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Old 06-25-2013, 05:04 PM   #31
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Originally Posted by JimsJeep View Post
I had an argument with a mechanical engineer in the old World Trade Center regarding the reason they specified pipe insulation on all sprinkler systems within 10' of the window wall. He said is was to keep the water from freezing. (water is static in pipe) I told him ambient temperature is ambient temperature and that insulation will not warm the pipe. So what possible good could that do. I lost by virtue of seniority.

Based on that same note, put 3 similar jeeps side by side in the desert, 1 with a OEM stat one with a 165 and one with no stat. Let them idle at the same RPM for one hour. Will the jeeps record different operating temperatures, not possible.
It should be possible, given the right circumstances. If the cooling system is capable of lowering the coolant temperature below the ideal operating temperature, the thermostat choice will matter, so long as it's not below the cooling capacity of the system.

My coolant temperature never raises above 210, even when it's 110+ outside. Idling, going up steep hills at WOT, nothing causes any significant changes in the operating temperature. Would it be safe to assume then, that the cooling system is capable of cooling lower than the ideal operating temperature? If it weren't, it seems to me it would have problems overheating.

Just putting this out there for discussion, I run a 195 degree thermostat like it's supposed to have.

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Old 06-25-2013, 05:35 PM   #32
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I had an argument with a mechanical engineer in the old World Trade Center regarding the reason they specified pipe insulation on all sprinkler systems within 10' of the window wall. He said is was to keep the water from freezing. (water is static in pipe) I told him ambient temperature is ambient temperature and that insulation will not warm the pipe. So what possible good could that do. I lost by virtue of seniority.

Based on that same note, put 3 similar jeeps side by side in the desert, 1 with a OEM stat one with a 165 and one with no stat. Let them idle at the same RPM for one hour. Will the jeeps record different operating temperatures, not possible.
You lost because the insulation reduces the rate of heat escaping the insulation protected water when the window is open.

When the window is closed, the insulated water reached equilibrium with the ambient temperature, about 70 degF. If a window were opened on a cold winter day, the ambient will drop and the water will cool until it reaches that cold temperature. It will cool slower with insulation. And slower is good.

TJs with the same type thermostat but different temperature ratings will all be full open in a very hot climate. So flow through the radiator will be the same. But removing the thermostat completely will improve flow and provide more cooling.

In fact, a better way to regulate engine temperature is to keep the water at full flow and regulate the air across the radiator. Not too easy to do. It takes a radiator shutter and a variable speed fan. This arrangement also reduces uneven cylinder wear.

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Old 06-25-2013, 05:44 PM   #33
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You lost because the insulation reduces the rate of heat escaping the insulation protected water when the window is open.
You missed the point he made on the fact the water is in a sprinkler system so it doesn't move unless there is a fire & the sprinklers turn on. In that use, the water inside the pipes soon becomes & then remains at the ambient temperature of the air in the surrounding area. Just like non-moving water inside insulated pipes will freeze in an unheated/unoccupied house when the ambient air temp is below freezing. Putting a jacket on a loaf of bread in the kitchen won't warm it up.
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Old 06-25-2013, 05:53 PM   #34
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You lost because the insulation reduces the rate of heat escaping the insulation protected water when the window is open.

When the window is closed, the insulated water reached equilibrium with the ambient temperature, about 70 degF. If a window were opened on a cold winter day, the ambient will drop and the water will cool until it reaches that cold temperature. It will cool slower with insulation. And slower is good.

TJs with the same type thermostat but different temperature ratings will all be full open in a very hot climate. So flow through the radiator will be the same. But removing the thermostat completely will improve flow and provide more cooling.

In fact, a better way to regulate engine temperature is to keep the water at full flow and regulate the air across the radiator. Not too easy to do. It takes a radiator shutter and a variable speed fan. This arrangement also reduces uneven cylinder wear.
Windows did not open in the WTC
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Old 06-25-2013, 09:13 PM   #35
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You missed the point he made on the fact the water is in a sprinkler system so it doesn't move unless there is a fire & the sprinklers turn on. In that use, the water inside the pipes soon becomes & then remains at the ambient temperature of the air in the surrounding area. Just like non-moving water inside insulated pipes will freeze in an unheated/unoccupied house when the ambient air temp is below freezing. Putting a jacket on a loaf of bread in the kitchen won't warm it up.
The point is that the still water in an insulated pipe will retain its heat for a longer period than water in an uninsulated pipe. The hope is that some will close the window, repair the window or fix the building's heating system before the pipe freezes. And this is especially significant since the amount of lost energy must not only exceed the apparent heat loss, but the latent (energy of conversion) heat loss before the pipe freezes.
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Old 06-25-2013, 09:14 PM   #36
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Windows did not open in the WTC
But if heating is lost in the building, or a window comes out, the insulation may buy time to fix the problem before freezing the pipe.
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Old 06-25-2013, 10:11 PM   #37
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Jerry,

Thank you for your direct response. Can you tell me what I can do to remove the bubble of air near the temp sending unit? What symptoms would there be??

It's funny because about a week ago, it was running hotter than it is today. A week ago, it was running a 225 now 215. So what gives????

I'm also of the firm belief that lowering the thermostat degree will merely permit coolant to be released into the radiator sooner/at a lower temp. The effect that that has is it allows the engine to begin cooling sooner. But, will not change the dimensions, capacity, coolant type or flow. Therefore, if the system is designed to run at approx. 200, changing the thermostat to a lower degree, will only cause the system to begin cooling sooner. It will not permit the system to cool more effectively.

Removing the thermostat can have the effect of allowing the engine to run cooler. The reason is because the thermostat when fully opened, (and they are usually the same, 160, 180, 195) only opens approx 1/4 inch around the entire circumference of the t-stat. Thereby allowing only a certain amount of coolant to pass into the t-stat housing and back into the radiator to be cooled.

Removing it all together permits greater capacity of coolant to leave the engine hot and be supplied to the radiator for cooling. This could have the effect of allowing more coolant into the radiator effectively cooling more surface area of coolant, thereby dropping the coolant temperature.

Techincally, the amount the t-stat opens is direct relationship to the water pumps volume capacity and it opens just enough to provide for the coolant that is in the radiator to move through it at a rate which allows the coolant to drop in temperature. It drops niether too much nor too little.

Of course this is all effected by the # of fan blades, the rate at which the fan pulls air through the radiator, the ambient outside temperature, the mixture ratio and type of coolant and the volume at which the water pump moves the coolant. There are other factors, such as size and type of radiator, types of hoses ect...

Now if I could just figure out why my Jeeps running hot. Again, if it's an air bubble, what sings would there be. Would the gauge fluxuate around turns? It's doing that slightly. Another things I've noticed is that it runs at 215-220 with the rad cap on, but with it off it holds a steady 190. Any thoughs there???
I'll pop a hole in your theory. When my last thermostat (195) failed open the engine would barely get up to 160*. This is not measured by the inaccurate gauge but my scangauge. Also, with a 195* thermostat my normal operating temp is 198*.
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Old 01-20-2015, 12:33 PM   #38
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T-stats or Thermostats raise or lower the temp

I am a engineer and a thermostat controls the flow according to temp , IE it starts to crack open around the temp it is made for and will continue to open more and more as the temp rises, but as the engine speed, altitude ( lean /rich ), load, etc will govern how hard the engine is working ( IE: low gear high RPM when climbing versus high gear low RPM ) the thermostat will start to close or open according to the temp of the coolant passing over the T-stat in which it is trying to maintain a constant temp. again it T-stat is removed it does not always mean it is going to run cooler due to the fact if the coolant is running to fast thru the radiator core it does not have time to cool down and therefor is going to keep getting hotter until it reaches a point of boiling over this is based on a single core radiator and that more cores dont always help to remedy the problem unless more air can be pulled thru at slower speeds ( electric aux fans can sometimes increase air flow but coolant still needs to slow down enough to exchange heat also...I can throw all kinds of scenarios and combos
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Old 01-20-2015, 01:01 PM   #39
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to chaange or not to change that is thy question

I am a engineer and a thermostat controls the flow according to temp , IE it starts to crack open around the temp it is made for and will continue to open more and more as the temp rises, but as the engine speed, altitude ( lean /rich ), load, etc will govern how hard the engine is working ( IE: low gear high RPM when climbing versus high gear low RPM ) the thermostat will start to close or open according to the temp of the coolant passing over the T-stat in which it is trying to maintain a constant temp. again it T-stat is removed it does not always mean it is going to run cooler due to the fact if the coolant is running to fast thru the radiator core it does not have time to cool down and therefor is going to keep getting hotter until it reaches a point of boiling over this is based on a single core radiator and that more cores dont always help to remedy the problem unless more air can be pulled thru at slower speeds ( electric aux fans can sometimes increase air flow but coolant still needs to slow down enough to exchange heat also...I can throw all kinds of scenarios and combos
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Old 01-20-2015, 01:28 PM   #40
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sorry somehow it got posted twice
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Old 01-20-2015, 01:44 PM   #41
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OP....
Has the system been flushed well? Is the coolant the proper type & 50% mix?

If your temp is fluctuating and you are sure your thermostat is good (195F, NON-fail safe factory or Stant) then all that is left is water pump, fan clutch, or a clogged up system.
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Old 01-20-2015, 01:54 PM   #42
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Also a heads up in my early days of shade tree mechanic wisdom I figured I would open up the smaller holes on my new head gaskets for better cooling ....NOT...... it is designed to cool some areas different than other ares by opening them up one side of my cylinder go to much coolant and the other side didn't get enough and lets just say that 20 dollars head gasket fiasco cost me a new rebuilt HiPo engine...heck of a learning curve you might say
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Old 02-13-2015, 11:39 PM   #43
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Y'all are a bunch of whiners. He said she said b.s.
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Old 02-14-2015, 08:12 AM   #44
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Everyone knows that insulated anything will not lose it's warmth as fast as uninsulated anything.
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Old 02-14-2015, 07:42 PM   #45
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OP....
Has the system been flushed well?
Is the coolant the proper type & 50% mix?

If your temp is fluctuating and you are sure your thermostat is good (195F, NON-fail safe factory or Stant) then all that is left is water pump, fan clutch, or a clogged up system.

Lol. Hopefully several times by now since it's been almost 5 years since this thread started. It keeps getting resurrected.

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