Coolant Boiling Question
 

Okay, so as we all know water is more effective at removing heat from the engine than coolant or antifreeze. However, water also has a lower boiling point of 212 degrees and our thermostat opens in that temperature region. 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. (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.

From the Water Wetter technical info PDF:

Dynomometer tests performed by Malcolm Garrett Racing Engines showed significant improvements in coolant temperatures using WaterWetter®. These tests were performed with a Chevrolet 350 V-8 with a cast iron block and aluminum cylinder heads. The thermostat temperature was 160°F. The engine oper- ated at 7200 rpm for three hours and the stabilized cooling system temperature was recorded and tabu- lated below:

50% Glycol / 50% water - 228F

50/50 with water wetter - 220F

Water - 220F

Water with water wetter - 202F




Red Line WaterWetter® does not significantly
increase the boiling point of water; however, increas-
ing pressure will raise the boiling point. The boiling
point of water treated with Red Line using a 15 psi
cap is 250°F compared to 265°F at 15 psi for 50%
glycol. Increasing the pressure by 50% to 23 psi will
increase the boiling point of water to 265°F. Because
of the doubling of the ability of the radiator to transfer
heat, boilover using Red Line treated water is not a
problem as long as the engine is circulating coolant
through the head and the fan is circulating air.
Sudden shutdown after very hard driving may cause
boilover.

We have a 9 bar radiator cap right? I calculated that at 9 bar the boiling point of straight water is 370 degrees F so real boilover isn't an issue. I'm more worried about localized areas where the coolant is starting to bubble.

i've been running around with distilled water + water wetter for a few weeks. No issues. I managed to get the coolant up to 210F a few times, but it cools down rapidly.

There's more to the story..

Except Evans coolant.

Dissolved air can effervesce from coolant, but to get steam bubbles you have to hit 212F.

Also note that nearly half or the rotary engine's cooling is done by the oil.

9 bar would explode the hoses & radiator.
You probably mean 9 PSI.

See Mysql101's post above..
-Bill

Yes I know about Evans. I considered running it for a little bit, but it's just too expensive for the perceived advantages for me.

I also thought 9 bar was a bit high since that's 8.8 atm or 130 psi, but 9 psi seems a bit low. I think the cap might be a 0.9 bar, which equates to around 13 psi. That seems more correct?

Are you people serious? Why don't you just throw some pasta in there too, and have a lovely dinner at the same time?

http://bioengr.ag.utk.edu/Extension/...es/engcool.htm

Read up about engine coolant.

Yeah, we're serious. Do you even know what coolant does? It doesn't cool.

edit: coolant above should read anti-freeze. Either way, coolant doesn't cool as well as water.

I hope you know that multiple car guys I work with are laughing at this thread.

So if coolant doesn't cool we are safe to run our cars without it then...yes? I mean...if it is just there too lube things like the water pump I can just save some cash and run pure air instead. Sounds like a plan! "Roger Roger...What's your vector Victor."

John, these people are experts in their field in Chemistry...look at their graduation picture:

http://upload.wikimedia.org/wikipedi...FoilHat002.jpg

The answer depends on where you live. If you're in an area where it might freeze, you'll need coolant, or your car can get messed up due to the water expanding when freezing. If you're in a location like FL where that rarely happens, you're going to be okay running pure distilled water.

The water pump needs lubrication though, which is why something like water wetter is good (in addition to breaking down the surface tension of the water).

Just so our terms are clearly defined - coolant generally means a mix of 50% water and 50% anti-freeze. The water part cools, the anti-freeze part prevents freezing of the water, and also expands the boiling temps - but at a cost. It doesn't cool as well as using pure water.

The lowered boiling point of using pure water with no anti-freeze generally isn't an issue. Your car isn't going to reach temps anywhere near that unless you're already having issues.

This is hilarious...what part of this doesn't make sense???????

Most of the antifreeze products on the market currently are ethylene glycol base material with additives to prevent corrosion, lubricate seals and water pumps and aid in heat transfer to the coolant from the metal of the engine. Antifreeze should be mixed with distilled water (tap water contains high amounts of minerals such as calcium and iron that can precipitate and coat internal parts) at the ratio of one part antifreeze to one part water. This gives freeze protection down to minus 34 degrees and boil-over protection up to +265 degrees. Never use pure antifreeze in a cooling system without using at least 30 percent water in the mixture. Most antifreeze products sold for the past several years have been the traditional "green" coolant. This type is good for two to three years and up to 30,000 miles. The green antifreeze contains silicates, phosphates and / or borates as corrosion inhibitors to keep the solution alkaline. As long as the solution remains alkaline, corrosion is controlled and the system is protected. Over time, the corrosion inhibitors will be depleted and the corrosion protection is lost. It is for this reason that green antifreeze should be changed every two years or so. Aluminum is especially vulnerable to corrosion and many vehicles have heads, radiators and other aluminum components in the cooling system. If the coolant in an engine cooling system is changed before corrosion inhibitors reach dangerously low levels, corrosion damage is prevented.

.9 bar

Lol, why cant you run only antifreeze?

The only thing hilarious about this is that you're spouting off to me about chemistry degrees, when you're the one who's in special ed.


Think about it. You can't use pure anti freeze without water. Care to guess why? Cause your car would overheat. So explain to me again about chemistry and how glycol magically helps cool better. Don't believe me? Look it up instead of posting silly photos.

Fact is, you don't know squat - and apparently either do your friends who are chuckling behind you. It takes twice as much ethylene glycol, and three times as much propylene glycol to cool compared to straight water.

As I said, antifreeze is useful to prevent your radiator and engine from cracking if you're in locations where freezing occurs. If you're not, then anti-freeze in your radiator is hindering far more than it will ever help.

You'll still need something to lubricate the water pump though. Water wetter to the rescue.

Antifreeze is an additive TO water which expands the max. boiling and freezing points...thats like asking why can't you just eat Kool-Aid powder??

So you're saying that anti-freeze cools better than water, and that anti-freeze is so concentrated that you need water to dilute it enough that it doesn't cool too much? I for one, am glad you're here to teach us about your magical dreamworld where facts and logic don't apply.

Just friggin' amazing.

Do you work for Redline or something?? Honest to God, I'm crying over here laughing at this....

It's not that complicated. As stated in the link I posted, as well as the last post I had, antifreeze is an additive TO water, and is used in conjunction with it to aid in the maximum boiling and cooling points of the liquid that is used to take heat away from your engine. Simple breakdown as in your second post:

Water - 220F

Water with water wetter - 202F

Water + Antifreeze = 265 + degrees

So where does anything your saying make any sense?

I guess it doesn't make sense to you, because you have issues with reading comprehension.

Read my post again:

https://www.rx8club.com/showpost.php...86&postcount=2

Not only are the numbers you quoted different, but your conclusion is reversed.

They put a car on a dyno, ran it for 3 hours at 7,000 rpm, and calculated the resulting temp.

Regular 50/50 mix coolant came out to 228F. Water with water wetter came out to 202F (I consider the number with 100% just water invalid for real world use since you can't run your car that way).


Raising the boiling point of water is going to be useless for the most part. Your car shouldn't reach temps that high if it's functioning normally. Remember, the system is pressurized, so it's not like boiling a pot of water on the stove. 220F isn't going to boil it.

You are wrong....pure water cools better than coolant.....look at the data...there is lots of it around.

EG is used to keep the coolant from freezing..and the additives protect the engine from corrosion and lubricate the water pump

If your "friends" think this is funny they are as malinformed as you.......

spout off on something that you actually know about.............

hey, if you don't want water wetter, royal purple makes purple ice :)

Their numbers show similar results as redline's water wetter:

http://www.royalpurple.com/prodsa/prpice.html

A. Standard mix of water and glycol (antifreeze) - 228° F

B. 50 / 50 water / glycol mix with Purple Ice™ added - 222° F

C. Straight water (no corrosion protection) - 220° F

D. Water with Purple Ice™ added - 200° F


I feel for you, ProCharger GT. After spouting off like that, it's going to be hard to save face.

Wait, coolant actually comes as a powder? WOW!

MazdaManiac posted a link that showed that Royal Purple Ice did not prevent corrosion like WaterWetter did. For that reason, I'd stick with Redline WaterWetter as opposed to Royal Purple Ice.

In that case, you'll find at your local walmart (among other stores) they sell tiny bottles of anti-freeze "refreshers", I forget the name of the product, but it's basically just the lubricants, no glycol.

Not much experience with car engines, but I have had experience with water cooled computers and the exact same arguments come up and discussed at great length.

Ultimately, this is what I've taken away from the whole thing.

Pure water with a surfacent such as water wetter will give you the greatest thermal efficiency, but gives you no corrosion protection. This is especially bad in systems where you have different types of metal such as copper and aluminum in contact with the coolant. You might be better off at first, but when your radiator rots out, you're in for some trouble.

50/50 antifreeze water mix cannot transfer heat quite as quickly, but will keep dissimilar metals from reacting with each other and corroding. It also prevents the coolant from freezing.

Pure antifreeze = you fail at life.

I'm a bit hazy on boiling points for things, as computer coolant cant reach that temp, but if you are thinking about changing your coolant to improve performance, you'd be better off upgrading your radiator, as the difference between coolants is a few percent difference, but an upgraded radiator could get much larger gains in cooling efficiency.

are you high?

coolant/anti-freeze is designed to keep engine temps down, and to resist freezing. its an additive that raises the boiling point and lowers the freezing point...

Computers are different. They aren't going to get as hot, and they're not pressurized.

So we're not as worried about bugs and crap growing in there. But yeah, if you need more cooling, a radiator upgrade would also help.


You haven't been paying attention. Your radiator is pressurized, Why would you care that your coolant can reach 300F? Your car would already be destroyed before that point. As long as your car is operating normally, you'll be fine with straight water. It's boiling point is higher than you seem to think.

Are we still talking about Kool-Aid????

Last I checked...coolant temps rise as heat is removed from the engine. Therefore lowering the point at which the water will boil and add oxygen to your engine is not a good idea.

Maybe you should check again, because you might notice something behind your radiator that helps suck that heat away from your coolant.



That's it folks, I'm tired of repeating myself!

nevermind guys, we shouldn't bother....the numbers are different, therefore the world is wrong....guess i should just leave it alone :rolleyes:

Has anyone here ever even taken a look at the back of an anti-freeze/coolant bottle? There have been some very valid points made here, but there is a reason why cars leave the factory with a water and antifreeze/coolant mix. It has been stated several times here that water mixed with antifreeze/coolant will provide a higher boiling point and lower freezing point than with water alone or antifreeze/coolant alone. I will also stand behind that. Antifreeze/coolant is not a substitute for water, only and additive that increases its maximum boiling point and loweres its freezing point. It isn't a hard thing to understand.

:banghead:

Holy crap Batman we have a winner....

First, malinformed isn't even a word - I believe you are looking for the word misinformed.

Secondly, not once did I ever say running pure coolant was the way to go. Antifreeze + Water changes the chemical properties of the liquid, and it's typically called "Engine Coolant". Why do you people refuse to see this?

Coolant absorbs heat from the block, flows through a radiator which blows outside air over cooling fins, which in turn take heat away from the coolant inside the radiator, which is pumped by a water pump, to keep a constant flow of new coolant going to your engine. This is not new technology.

And what is the efficiency of said device? As my engine temps climb does it instantly bring my coolant temp back down? And I could probably dig around and find all sorts of information but I am lazy...but doesn't normal thermostats open around 180? Why would I want to only give myself 20 degrees to work with before producing oxygen? I may never hit 265+, but I like my odds of getting close to 265 better than 202.

For a guy driving a ford, that's actually a fairly good explanation of a basic cooling system.

:)

That coming from the man that has coolant that crystallizes on him.

Hey, that's on the other engine not mine.

:)

All Mighty Wikipedia says, and I quote:

"The most common coolant is water. Its high heat capacity and low cost makes it a suitable heat-transfer medium. It is usually used with additives, like corrosion inhibitors and antifreezes. Antifreeze, a solution of a suitable organic chemical (most often ethylene glycol, diethylene glycol, or propylene glycol) in water, is used when the water-based coolant has to withstand temperatures below 0 °C, or when its boiling point has to be raised."

We are not saying that water can not be used Moe. What we have been trying to say is that lowering the boiling point is not a good idea. Water Wetter according to mysql's post drops the boiling point from 220 to 202 making it more prone to boiling and or inefficient cooling.

John, read the bold text. I never said that you should only use water.

I'm all for engine coolant, I would never put just water in my car, and I definitely would never use any chemical that would lower my BP.
I need that extra protection, for when I race a grey Dodge Charger (wannabe Chrysler 300) on the highway when I leave work!

Everyone gets this. What you seem to be missing is that water alone has a very high heat capacity. Add antifreeze to it and the heat capacity is reduced.

Are you still with me?

Okay so antifreeze is added to do two things. Most obvious is to lower the freezing point of the mixture. What it does in general is to expand the liquid range so in addition to the freezing point being lowered, the boiling point is raised. The second thing is to provide lubrication and corrosion protection to the cooling system.

Summarizing the above. Adding antifreeze:
Positive:
1) Lower freezing/higher boing point
2) Water pump lubrication and corrosion protection

Negative:
1) Lower heat capacity that pure water

Are you still with me?

Okay so now suppose you live somewhere where it never gets cold enough for freezing to be a problem. Then the lower freezing point is worthless.

Secondly the coolant system is sufficiantly pressurized to prevent boiling. Thus the higher boiling point of water/antifreeze mixture also becomes a non issue. So the only thing to be gained from adding antifreeze is the pump lubrication and corrosion protection. Both of these can be satisfied with a bottle of WaterWetter added to pure water.

I wasn't going to post anymore here, but I can't leave this without an answer.

If you read my post, it never said anything about boiling point. Hell, logic says 50/50 coolant doesn't boil at 220, and pure water isn't going to boil in your radiator at 202.

What the test showed, was a comparison of 50/50 vs water + additive. The same car, the same drive (3 hours at 7000 rpm), and the coolant temp was almost 20F cooler. TEMP OF THE LIQUID, not it's boiling point.

As I said before, unless your radiator fans are broken, running with just water is fine since you're not going to hit the boiling point. Furthermore, because water is more efficient, your radiator will be able to extract the heat from the radiator far quicker than you would be able to with 50/50 of coolant. So that brings me back to what I said before - the higher boiling point of 50/50 doesn't mean squat since you're not going to be hitting it.



This is simple stuff people. What's so difficult to understand?

mysql101 clearly showed a test where water and wetter take more heat out for a specific run, so your car wil run cooler at that instant. Make sense.

haha, this thread cracks me up too. i cant believe so many people have reading comprehension issues. how many times did you repeat yourself mysql?

Think we need MM to come in here with another one of his videos .... to make this pwning complete

All things being equal, that test showed under high load, 50/50 mix was running 18F hotter.

They also showed that with a 15 PSI radiator cap, the 50/50 mix only had a 15F higher boiling temp.

So your choice is to either heat soak your engine, and have a higher boiling temp (only marginally so), or run with water where you can be almost 20F cooler to begin with, AND be able to pull the heat out of the radiator quicker ... so in stop and go traffic, your temps will drop faster.

It's a no brainer! (Assuming you live where it doesn't freeze - or you can change coolant with the seasons).

Point taken...I misread what you had said.

As a person that has boiled an engine...I can not take this risk. Personally...the difference between distilled water and 50/50 is negligible. Living where we do...Water Wetter or even water are not options. My understanding still is that Coolant is similarly efficient at cooling an engine as distilled water without any of the benefits of the coolant.