Moving the temp sender

[melloelky]

and the results are?...

Hairdryer..

 

[pontiacgp]

Hairdryer..

I saw that....a precision tool...

 

[fleming442]

If you have the flowing locks of Stacey David, a hairdryer is a must have.

 

[gnvair]

I just went through this on my 78. The new heads had the 3/8" npt holes in the heads. The temp gauge worked fine with the original 1/2" npt sender. With the 3/8" one it would not move off of cold. I tried 3 different sending units with the same result. I compared the sending units and the 3/8" works off of a different range than the 1/2" one. The gauges on the 80-up must also be calibrated differently.
I ended up using my original 1/2" sender in the tapped hole to the left of the thermostat housing on my Performer RPM intake. It works fine now.

 

[xylorex]

I recently purchased one for my build and wanted one with a blade connection too, what I had read was that the ones with the blade are for cars with an idiot light instead of a temperature gauge.

Have any of you heard of that, or is that just BS?

 

[pagrunt]

I recently purchased one for my build and wanted one with a blade connection too, what I had read was that the ones with the blade are for cars with an idiot light instead of a temperature gauge.

Have any of you heard of that, or is that just BS?

The '80-'88 3/8" NPT gauge senders have both the button & blade. I have the original button type from my '86 parts car & a blade type (Wells) from '93 when I put gauges into my '81. Believe most if not all current production ones will be blade.

 

[5spdCab]

Yes you can, that is what I did with mine.
Also, I put three 3/32 holes in the thermostat flange to allow water flow while warming up the engine. It was a suggestion that I read in one of my car magazines a couple of years ago. It only takes a couple extra minutes to warm up, but there is no cold water shock to the engine block.
If you do add the small holes to the thermostat, be careful not to make them too large, or too many of them. I went through 3 thermostats before I got it right.
The small holes also allow the temp gauge to receive info from the sending unit before the thermostat opens.

Adding in a couple of pics.
The sending unit for the mech temp gauge, and an early failed attempt at putting the holes in the thermostat. Too many holes, and too large as well. With that many large holes, the engine never got up to temp high enough to use the heater at a comfortable level.

 

[gnvair]

I have several NOS GM sending units in the 3/8" size if any one is interested.

 

[Wageslave]

Adding in a couple of pics.
The sending unit for the mech temp gauge, and an early failed attempt at putting the holes in the thermostat. Too many holes, and too large as well. With that many large holes, the engine never got up to temp high enough to use the heater at a comfortable level. View attachment 142430View attachment 142432

You would probably want one 1/16th inch hole in the thermostat.

That being said, can you use the port in the front drivers side corner of the intake? That would be on the correct side of the thermostat. It still wouldn't be as accurate as the head, but in practice it is not a big deal either way.

 

[rogus]

and the results are?...

Tested two senders. One for a 79 Elky and one i had used in my 76 Chevelle. Neither started out with as high a resistance reading as on the chart but both dropped down to 177 ohms after being heated.