Cooling system

[leopard]

I might be slightly behind technology about cooling system. Is there better cooling system for the engine other than radiator? Having compared the different effect of using water coolant versus plain water. Water coolant performed far better than plain water, the temperature level didn't go higher than quarter of the scale and it went down again.

Using plain water in emergency water coolant out of stock might effect the engine temperature increased up to a half of the indicator scale, especially in the climbing road or horrible traffic jam. Does anyone have experience to explain this?

[schmenke]

Disadvantages of plain water (compared to coolant/water mixture):

Water has a relatively low boiling point. The addition of coolant raises the boiling point, providing better thermal absorption.
Water has a high freezing point. with just plain water the engine block in my car would have cracked about a month ago ;)
Corrosion. Coolants typically contain corrosion inhibiters.

[Magnus]

The addition of coolant raises the boiling point, providing better thermal absorption.
Yes, but the addition of coolant also lower the heat capacity of the liquid. There are very few, if any liquids that have such high heat capacity as water. water has 4,18 kj/kg*K while for example glykol has 2,4. But glykol has a boiling point of 198 C. This means that in the end the heat capacity aspect and the boilingpint makes it quite even.

[Daniel]

Yes, but the addition of coolant also lower the heat capacity of the liquid. There are very few, if any liquids that have such high heat capacity as water. water has 4,18 kj/kg*K while for example glykol has 2,4. But glykol has a boiling point of 198 C. This means that in the end the heat capacity aspect and the boilingpint makes it quite even.
Pretty much. When people watercool PC's if they want to go for maximum cooling you're best off with water. But up course in an open system where the water doesn't get heated as much as in a car's cooling system you get algae growing and that just makes it worse. But back on topic :)

Another thing which annoys me is why people don't say more often to use distilled water in the radiator rather than tap water? Got a low water warning going up a steep hill near home this morning so went to a place to buy some pre-mixed coolant this afternoon and what did I end up with at home? Pure coolant :mark: Off to get some distlled water in the morning. Fun fun fun.

[Zico]

There is a coolant product on the market called "water wetter" which is supposed to increase cooling performance by reducing surface tension, not sure how acurate the claims they make are.. but theres lots of info on here with regards to the cooling capabilities of water, glycol and of course the product itself.

Explained in great detail here.. http://www.racerpartswholesale.com/redtech3.htm

[leopard]

Disadvantages of plain water (compared to coolant/water mixture):

Water has a relatively low boiling point. The addition of coolant raises the boiling point, providing better thermal absorption.
Water has a high freezing point. with just plain water the engine block in my car would have cracked about a month ago ;)
Corrosion. Coolants typically contain corrosion inhibiters.

Very true, what I remember was water enhances corrosion while also notice that water has a relative lower boiling point. I didn't see a direct correlation between corrosion and higher temperature of engine until you posted that this was coupled by the low boiling point of plain water.

Distilled water might help to minimize the negative characters of the plain water. I just considered that a pack of 555 worthed more than buying coolant or distilled water. :)

[Daniel]

Buying distilled water has never been so hard. Went into a supermarket and they only had ironing water which has fragrances and other additives in it. Went into a hardware store and they didn't have any. Went into Halfords and they didn't have any but did have battery water which is suitable. Just need to remember that the yellow stuff in the boot is washes fluid and the blue stuff is coolant.

[rah]

Buying distilled water has never been so hard. Went into a supermarket and they only had ironing water which has fragrances and other additives in it. Went into a hardware store and they didn't have any. Went into Halfords and they didn't have any but did have battery water which is suitable. Just need to remember that the yellow stuff in the boot is washes fluid and the blue stuff is coolant.

You can also use DeIonised water if that is more available.

[Daniel]

I think that's what the battery water is. I was just expecting to be able to buy distilled water in a supermarket like in Australia :p

[leopard]

Are you surely not talking about battery liquid ? :)

[Daniel]

battery water is a totally different thing to battery acid.

[airshifter]

Distilled water is easy to find here.


I might add that the pressure in a cooling system is usually more than enough to keep a car from boiling over. Despite the fact that you actually lose some cooling ability, the antifreeze is mostly just for that freezing issue and lubrication.

If you look at your pressure cap and then figure out the boiling point, sometimes they are really too high from the factory. I'd rather have a car boil over and force me to stop rather than getting so hot that it causes major damage before boiling over.

Not that I want either to really happen. :D

[Daniel]

but surely for the average idiot driver something that's going to keep the coolant liquid for longer is going to be better. It would be better for the car to boil over easier but how many people actually watch the gauges? Whenever my car gets vaguely warm I put the heater on with the fan on full to help keep it cool but it only gets "warm" in traffic so it's not normally an issue. What temperature if any is "normal" for your water temp? My car usually runs at 70c in summer and about 65 in winter. Only seen it go to about 90 in traffic and after a few minutes of having the heater on it had gone down to about 80.

[Zico]

My neighbour who happens to be a taxi driver, told me that temperature stability is one of the main features he looks at when choosing a new taxi vehicle... especially more so when you have 2 different materials for the block and head (differing expansion/contraction rates). He believes it to usually be the difference between 150k or the 400k total miles he expects from his engines.

His logic makes sense to me..

[leopard]

Supposing drive the car in normal condition, relatively free from traffic jam and continued climbing road, runs in optimum speed (which each car has it vary), radiator works normally and having more fresh air from fan would make it go down before it boiled.

Stopping the car would be good idea than forcing the engine runs in that so high temperature. Usually car works in various temperature consumes more fuel than those of constant temperature. But, it is still better than possibility of car being boiled over. :D

[drew3007]

If you find yourself in trafic jams and you car is getting too hot, look at your radiator fans. Make sure they are turning on when they are supposed to. When you see your temp gage going up and down, it is supposed to. There are a couple different levels of cooling that happen in your car. When you car is first turned on, your coolant pump is running, but it is just circulating in the radiator because your thermostat is not open yet. Once the engine reaches a certain temp, the thermostat is opened and the coolant is pushed through the engine. That is the first drop you see in the temp gauge. Then, if the engine reaches a certain temp with coolant running through it, the fans are turned on. That is the second drop you see in temp. If you don't get that second drop, or you do and it still creeps back up to a dangerous temp there are 2 possible problems.

1. You have a dual fan system and one of the fans isn't working. If you don't get the second drop at all then the fans just are not comming on.

2. You have too much coolant in your water/coolant mixture. As they said before, water is better as cooling than coolant (anti-freeze) is.

You can go to your parts store and ask for coolant test strips. These will measure a variety of things, including your mix percentage. Depending on your local conditions, you will want anywhere from a 70/30 - 40/60 water to coolant percentage. The 70/30 for hot weather, the 40/60 for very cold weather (avg temp of -20F for that extreme mix).

Sorry this was so long, but engine cooling can be complicated.

[leopard]

We get acquainted with a ready use coolant sold in gallon that no need any work to make the water and coolant admixture. Each different brand may offer different quality of coolant agent and its percentage of admixture.
Manually calibrating the proper composition between water and coolant seems to be impractical repetition of works.

Refilled drinking water after passing UV ray treatment was also alternative I was told that it has better protection cooling down the engine than plain water.

[Malbec]

Try mercury, the Soviets used to use it in some of their compact nuclear submarine reactors. I'm sure it has a higher specific heat capacity than water.

[Daniel]

I love it how you say "Try mercury" so casually :)

[leopard]

that's cool.

[airshifter]

Try mercury, the Soviets used to use it in some of their compact nuclear submarine reactors. I'm sure it has a higher specific heat capacity than water.

Don't be so sure. Water has one of the highest specific heat capacities of any liquid. I'm fairly sure Mecury has a low specific heat capacity, which makes me wonder why it would be used in such an application.

My guess would be that the mercury would act as a buffer, as most marine applications use heat exchangers for cooling.

[Magnus]

Mercury has very low capacity; only 0,14 kJ/kg*c
Water has, as I pointed out eralier in this thread 4,18 kJ/kg*c
The low heat capacity is one of the reasons it is used in termometers.

[leopard]

True and therefore that idea sounds like carrying coals to Newcastle