Coolant Boiling Question
08-22-2007, 11:56 PM
#101
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<< working on a Hydrogen solution. Based on what I have learned here my primary concern is finding a substance with a High heat capacity. Hydrogen has over 3 times the heat capacity of water, so it should make for an even better cooling solution. Taking research donations....
08-23-2007, 12:02 AM
#102
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The funny thing is that the heat transfer of water vs glycol was never a question at all. The OP stated that as fact.
The problem is that there is no way to directly measure "bubbles in the engine"... The only evidence we have is what is observable - the heat transfer efficiency, and the extra wear induced by corrosion. One of those is fairly easy to determine, but the second is a long-term effect so none of us have the resources to do that kind of testing. The only way we can come to a conclusion is via empirical evidence....
The problem is that there is no way to directly measure "bubbles in the engine"... The only evidence we have is what is observable - the heat transfer efficiency, and the extra wear induced by corrosion. One of those is fairly easy to determine, but the second is a long-term effect so none of us have the resources to do that kind of testing. The only way we can come to a conclusion is via empirical evidence....
08-23-2007, 02:00 AM
#106
OK.
Dangerous language - especially since you have not defined what you mean by "coolant". I think it is safe to say that many people do NOT know this, so they continue to be swayed by anti-freeze vendors that want to assure sales in regions unaffected by freezing temperatures, among other reasons.
The thermostat opens at 176°F. It is completely open at 220°F.
BTW - Lower than what?
Sort of. The motor will not just spontaneously destroy itself were the temperature to go above the boiling point for the coolant under pressure. There is a long stretch where water will continue to absorb heat after the static temperature is at its conditional boiling point. There are times where a motor's oil temp might be near 280°F - meaning the coolant heat rejection point has been surpassed - and it will keep on going just fine before it thermally overloads. Just ask some of the folks that have tracked their '8.
I think you are trying to use experience in the kitchen to understand what is going on inside the motor and it doesn't follow. Bubbles form?
Here is a fun experiment (and a good example of why you shouldn't use tap water in the cooling system):
Take a Pyrex measuring cup and scrub it with white vinegar and rinse it thoroughly with distilled water.
Fill it half-way with distilled water and put it in the microwave along with another cup full of regular tap water.
Turn on the microwave in a run (continuous high power) mode and leave it running until something happens.
If you want a nice surprise, after something happens, put some flour or sugar into the cup where nothing happened. Keep your face out of the way.
Originally Posted by LionZoo
Okay, so as we all know water is more effective at removing heat from the engine than coolant or antifreeze.
Originally Posted by LionZoo
However, water also has a lower boiling point of 212 degrees and our thermostat opens in that temperature region.
BTW - Lower than what?
Originally Posted by LionZoo
Since our cooling system is pressurized, I'm assuming the pressure is enough to keep the water liquid to a high enough temperature that if water does boil, the engine would be toast anyway.
Originally Posted by LionZoo
(Chemistry 101) Bubbles begin to form much earlier than the real boiling point though, so I'm wondering if there's an increased likelihood of small bubbles forming that will reduce cooling system efficiency when using pure water (plus an anti-corrosion agent) versus an actual coolant mix.
Here is a fun experiment (and a good example of why you shouldn't use tap water in the cooling system):
Take a Pyrex measuring cup and scrub it with white vinegar and rinse it thoroughly with distilled water.
Fill it half-way with distilled water and put it in the microwave along with another cup full of regular tap water.
Turn on the microwave in a run (continuous high power) mode and leave it running until something happens.
If you want a nice surprise, after something happens, put some flour or sugar into the cup where nothing happened. Keep your face out of the way.
08-23-2007, 02:24 AM
#107
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Alright, read it again, here's my response.
I tried inserting "or antifreeze" to show that my use of coolant was in prefer to EG mix rather than something else. I THOUGHT that it was common knowledge for people that I expected to respond to this thread, but obviously that wasn't the case.
Water has a lower boiling point compared to a typical antifreeze mix. Once again, bad prose. I knew the thermostat was fully open at 220, but I was unaware that it started opening at 176.
I was never under the impression that the motor would just explode at a certain temperature, but rather I was just using Racing Beat's 220 (or is that 230? I don't have the catalog with me right now) rule of thumb as the maximum the coolant should be allowed to reach and beyond that point the rotary's life would be significantly abbreviated. In otherwords, beyond that point it would just be fully bad news and so it would be best to avoid that region. Though I understand your point about the engine continuing to function and now realize that my assumption is faulty, I'm also not sure if quoting oil temperature is a valid example. This is because oil is shared with other moving components of the engine and their friction will be contributing more heat to the engine than just the waterjackets that the coolant flows in. Also, oil has different heat transfer properties compared to coolant.
My term of bubbles forming was really poor. What I was trying to say was that there would be localized boiling way before the coolant itself completely boils over. Since glycol has a higher boiling temperature, my question was if EG mix would be more resistant to localized boiling than pure water.
I tried inserting "or antifreeze" to show that my use of coolant was in prefer to EG mix rather than something else. I THOUGHT that it was common knowledge for people that I expected to respond to this thread, but obviously that wasn't the case.
Water has a lower boiling point compared to a typical antifreeze mix. Once again, bad prose. I knew the thermostat was fully open at 220, but I was unaware that it started opening at 176.
I was never under the impression that the motor would just explode at a certain temperature, but rather I was just using Racing Beat's 220 (or is that 230? I don't have the catalog with me right now) rule of thumb as the maximum the coolant should be allowed to reach and beyond that point the rotary's life would be significantly abbreviated. In otherwords, beyond that point it would just be fully bad news and so it would be best to avoid that region. Though I understand your point about the engine continuing to function and now realize that my assumption is faulty, I'm also not sure if quoting oil temperature is a valid example. This is because oil is shared with other moving components of the engine and their friction will be contributing more heat to the engine than just the waterjackets that the coolant flows in. Also, oil has different heat transfer properties compared to coolant.
My term of bubbles forming was really poor. What I was trying to say was that there would be localized boiling way before the coolant itself completely boils over. Since glycol has a higher boiling temperature, my question was if EG mix would be more resistant to localized boiling than pure water.
08-23-2007, 02:39 AM
#108
There is oil in far more places in the engine than coolant, so its job is to convey most of the heat to the water jacket from those places.
Something like 75% of all the energy created by combustion is wasted as heat, half of which goes into the coolant.
However, something like 20% of the energy that is not lost to heat is actually used to overcome friction in the motor. What do you think that friction turns into?
In all, the original post may not have said what you "meant", but you would be better served if you actually did say what you meant.
08-23-2007, 02:54 AM
#109
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Heat is heat. The coolant doesn't know where it is coming from.
There is oil in far more places in the engine than coolant, so its job is to convey most of the heat to the water jacket from those places.
Something like 75% of all the energy created by combustion is wasted as heat, half of which goes into the coolant.
However, something like 20% of the energy that is not lost to heat is actually used to overcome friction in the motor. What do you think that friction turns into?
There is oil in far more places in the engine than coolant, so its job is to convey most of the heat to the water jacket from those places.
Something like 75% of all the energy created by combustion is wasted as heat, half of which goes into the coolant.
However, something like 20% of the energy that is not lost to heat is actually used to overcome friction in the motor. What do you think that friction turns into?
I agree somewhat with the 75% number, but I think overcoming friction accounts for much less than 20% of the energy of combustion. If I recall correctly, the number is around 10%, but it's been awhile. Nonetheless, that is a small detail and of course what you were trying to get at is that friction turns into heat that must be evacuated by the oil. We're in agreement here.
08-23-2007, 07:19 AM
#111
Sure it's marketing material for a product, but the explanation of how it works isn't opinion. It explains a lot of things, which half the people posting here don't seem to understand. Funny since those very same people reject any explanations put forth.
I can't recall any other discussion on this forum that has gone on for so long, with so many posts, that basically reiterates the same thing over and over. There are only so many ways to say that water is 2 to 3 times more effective at heat transfer than glycol. And even that is apparently rejected as false marketing propaganda.
08-23-2007, 08:12 AM
#112
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OK fine mysql...lets play your game.
According to your numbers 50/50 glycol mix can be measured at 228F after circulating in an engine for 3 hours at 7000 RPM. Do you dispute that statement?
According to your numbers 100% distilled water under the same conditions comes out at 220F. Do you dispute that statement?
If you answered no to both of the above 2 lines, please explain to me where distilled water is 2 to 3 times more effective at heat transfer than the glycol based solution. Or are you saying that water is 2 to 3 times more effective at heat transfer than 100% glycol, which nobody would run? And please explain how any of this has anything to do with the question that was asked.
Also, is it worth the lower boiling point for only 8F cooler coolant? I think not...I will take the year round safety and protection of an EG based coolant.
CnnmnSchnpps thinks that we are trolls for questioning what you have said. Fine, so be it, think what you want. I know that I actually own an 8 and am trying to learn everything I can about it. Now, if asking questions and discussing things like this is wrong, maybe I joined the wrong forums. However, the way it appears more and more people are starting to see where myself, and my coworkers, are coming from. The reason why this thread got so long in the first place is you answered an honest question about boiling coolant with a sales pitch for a product that doesn't help. Even MM and staticlag have backed up what we have said and stated that you should at least have 30% EG in your system. Which goes back to what ProChargerGT, grey1, ms6ftw and myself have said all along, running a 100% WW solution doesn't make sense under normal street driving conditions.
According to your numbers 50/50 glycol mix can be measured at 228F after circulating in an engine for 3 hours at 7000 RPM. Do you dispute that statement?
According to your numbers 100% distilled water under the same conditions comes out at 220F. Do you dispute that statement?
If you answered no to both of the above 2 lines, please explain to me where distilled water is 2 to 3 times more effective at heat transfer than the glycol based solution. Or are you saying that water is 2 to 3 times more effective at heat transfer than 100% glycol, which nobody would run? And please explain how any of this has anything to do with the question that was asked.
Also, is it worth the lower boiling point for only 8F cooler coolant? I think not...I will take the year round safety and protection of an EG based coolant.
CnnmnSchnpps thinks that we are trolls for questioning what you have said. Fine, so be it, think what you want. I know that I actually own an 8 and am trying to learn everything I can about it. Now, if asking questions and discussing things like this is wrong, maybe I joined the wrong forums. However, the way it appears more and more people are starting to see where myself, and my coworkers, are coming from. The reason why this thread got so long in the first place is you answered an honest question about boiling coolant with a sales pitch for a product that doesn't help. Even MM and staticlag have backed up what we have said and stated that you should at least have 30% EG in your system. Which goes back to what ProChargerGT, grey1, ms6ftw and myself have said all along, running a 100% WW solution doesn't make sense under normal street driving conditions.
Last edited by DeViLbOi; 08-23-2007 at 08:15 AM.
08-23-2007, 12:36 PM
#113
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Even MM and staticlag have backed up what we have said and stated that you should at least have 30% EG in your system. Which goes back to what ProChargerGT, grey1, ms6ftw and myself have said all along, running a 100% WW solution doesn't make sense under normal street driving conditions.
08-23-2007, 12:49 PM
#114
This is why we have oil coolers; if oil temperature was always that of coolant temperature than there would be no need for oil coolers and instead we could just increase radiator capacity. However, since the oil temperature can and does differ from coolant temperature and sometimes by a significant amount, the oil coolers are used to bring it back down to a more reasonable temperature. Hence, though the oil temperature might be at 280, that does not mean the coolant is also.
Also, oil can absorb far more heat than water, but it releases it more slowly as well.
I agree somewhat with the 75% number, but I think overcoming friction accounts for much less than 20% of the energy of combustion. If I recall correctly, the number is around 10%, but it's been awhile. Nonetheless, that is a small detail and of course what you were trying to get at is that friction turns into heat that must be evacuated by the oil. We're in agreement here.
08-23-2007, 12:55 PM
#115
If you answered no to both of the above 2 lines, please explain to me where distilled water is 2 to 3 times more effective at heat transfer than the glycol based solution. Or are you saying that water is 2 to 3 times more effective at heat transfer than 100% glycol, which nobody would run?
And please explain how any of this has anything to do with the question that was asked.
Secondly, it's been said in this thread that glycol helps cooling, when in fact it hinders when compared to water.
Also, is it worth the lower boiling point for only 8F cooler coolant? I think not...I will take the year round safety and protection of an EG based coolant.
So you're trading off increased cooling capacity (which would be useful anytime you drive your car) for a few moments more time before your coolant boils over when your radiator fans fail (which would happen.... uh... rarely). If you want peace of mind, get yourself some good gauges so you can actually see what's going on in your car before things get to the point where coolant boils. You can also get a higher pressure radiator cap, to increase the boiling point to the same levels as the 50/50 mix.
08-23-2007, 02:17 PM
#116
The funny thing is that the heat transfer of water vs glycol was never a question at all. The OP stated that as fact.
The problem is that there is no way to directly measure "bubbles in the engine"... The only evidence we have is what is observable - the heat transfer efficiency, and the extra wear induced by corrosion. One of those is fairly easy to determine, but the second is a long-term effect so none of us have the resources to do that kind of testing. The only way we can come to a conclusion is via empirical evidence....
The problem is that there is no way to directly measure "bubbles in the engine"... The only evidence we have is what is observable - the heat transfer efficiency, and the extra wear induced by corrosion. One of those is fairly easy to determine, but the second is a long-term effect so none of us have the resources to do that kind of testing. The only way we can come to a conclusion is via empirical evidence....
You don't even have heat transfer efficiency because you're only measuring temnperature at one point. You'd at least need to measure the radiator inlet and outlet temp and even then you'd only get a feel for radiator heat transfer efficiency, not heat transfer efficiency between the cooling media and the engine surfaces ... in general though if efficiency increases between the cooling media and the engine surfaces you'd expect to see an increase in the rise between the inlet to outlet temperatures of the cooling media.
To simply say that the outlet temp is lower so the system is more efficienct without providing any more data is frankly, BS ....
08-23-2007, 02:35 PM
#117
We usually laser the 'stat housing and the rad outlet for transfer efficiency, but that can also indicate a lack of flow, which is the exact opposite of what a good reading would indicate.
Best bet is to laser the oil inlet and outlet, the 'stat housing, the rad inlet and outlet and a bunch of points on the housings.
Ultimately, you can learn a lot about what the motor is doing from just the thermostat housing temp (or the temp sensor since it is in the same place), but you have to know the other stuff first for it to be relevant.
Best bet is to laser the oil inlet and outlet, the 'stat housing, the rad inlet and outlet and a bunch of points on the housings.
Ultimately, you can learn a lot about what the motor is doing from just the thermostat housing temp (or the temp sensor since it is in the same place), but you have to know the other stuff first for it to be relevant.
08-23-2007, 03:03 PM
#118
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First off, I do not have to answer to you. So don't question me on what I can post here.
Secondly, it's been said in this thread that glycol helps cooling, when in fact it hinders when compared to water.
That can only be answered based on your local temperature range. But for most climates, I would say as long as you don't have to worry about freezing, it is definitely worth going without antifreeze. Your car will not hit the temps required to boil the pressurized water in the radiator unless you had something wrong with your cooling system. And running a mix of 50/50 with a slightly higher boiling point would not prevent the resulting issues from a broken cooling system.
So you're trading off increased cooling capacity (which would be useful anytime you drive your car) for a few moments more time before your coolant boils over when your radiator fans fail (which would happen.... uh... rarely). If you want peace of mind, get yourself some good gauges so you can actually see what's going on in your car before things get to the point where coolant boils. You can also get a higher pressure radiator cap, to increase the boiling point to the same levels as the 50/50 mix.
08-23-2007, 03:43 PM
#122
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No, not safely. Remeber, the entire system is trying to reach stasis. If your oil temp gets more than 10°F above the coolant and your coolant is already at operating max, you are wandering into a dangerous place.
You are still confusing temperature and heat.
Also, oil can absorb far more heat than water, but it releases it more slowly as well.
I researched my numbers and they were correct. Of the total combustion energy available, 37% goes into the coolant as heat, 38% goes out the exhaust as heat, 5% goes into the engine as friction, leaving 20% as power output. The 5% is 20% of the remaining 25% after the heat loss, as I said.
You are still confusing temperature and heat.
Also, oil can absorb far more heat than water, but it releases it more slowly as well.
I researched my numbers and they were correct. Of the total combustion energy available, 37% goes into the coolant as heat, 38% goes out the exhaust as heat, 5% goes into the engine as friction, leaving 20% as power output. The 5% is 20% of the remaining 25% after the heat loss, as I said.
I am not confusing heat and temperature. There is a difference in heat energy and the temperature reading of a medium; I am well aware of that. I am merely stating that an oil temperature reading of 280 degrees does not mean the coolant is also at that temperature. Granted it could be and as I admitted above I have a poor feel for whether it will or not, but it can also not be. The coolant could be exposed to more heat energy than the oil while at the same time the oil has a higher heat capacity, but the coolant is also better at rejecting it through the radiators than the oil is through the oil coolers and so could be at a lower temperature than the oil. Somehow I think we're just arguing two different things though...
I'll give you the energy breakdown of the engine; that sounds about right. I read your statement as 20% of the total energy was lost to friction, meaning only 5% of the combustion energy was available for powering the car and the accessories. 5% of the total energy of combustion lost to friction sounds about right.
08-23-2007, 03:44 PM
#123
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08-23-2007, 03:47 PM
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Where is your proof of this? You have myself, DeViLbOi, MazdaManiac and TeamRX8 telling you the same thing - the temperature of whatever the liquid is running through your cooling system doesn't mean ANYTHING unless the block, head, etc. are also cooler. I could use peanut butter as my engine coolant, if it's 190 degrees when I measure the temperature - does it mean it's taking more heat away from the engine?? The temperature of the liquid is irrelevant, what matters is how much heat is it actually taking off the engine - this is what I, along with several others, want to know. And don't link to that Redline website.
The increased pressure of a radiator cap will increase the boiling point. Learned that too. The fact that you owned cheap parts on your cheap rustang is irrelevant.