The Stovebolt Site Forums The Shop Area Engine Shop Install an electric heat gauge on my 1950 216

Hi all! My original temp gauge sometimes doesn’t go up gradually as it should. It’ll read cold, then suddenly jump and indicate operating temperature. Installing a new gauge is beyond my skills. So, can I put an electronic heat gauge in its place mounted under the dash? Thanks for the help. It’s a 1950 216 engine

It would probably be easier to replace the gauge and sending bulb with an original type instead of going electric. One issue with electric gauges is that finding them in 6V is going to be pretty hard.
Most likely the capillary tube to your gauge has been kinked, which would affect the gauge action. Or the needle is physically hanging up. If you can remove the gauge cluster and check that you should be able to either free it up or find a replacement original (try the swap meet here for that.)

I neglected to mention that it is 12 volt. I checked the tube and see no kinks. I’ll look closer though. I have no idea how to get the cluster out of the dash. I’ll check that out too. Would rather just install an electric one if I can though. Thanks for your response

12V gauges are readily available. The biggest concern would be finding the compatible sending unit that will fit in the head of your 216. I believe it's not a standard pipe thread tapping. Figure that out first.

Ok! Thank you

I had the exact same condition on my truck just before I started bodywork two years ago. My plan is to change the thermostat first, because it could be hanging up. Much easier and cheaper and it may just solve the issue.

Looking at pictures of the 216, the temp sender is at the back on the drivers side of the head. There is an adaptor that screws in to the head that holds the capillary tube bulb. Remove the bulb nut and original pieces, then remove the adaptor. Your electric gauge should come with the right fittings to screw into the head. The electric sender needs a good ground, so go easy on the teflon tape.

Drain the coolant down below the head hight, no need to drain it a out.

To test your OEM gauge, pull the bulb out of the engine and place in a cool water to get any heat out of it. Then take a heat gun or hair dryer on low heat and slowly heat it up. If your gauge tracks eratic, go the electric route, but if it acts normal, check thermostat, radiator, and/or water pump for any issues.

I just looked at the sender on my truck (engine is out and it's just hanging there.) It sure looks like a NPT fitting, although it may not be tapered. It is the same thread pitch as the same size pipe plug I held against it. The seal happens when the threaded fitting pushes the flange of the bulb against a shoulder in the head. So likely you'd need something that seals against that same shoulder.

The original sending unit threads directly into threads cut into the cast iron of a 216 head. There is no bushing.
If a newer 235 engine is used in an AD truck, a brass adapter bushing is needed for the AD sending unit because the later 235 heads have a larger hole than what is in a 216 head.
This larger hole in the later 235 is there to accommodate an electric sending unit which is larger than a 216 sending unit.
I doubt if one would have much luck finding an electric sending unit small enough to fit in the smaller hole in a 216 head.

Well, sorry about that, I looked for a long time at the pictures. Is there any room on the thermostat housing to drill and tap a pipe fitting hole? I had some electric senders that were 1/8" pipe threaded, guess the size depends on the gauge manufactorer.

The thermostat housing is not a good spot for a temperature sender. An 1/8 NPT sensor could be adapted to the original spot on the head.