Temperature Sending Unit Location?

pyroman

Founding Member
Jul 28, 2002
480
3
18
Ennis, Texas
So I've got a 302 in a 67 coupe. The intake I currently have has two holes in the coolant passages, one where the heater restrictor goes and the other towards the drivers side of the engine. This is generally where the sending units are located right? Well this particular hole is too small for the sending unit's threads. Right now I have the sending unit located right before the thermostat. Does it matter really what side of the thermostat I have it on? Where else could I put it?
 
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I have mine in the port on the front driver side near the distributor. I have an aluminum intake. What intake do you have? You may have to get a different sending unit with different threads or an adapter fitting.
 
I have mine in the port on the front driver side near the distributor. I have an aluminum intake. What intake do you have? You may have to get a different sending unit with different threads or an adapter fitting.

Mine is aluminum one too but it's an old one. A Weiand Colt 500. Know where I could get an adapter like that? I tried looking for other sending units with smaller threads but my first search turned up about zilch. My best guess is that the stock sending unit is 8 AN? and the port by the distributor on the driver's side is 6 AN.
 
The ports should NPT thread, I don't know the size of the stock electrical sending unit off hand, I believe it's the same size as aftermarket mechanical sending units and normally the port is larger so an adapter is used for the mechanical sender small to fit the larger hole.
If you use the port that is on the hose side of the Tstat you'll be reading the temp. in the rad. and not the engine basically. As the engine heats up the temp gauge won't change as the Tstat hasn't opened, when the Tstat opens the hot water will hit the sending unit and your gauge will jump up all the sudden. When it reads from the motor side of the intake your temp slowly rises and falls as the engine temp changes.
Jon
 
So I've got a 302 in a 67 coupe. The intake I currently have has two holes in the coolant passages, one where the heater restrictor goes and the other towards the drivers side of the engine. This is generally where the sending units are located right? Well this particular hole is too small for the sending unit's threads. Right now I have the sending unit located right before the thermostat. Does it matter really what side of the thermostat I have it on? Where else could I put it?

There were two size temp senders, you just need the smaller one. The electrical value was the same, either way.
 
The ports should NPT thread, I don't know the size of the stock electrical sending unit off hand, I believe it's the same size as aftermarket mechanical sending units and normally the port is larger so an adapter is used for the mechanical sender small to fit the larger hole.
If you use the port that is on the hose side of the Tstat you'll be reading the temp. in the rad. and not the engine basically. As the engine heats up the temp gauge won't change as the Tstat hasn't opened, when the Tstat opens the hot water will hit the sending unit and your gauge will jump up all the sudden. When it reads from the motor side of the intake your temp slowly rises and falls as the engine temp changes.
Jon

Oh yea, you're right about the sizes. And that's pretty much what I was thinking, I'll need to move it then.

There were two size temp senders, you just need the smaller one. The electrical value was the same, either way.

Hmm, where can I find the smaller of the two? Seems like the searches I've done have turned up one size only.
 
I remember seeing both sizes. I ended up getting the smaller sending unit to fit my Edelbrock intake. I think CJ shows pictures of them. If it turns out that the intake is an odd ball size and neither sending unit fits, then you can go to an auto parts store or hardware store and ask them if they have a fitting that could be used as an adapter. I have gotten alot of stuff like that at Car Quest. You will still need to figure out what size it is though.