock look with upgraded performance.

The CHT-100 uses advanced digital technology to convert the thermocouple measurement to a constant resistance source, matched specifically to the Corvair dash mounted cylinder head temperature gauge. It performs sensor linearization using tables published by the National Institute of Standards and Technology (NIST). The CHT-100 includes Cold Junction compensation to maintain accuracy over a wide range of ambient temperatures. Finally, the output of the CHT-100 is matched to the unique non-linear response curve of the Spyder and Corsa dash gauges. The result is a sensor that outperforms the original AC Delco design and provides an accurate temperature report from 200 to 600 degrees Fahrenheit.

For more information on this product, visit http://www.vairtrix.com

[66vairguy]

The company did a deal with Clark's who now sells the thermister replacement. Unfortunately it doesn't come up in Clark's search. Call them.

[acarlson]

Clark's also sells the Vairtrix thermister:

http://www.corvair.com/user-cgi/catalog ... age=SUP-27

[bbodie52]

Tue May 01, 2018 6:01 pm


http://www.vairtrix.com/index.php#!/HOME

ABOUT VAIRTRIX

Vairtrix is an obsolescence management company dedicated to the preservation of classic vehicles.
Vairtrix’s principal architect has been a Corvair owner since 1973 and possesses over 35 years of experience in developing sophisticated military and automotive electronic systems with high survivability that are used in the harshest of environments. He is a former member of the Institute of Electrical and Electronic Engineers (IEEE), the Society of Automotive Engineers (SAE) and the National Defense Industrial Association (NDIA).

Re: Advanced Corvair Cylinder Head Temperature Sensor by Vairtrix

http://corvaircenter.com/phorum/read.ph ... 867,page=1


http://www.corvair.com/user-cgi/catalog ... age=SUP-27


Part number C1717: 62-64 TURBO CYL HEAD TEMP SENSOR *THERMO COUPLER - REPLACEMENT FOR THERMISTOR

Weight: 0 lbs 4 oz
Catalog Pages(s): SUP-27
Price: $ 149.95

Part number C1718: 65-66 TURBO & 140 CYL HEAD TEMP SENSOR *THERMO COUPLER - REPLACEMENT FOR THERMISTOR

Weight: 0 lbs 4 oz
Catalog Pages(s): SUP-27
Price: $ 149.95



Part number C10888: THERMISTOR ADAPTOR-THERMISTOR INTO 80-110 HP HEADS -- DO NOT OVER TIGHTEN

Weight: 0 lbs 2 oz
Catalog Pages(s): 51
Price: $ 12.60