Water inlet for temp gauge

[RTC1930]

I know the water outlet neck is the best place for the temp gauge but does any one run one of these threaded water inlets to hook up the temp gauge? I feel routing the tube from this would look a lot cleaner then routing it from the front. I just need to account for the delta between upper and lower temps while reading the gauge. Does anyone else do this? Am I missing something?

Thanks,
Bob NJ

[Rainmaker Ron]

Originally Posted by RTC1930

I know the water outlet neck is the best place for the temp gauge but does any one run one of these threaded water inlets to hook up the temp gauge? I feel routing the tube from this would look a lot cleaner then routing it from the front. I just need to account for the delta between upper and lower temps while reading the gauge. Does anyone else do this? Am I missing something?

Thanks,
Bob NJ

I put mine in the lower water tube by brazing in a fitting. No way do I want to see that ugly thermocoupler "strung" around my engine compartment! Delta is about 20 degrees and you will soon adjust to what is "normal" for your car.
Rainmaker Ron

[ctlikon0712]

I run mine in the lower tube also, no problems!

[bdentremont]

Originally Posted by RTC1930

I know the water outlet neck is the best place for the temp gauge but does any one run one of these threaded water inlets to hook up the temp gauge? I feel routing the tube from this would look a lot cleaner then routing it from the front. I just need to account for the delta between upper and lower temps while reading the gauge. Does anyone else do this? Am I missing something?

Thanks,
Bob NJ

Under ordinary conditions of radiator-limited cooling, I'm sure ctlikon0712 is right. However, if you run a thermostat in the top tube, what you might miss is feedback on it's function. If the thermostat stuck closed, the engine and the water leaving it would get unusually hot, so a top tube thermometer would indicate a problem. However, with the radiator functioning perfectly well, your water return temperature would be normal or even a little cool due to less total heat being put in the radiator.

[pdora]

I have senders installed in both the outlet and inlet tubes. They are wired through a SPDT switch into a single temperature meter. The switch is located next to the meter, providing a quick comparison of the two readings. I set this up to keep an eye on engine temperature (indirect) and radiator performance

The difference between the two readings (delta) varies widely depending on ambient temperature, speed, load, coolant level and probably some unknowns as well.

The whole point of a temperature gauge is to provide a proxy for conditions inside the engine, so as to avoid damage and enhance efficiency. The outlet is the closest practical sampling location.

BACKGROUND:

I really like to know what's going on inside my engine. Currently I have the stock ammeter, a digital voltmeter and a vacuum gauge. Next will come a tachometer, and perhaps some kind of tailpipe emissions analysis.

The ultimate goal is to eliminate most of the readouts, add a bevy of sensors and capture all data in digital form for real-time display and offline analysis.

Adding a computer and analog-to-digital converters to an automobile requires a very clean and stable power source. Therefore, I have converted (careful not to say 'upgraded' on the Ford Barn) to 12 volt and am working on RF noise suppression.

I will be happy to chronicle this project on the Ford Barn as it progresses over the years.

[Tom Wesenberg]

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Peter, I like your analytical thinking, but talk about turning a basic driving experience into a research lab..............WHOA!!!!!!!!

[kenparker]

pdora likes gadgets and technology. koodos kid, me too. I had not thought of the one gauge and a SPDT switch, Thanks. ken

[1931 flamingo]

Some people (pdora, I enjoy your posts very much) have WAY too much time on their hands!!!!! JMO
Paul in CT

[RTC1930]

Thanks for your replies! I should have mentioned I have a motometer on my cap so hopefully that should indicate any catastrophic failure in the cooling system. I just want a little more data (not as much as Peter) on what the cooling system is doing for piece of mind.

Peter, I definitely can appreciate your efforts as I'm resisting adding every type of gauge to be fully assured the engine is operating at peak performance. The car is bone stock though with no extra holes in the firewall, hence the hesitation to even add a temp gauge.

Thanks,
Bob NJ

[Gus]

Pdora, I would be interested to hear how your data capture efforts are going.

I am restoring at the moment and am considering how best to capture basic engine data without 'spoiling' the original look and parts. I might attempt a digital solution (Arduino microprocessor) like you, but would like to keep the 6V. Any ideas how to get a stable power supply?

I want to capture RPM, water temp, battery voltage, and perhaps speed.

Curiosity gets expensive and complicated!

Gus

[BILL WILLIAMSON]

Chief drilled & tapped 1/4" NPT in the L/R side of the head. He thought that was the best place. Mapped out a location when head was off, haven't drilled yet. Has anyone used this location? Bill W.

[Rich in Tucson]

For a stable power supply, why not use a separate battery for the instrumentation? 6, 12, 24, 48 V whatever suits your equipment.

[Fred K-OR]

I have a lower water outlet that has a hole drilled in it and it had some kind of electrical temp gage in it. This was on the engine I just purchased to put in my coupe. I don't think I will use it because the hole drilled in it was about a 3/4 in hole and it was threaded. My concern is that it will leak water plus the fact I was not sure what type of gage to hook to the unit that was in the outlet. So if anyone wants this thing, send me a PM and I can send a picture of it.

BTW I have a Motometer on my huckster. We were over in Boise this week and drove about 50 miles in 93 degree weather and it did show some temp rise. So it would seem like if you only want to know if you engine is getting a bit hot, this thing should give you a pretty good idea. After all old Henry said something like " You don't need all those things, you know when it is hot, it boils over"

[mass A man]

Henry would be proud of his little old truck of mine. NO extras, As Henry built it, with '35 wire wheels that were on it since the'40's. An 81 yr. old radiator too, with temps in the mid to high 90's here. Having a ball driving it all over. No water loss, no boiling over. No vapor lock either. I'd better not jinx myself now. Am I courting disaster??

[steve s]

Originally Posted by bdentremont

Under ordinary conditions of radiator-limited cooling, I'm sure ctlikon0712 is right. However, if you run a thermostat in the top tube, what you might miss is feedback on it's function. If the thermostat stuck closed, the engine and the water leaving it would get unusually hot, so a top tube thermometer would indicate a problem. However, with the radiator functioning perfectly well, your water return temperature would be normal or even a little cool due to less total heat being put in the radiator.

I think the above is a good analysis.

I remember puzzling over this when Charlie Yapp first came out with the modified inlet--he's a sharp fellow, but I still don't get it--I think he had more in mind than just a fun source of comparison data for the real, i.e, upper, gauge. I wonder if someone can describe for us a scenario problem for which the lower-mounted temperature sensor will be any help at all? It seems to me that that sensor will be the last to know.

Steve