MTFCA Forum

I have a ‘26 Ford Model T coupe and am interested in installing a temp gage inside the car with the sending unit inserted in the return radiator hose. Has anyone done this and what was the resulting benefit?

acereske wrote: ↑

Thu Oct 14, 2021 12:44 pm

I have a ‘26 Ford Model T coupe and am interested in installing a temp gage inside the car with the sending unit inserted in the return radiator hose. Has anyone done this and what was the resulting benefit?

I have not done it, but I have used motometers. The only real benefit might be peace of mind? The downside might be that its readings might be something to needlessly fret over. The only temp gauge I use anymore is the overflow tube. If steam is coming out of it, something's wrong. If not, we're all good.

This would be period correct and excess to my needs. To install the sender, ypu can use a model A lower radiator tube, or drill and tap one of the T inlet or outlet casting. I’ve seen guys install in a soft plug hole, too. kISS

Hi Al,
Yes I use a SW mechanical gauge in the return pipe. The thing to remember is that this is the water coming out of the radiator and therefore cooler than the engine temperature. You need to establish the differance between the water coming out of the engine and the water going back in and add that to the gauge reading. A infared thermometer works good for this and has many other uses.
Craig.

First try was with the Model A inlet that has the thread port. But that only read the cool motor
Then mounted to the upper outlet, that let the meter read correctly. At norm temp when running at tour speed, not fast.
Fuzzy photo from running.

But at extreme speed, running with the modern traffic on 4 lane, likely doing 45mph + , the meter showed the work the engine was doing, generating a lot of heat from those hot pumping pistons

Other than using a MotoMeter and if the radiator isn’t gurgling or not getting really hot your OK. To me once you have a heat gauge of some sort in your car you would wind up watching it all the time. I guess Ford thought your amp meter was enough to be concerned about when he started to install them in the late teens!

Coolant temperature gauges are normally installed at or near the water outlet. It's possible to have a cool inlet temperature reading with a hot or even boiling engine. A clogged or frozen radiator will do it. A low water situation could do it.

I installed a temperature gauge in the water outlet on my speedster very similar to how Dan did his. I had an old aftermarket water pump housing similar to a Nims pump. It was missing the shaft and impeller so I tapped the hole and installed the temperature bulb. Seems to work well.

I went for a drive this afternoon with temperatures in the mid 80s F. Car runs about 200 F indicated at the water outlet. I pulled over and stopped after about 10 miles of running at 45-50 MPH with a good hill climb included. After about 5 minutes, I could put my hand on the water inlet pipe comfortably. The engine and upper radiator tank were still way too hot to touch, let alone grasp and hold.

No disrespect intended to anyone, but why would you put a temperature gauge in the engine inlet hose/pipe? This would give the driver no useful information as to the actual engine temperature.

For the lowest inlet temperature obtainable, make sure your radiator is completely clogged.

I think Ed Fuller wins for the perfect install. JMHO. Great idea to use one of those water pump castings

I have, what looks like, a NOS Motor Meter that is to be installed on the dash next to the switch. It has the heat tube and light wire. The face is like the one illustrated. If you or anyone is interested, email me.

Darel

Dan & Ed have the right idea if you can do that. if not the lower tube will give you correct info for the water coming out of the radiator. If you know the differance you can calculate the temp in the engine. If you are waiting for steam to tell you have overheated the engine then the # to AAA will come in handy.
Craig.

I drilled & tapped the rear freeze plug (or whatever folks call them) for 1/2 in. pipe on my Racer for a mechanical gauge works great !

Your greatest heat of true engine temp is here. The dead engineer in the picture said so!

Hank

Steve is that the Rajo engine? Not sure how the water circulates in a Rajo but in a stock T that would be only a 25% improvment in the inlet pipe sending unit. Hank that does not look like the smartest engineer on the prodject. I don't think this is helping Al.
Craig.

Yes it is Craig - I'm running a rather stout water circulator to assist in water movement through the head and I use "stick-on" Caterpillar heat indicators in different areas to double check.

If you have a good radiator, you don't need a temperature gauge or a water pump. Why waste your time?

My speedster body was on another chassis before I bought it. It had holes in the dash for three gauges. I installed the water temp gauge to fill one of the holes.

Went on a tour yesterday, some of the rout was on a highway with a 65MPH speed limit so the tour speed was between 35 & 45 MPH with a Temp. of close to 100* by the end of the tour. The first thing I noticed was my motometer no longer works. Engine never got up to 200* by the gauge it was nice to know under those conditions. Steve would like to know more about the Caterpiller stick-ons They would maybe solve the the discusion. And help with these issues. Have a friend with a T-Go head and had to put a circulation assist on it.
Craig.