Water temperature

[old skool]

I am running a 5.5 to 1 HCH on my stock Model A Ford (told they run cooler). What is the ideal water temperature I am looking for? I have seen (on line) everything from 140 to 180 degrees F. Worked really hard on this engine and I want it to last a long time.

While I have you, what should the oil pressure. I know its low.

Thanks,
Marty

[WestCoast]

for optimum fuel mileage and power try for between 160 and 180, 180 is the preferred temp, at that temp the fuel burns almost completely, any moisture picked up will be evaporated from the crank case leaving the oil and all of the engine cleaner, no carbon or sludge build up

[Chuck Sea/Tac]

Exactly, the hotter is better

[old skool]

Thanks for the tip. My car is running a little cool. I will fix that problem.

[Tom Wesenberg]

A 180 thermostat and antifreeze will be good for the engine.

[Mike V. Florida]

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Originally Posted by old skool

I am running a 5.5 to 1 HCH on my stock Model A Ford (told they run cooler). What is the ideal water temperature I am looking for? I have seen (on line) everything from 140 to 180 degrees F. Worked really hard on this engine and I want it to last a long time.

While I have you, what should the oil pressure. I know its low.

Thanks,
Marty

If you have stock oiling, then yes near zero is correct when warmed up.

[Mike V. Florida]

Where did the Water temperature number come from?

Were they documented by Ford? Did someone do testing? Are the numbers the same for all engines?

I am not doubting the 180 degree temp, I would just like to fill out my education on where things come from.

[Y-Blockhead]

Originally Posted by Tom Wesenberg

A 180 thermostat and antifreeze will be good for the engine.

Waayyy back last October a few months after I got my Town Sedan I asked a question about which thermostat to get (see link below) because the car seemed to be running too cold and the general consensus was to go with the 160°F.

Now I wish I had gone with my gut feeling back then and gone with the 180°F thermostat because even tho it now warms up faster it still runs around 160-165°F and I feel I would run better if warmer.

https://www.fordbarn.com/forum/showthread.php?t=152047

[CarlG]

I have a 160° thermostat in mine as well. It rarely will get into anything above 165°. If I wanted it to run warmer, a 180° thermostat would be an easy fix. My only problem with that is that with a 180° in there it's going to run a little hotter than that anyway (+5°or 10°, and that gets me closer to the max line I don't want to cross.

Right now, I'm happy with 160° to 165°.

[Y-Blockhead]

Well my way of looking at it is if your cooling system is running higher than than say 190°F it won't matter if you have a 160° or 180° thermostat because at that temperature both thermostats will be WFO.

I just would like it controlled to 180-185°F which means since it runs at 165° now the 180° thermostat will run partially closed to maintain 180°F and will open up more if the temperature rises.

[Jim/GA]

Originally Posted by CarlG

I have a 160° thermostat in mine as well. It rarely will get into anything above 165°. If I wanted it to run warmer, a 180° thermostat would be an easy fix. My only problem with that is that with a 180° in there it's going to run a little hotter than that anyway (+5°or 10°, and that gets me closer to the max line I don't want to cross.

Right now, I'm happy with 160° to 165°.

Carl-
If I lived in Alaska, I'd run a 180 degree thermostat.

Down here in Texas my engine will run at 180 with no thermostat.

[Brendan]

before I put a 165 stat in my car, it would not move the gauge, that is to cold

[Mitch//pa]

agree Carl a 160 stat is fine and your better off staying away from the 190 range on these old turkeys.

[modelAtony]

Originally Posted by old skool

I am running a 5.5 to 1 HCH on my stock Model A Ford (told they run cooler). What is the ideal water temperature I am looking for? I have seen (on line) everything from 140 to 180 degrees F. Worked really hard on this engine and I want it to last a long time.

While I have you, what should the oil pressure. I know its low.

Thanks,
Marty

Remember to watch the outside temp. 180 is fine now if your car is running this temp. Summer time temps around 90-97 your car will be running 190 or above this is not good. the reason some don't run thermo. during summer months. have fun modelAtony tony white Lafayette, LA

[tim54889]

Sooo, how does a 180 thermostat cause the engine to run over 190???

[Y-Blockhead]

Originally Posted by tim54889

Sooo, how does a 180 thermostat cause the engine to run over 190???

It can't...

[Mike V. Florida]

Originally Posted by tim54889

Sooo, how does a 180 thermostat cause the engine to run over 190???

Originally Posted by Y-Blockhead

It can't...

I think what he is trying to say is that the thermostat may not open exactly at 180. If it is off by 10% the temp can rise up to 198 before it opens. The same 10% for a 160 means 176 before it opens.

Just my interpretation of what was written.

[RonC]

The purpose of the thermostat is to keep an engine at its ideal operating temperature of approximately 160 to 195 degrees. Cylinder wear is reduced when an engine operates between those temperatures. The Model A cooling system was not designed for a thermostat. Adding a thermostat is a design change. It changes the cooling fluid flow when closed and when open as the orifice is smaller than the hose. A thermostat will allow and engine to get from zero to 160 faster than without one so yes less wear when cold. The question is what operating temperature will your engine be at with versus without a thermostat? If it does cause your engine to run above 195 more often than without then wouldn't you be causing more cylinder wear?

[Chris in CT]

Originally Posted by Mike V. Florida

Where did the Water temperature number come from?

Were they documented by Ford? Did someone do testing? Are the numbers the same for all engines?

I am not doubting the 180 degree temp, I would just like to fill out my education on where things come from.

Hi Mike,

I think the 180 figure comes from the fact that steam vapors begin to occur at that temperature. Given a 180 measured temperature, you can probably rely on the fact that hot spots in the engine will run in excess of that temperature. Ideally, no part of the engine would run in excess of 180, which probably means a lower net temperature setting. These rules would change, of course, in a coolant-pressurized engine...

Chris

[BN]

I fear that we may be shortening the life of our Model A engines by installing a thermostat within the circulating coolant system, especially when driving them in warmer weather. Here are the reasons why:

• The Model A does not have a bypass system as on more modern engines.
  
  • A bypass system bypasses the radiator but keeps coolant circulating through the block when the thermostat is closed.
• The Model A coolant flow depends primarily on the “Thermal - Siphon” effect, supplemented by a water pump at higher RPM.
  
  • The “effect” of the “Thermal – Siphon” effect is greatly reduced by any restrictions in the flow path, such a a thermostat.
• When the thermostat is open, it still presents a large restriction reducing coolant flow adjacent to the cylinder walls and head.
• Therefore, the bubbles attached to the water jacket due to boiling cannot be as readily carried away, resulting in localized overheating at the cylinder walls and valve seats.
  
  • It is desired to keep the oil film on the inside of cylinder walls under about 375 Deg F. Otherwise the oil film will begin to vaporize, resulting in increased upper cylinder wall wear. Also the valve seats will run hotter, resulting in shorter seat and valve life.
• Finally, the “Thermal – Siphon” effect already acts as a thermostat by increasing coolant flow as the coolant increases in temperature.

I would recommend a study of the seminar put out by Rocky Mountain A's entitled “What coolant to use”. The concept of “Nucleate Boiling” is discussed here. This phase change (in this case, water to steam) occurs at the jacket surfaces in any liquid cooled engine once a certain heat load is reached. This phase change cooling is similar to an air conditioning system in which the liquid freon flashes to gas in the evaporator, resulting in the absorption of heat). The bubbles which form on the jacket walls are carried away by the coolant flow where they later condense. New bubbles form, and the cycle continues.


Here is a link to the above seminar. I have read it, and (as a mechanical engineer) have found it basically sound.


http://rmaford.org/wp-content/blogs....uids_v2007.pdf