Temperature Sending Unit (inline 6)

While I have a mechanical coolant temperature gauge mounted in one of the water jacket block openings, I have always wanted to add an aftermarket, calibrated (not just H_C) electric gauge using either the factory or aftermarket sending unit at the factory location (up by the tstat in the head).

Does anyone know if there is an aftermarket temp gauge calibrated to use the factory sending unit or has found an aftermarket sending unit/gauge combo that will fit in the factory location?

It looks like it could be (without pulling it and dumping coolant) 1/8-27 NPT.

 

Mmm. The factory gauge is electric, not mechanical. Is that what you mean? A mechanical temperature gauge is rather unusual - they exist, but not common.

Year? Engine is a 258? It would help to put that stuff in your profile and/or sig so we would not have to ask every time.

Look at the TSM for your year, and it has the calibration values for the factory sender. Match the aftermarket gauge to the factory sender.

 

The factory electric gauge (mounted in the speedometer) has not worked in 20 years. I added a mechanical gauge (many years ago) in the block water jacket opening. The calibration table you included matches my sending unit... My sending unit is good (runs around 33 ohms once warmed up).

I may not be looking in the right places but I cannot locate any vendor (Stewart Warner etc.) that publishes their calibration profile.

My solution was to replace the factory sending unit with an aftermarket gauge/sensor set and was wondering if anyone had ever found an aftermarket electric set that had a sending unit small enough to go in place of the factory sending unit..

 

Yeah, I looked at the Stewart-Warner catalog, and the info is not there. http://www.stewartwarnercanada.com/media/pdf/catalogs/SW-HDCatalog.pdf

They do have many different sizes for their sender though. Says the sender is 1/8" NPT - that's about as small as they get.

 

Just a comment - not sure you are up for this - if you have the gauge, say the Stewart-Warner of your choice, you can mimic the performance of the sender with a potentiometer. Set the pot to 73 ohms, and see what the gauge reads. Repeat for 36, 13 and 9 ohms. If the Stewart-Warner gauge reads the same temperature as the factory spec at those resistances, then use the factory sender. If not, get the Stewart-Warner sender.

 

I think I will give that a try first.
I have read various horror stories (on other boards) of folks either breaking the factory sensor off in the head or cranking down on a sensor (with the incorrect thread count/pitch) and cracking the casting..

 

http://civilianjeep.info/Strenk/Gauge web page/QuickFacts.htm

Some how I found this link.