MTFCA Forum

Has anyone added a coil of copper wire or a spring to the bottom of their Moto meter so it actually extends into the radiator water and registers properly?
The 24 Coupe I’m working on now has a flat tube radiator and cools so well that the water level never comes up high enough to touch the Moto meter and I just don’t get a decent reading. The meter works fine dipping the lower part into hot water on the stove so I know the problem does not lie there. Thanks

I don't think the motometer needs to have an extension that actually reaches the water. If the coolant apporoaches the boiling point, live steam will communicate the heat to the motometer. Your car may simply be running in the "cold" range on the motometer scale. A Model T with a clean cooling system and a good flat tube radiator will run cooler under most any conditions than a stock T would run. Modern gasoline allows advancing the spark more, and most Ts don't see much service in mud or sand like they once did.

Notice where the overflow tube is on the radiator? As the coolant expands it reaches that level and when it cools it contracts to the level it is when you check it. So if you have the proper fluid level in the radiator, the motometer will tell you when it gets too hot.
Norm

Moto-Meters don't read water temp, they read the air above the water level. If your water temp is too low, you may need to add a thermostat or block off part of the core. If you want to read the water temp, you would need a different temp. gauge installed in the neck on the head or upper hose. If it is a reproduction Moto-Meter, most are not known for accurate readings. Using a point and shoot temp gun to check, would give you a better idea what is going on.

Hello.

I am also wondering that the motometer is so far above coolant level, so I added a lower extension. Though, I haven't used it, I spent second half of this year with fixing the clutch, etc... So I had only a short drive and one run inside the garage. Works well.

What I did was:
I need to say in advance that I do not have a tapping tool of right size, in Europe imperial threads are a bit problematic.

1. I took a piece of copper pipe, easily sliding over the motometer tapping.
2. I used a metal saw to make a 1 inch cut in length direction - only on one side, not through both opposite walls.
3. Now I compressed the pipe by hammering it around a metal rod being a little bit thinner than motometer, until this slot was closed.
4. Now try if the pipe is sitting loose on the thread. If yes, back to 2. ... If it sits strong and needs to be twisted onto the tapping, it is fine (will not be vibrated off and drop into the radiator)

This way I prevented any damage to the (expensive) motometer, my extension ends 1/2" above bottom of upper radiator chamber. The extension can be removed whenever I want.

This morning I ran the T for 10-12 miles and even idled it with the spark retarded trying to get it to over heat a bit and 160 degrees was as hot as I could get it using a meat thermometer in the neck of the radiator. Outside temperature was 65 F.

This ‘24 T already had a water pump installed so I am installing a 180 degree thermostat tomorrow and already have a infrared thermometer on order.

Mark is on the mark.... Motometer reads water vapor temp inside the upper tank area.

Info from the horse's mouth

160 F is too cold. Be sure that your radiator is actually properly filled after adding a thermostat. Some thermostats are air tight when closed, or very nearly so, and they will prevent completely filling the system with water by trapping air in the cylinder head. Many thermostats have a small bleeder hole that allows air to pass when the thermostat is closed. The hole, if present, is usually very small and it can take a while for air to work its way past. I have carefully drilled a larger hole in thermostats to allow air to escape and to assure that hot water reaches the thermostat's sensor in a timely manner. This has to be done very carefully to avoid damaging the working parts of the thermostat or creating a condition that could lead to it sticking. A hole up to about 1/8" will have no material effect on the thermostat function, and will allow trapped air and steam bubbles to pass.

I think the water pump is the problem. The original thermosyphon system moves the water as it heats up in the engine. It then settles down to the bottom as it cools and continues to circulate according to the temperature of the engine. A water pump will continue to circulate the water even before it gets hot and so, especially in cool weather will never warm up. When I got my first T, someone before me had placed a water pump on it and we drove up into the mountains on a cool day. When we stopped for a break, others were standing in front of their radiators to keep warm. Mine was still cold. Later took off the water pump, no more problem.
If you want to continue with a water pump, you need a thermostat to keep the water from circulating until it reaches operating temperature.
Norm

Since I see no listing in some of the major parts vendors sites I suppose there is no source for replacement thermometers for the Boyce units?

Michael,
Correct, there are no replacements. Your first post stated it worked on the stove, it either works or it doesn't. Any air bubbles in the red, or red stuck at the top, or large gaps in the red, can be corrected with some simple procedures discussed at length in some older posts, alternating heat, cold, and bumping with a rubber mallet.

Get rid of that waterpump! You obviously don't need it! 15 million T's where made without them.

Humblej wrote: ↑

Fri Nov 05, 2021 5:03 pm

Michael,
Correct, there are no replacements. Your first post stated it worked on the stove, it either works or it doesn't. Any air bubbles in the red, or red stuck at the top, or large gaps in the red, can be corrected with some simple procedures discussed at length in some older posts, alternating heat, cold, and bumping with a rubber mallet.

I was looking for a thermometer for a second one I have on the shelf. Thanks

dykker5502 wrote: ↑

Fri Nov 05, 2021 5:23 pm

Get rid of that waterpump! You obviously don't need it! 15 million T's where made without them.

Michael, Could you be a bit more specific please?

MichaelPawelek wrote: ↑

Fri Nov 05, 2021 1:47 pm

Has anyone added a coil of copper wire or a spring to the bottom of their Moto meter so it actually extends into the radiator water and registers properly?
The 24 Coupe I’m working on now has a flat tube radiator and cools so well that the water level never comes up high enough to touch the Moto meter and I just don’t get a decent reading. The meter works fine dipping the lower part into hot water on the stove so I know the problem does not lie there. Thanks

Have you considered that the Moto Meter may have been designed and calibrated to be a steam gauge not a water temperature gauge? Note the position of the sensor bulb in the radiator neck. The patent text 1090776 https://patents.google.com/patent/US1090776
the protuberance 24 and-within the air s ace or' pocket 36 formed in tl ie'inlet 20- and -the upper part of the 'radiatorabove the level '0 the waterwi thin-the radiator/I, the bulb. being protected against fracture or breakage bg athimble orcap 37 formed of metal or t e tuberance 24 and providedwith a plurality of apertures or holes 38 as-shown in Fig.. 3.. It will beapparent-from"the-'foregoin that the bulb of the thermometer-'31, extend ing'into' the airspace 36 will cause the inso dicating fluid, which may bealcohol, glycerin,'or any other suitable medium which will retain. its homogeneity or solidity -regardless of the vibration of the system of which it is apart, to respond to changes-in the'temperature of the atmosphere within the air space 36, whichis inpr'bximity to the point-{of inflow 19st the heated water com-- ing fronrthecylinder jackets -The; plate 32 to which th'e'thermometer 40' is secured is ositioned to. the rear thereof, its front face eing provided with the


By John Berch on Wednesday, December 21, 2011 - 04:41 pm:
The original Moto Meters are a steam gauge and are calibrated to operate that way.
I don't know anything about the new reproduction Moto Meters, so I can't comment on them. I don't know what they use in the thermometer on the repops but the originals were Glycerin and alcohol.
The reason for the stem not being submerged in coolant was intentional. I would think any modifications to imitate a submerged condition would alter the reading intended, at least in the lower reading and might insulate it, slowing reaction time of the meter. Boyce's theory was that the air in the radiator tank above the coolant could be as much as 30 to 50 degrees cooler than the coolant itself. If boiling occurs this changes very quickly as the steam from an overheat condition sends the red column into the danger zone very quickly. The meter is calibrated to show a low reading for operating temp and to show a spike in the sight glass when boiling. Operating temperature is very close to boiling so on a submerged thermometer your gauge would register very high all the time with very little movement as it moved in to the boiling range.
--
--
There is no temperature value in degrees just a relative indication of the cooling system functioning properly.

MichaelPawelek wrote: ↑

Fri Nov 05, 2021 2:59 pm

This morning I ran the T for 10-12 miles and even idled it with the spark retarded trying to get it to over heat a bit and 160 degrees was as hot as I could get it using a meat thermometer in the neck of the radiator. Outside temperature was 65 F.

This ‘24 T already had a water pump installed so I am installing a 180 degree thermostat tomorrow and already have a infrared thermometer on order.

Pitch the pump, you obviously don't need it. You do need the thermostat for two reasons" 1. the operating temperature of the engine needs to be about 180 degrees Fahrenheit for proper combustion to occur. 2: the Model T cooling system uses thermosiphoning to flow the coolant through the system and as such requires a temperature differential from the coolant inlet at the top of the radiator to the outlet at the bottom. <- you got that covered!

Some people added water pumps in order to use kerosene as a non-freezing winter coolant in cold regions. That's not something I'd want to try, but if I lived in an area with hard winters, I might consider adding a water pump and using ATF as a coolant in a car in light duty service during winter months.

MichaelPawelek wrote: ↑

Fri Nov 05, 2021 7:00 pm

dykker5502 wrote: ↑

Fri Nov 05, 2021 5:23 pm

Get rid of that waterpump! You obviously don't need it! 15 million T's where made without them.

Michael, Could you be a bit more specific please?

You wrote somewhere that you have a waterpump on your car.

Model T's did not have waterpumps from factory (except for the first 2500 back in 1908).

Somebody have dome symptom treating by adding a accessory waterpump to the car as it apparently overheated.
Eventually someone (else?) fixed the rootcause and flushed the system and exchanged the radiator or just the core.
The termosyphon colling system in a model T are kind of selfregulating so as much heat are generated the faster the water circulates and keep it from boiling.
Now that is destroyed with the waterpump, that force the water around faster than needed >>>> Your car is to cold.
Remove the watrerpump and all may be just good.