90/10 mixture - corrosion issues?

[Riptide]

I have a supercharged car and was planning on going with a 90/10 mixture of distilled water and motorcraft gold coolant next spring for the intercooler. Intercooler and heat exchanger are aluminum.

Now I've been doing some reading and am seeing all sorts of stuff about how running distilled water with little or no coolant will cause corrosion problems. Is this a buncha nonsense or should I reconsider my plans here?

Tried the search function but it didn't come up with anything regarding distilled.

 

[Boomer]

By mixing coolant a glycol coolant with water, you do three things.

1. Increase the boiling point above that of water.
2. Decrease the freezing point below that of water.
3. Provide significant corrosion protection for engine metals.

Generally, you get into the area of the "best" of these properties around 50/50. Pure glycol coolant has a worse freexing point than just water for example. So unless you have information in your owner's manaual to the contrary, it would seem to me to be judicious to use a 50/50 blend.

 

[user52165]

Is a 90/10 ratio safe in Billings, MT?

 

[Riptide]

It's safe in the summer.

I want minimal antifreeze and max water in the mixture to help exchange heat. Water exchanges heat better than antifreeze leading to lower intake air temps. That is why I want to use such a 90/10 mix.

Then I read this thread here:
http://www.svtperformance.com/forums/terminator-talk-229/814023-distilled-drinking-deionized.html

And it made me wonder if that is a good idea or not.

 

[user52165]

Originally Posted By: Boomer
By mixing coolant a glycol coolant with water, you do three things.

1. Increase the boiling point above that of water.
2. Decrease the freezing point below that of water.
3. Provide significant corrosion protection for engine metals.

Generally, you get into the area of the "best" of these properties around 50/50. Pure glycol coolant has a worse freexing point than just water for example. So unless you have information in your owner's manaual to the contrary, it would seem to me to be judicious to use a 50/50 blend.


+1

 

[Riptide]

So how much coolant needs to be in the mixture to guard against corrosion? Is 10% sufficient?

 

[Torino]

Yes, 10% is sufficient for a short time. I run that mixture in two muscle cars with aluminum heads and water pumps. I DO change it yearly. John--Las Vegas.

 

[dailydriver]

Originally Posted By: Riptide
It's safe in the summer.



...and in a heated garage/storage space in the winter.

 

[Wilhelm_D]

Originally Posted By: Riptide
I have a supercharged car and was planning on going with a 90/10 mixture of distilled water and motorcraft gold coolant next spring for the intercooler. Intercooler and heat exchanger are aluminum.

Now I've been doing some reading and am seeing all sorts of stuff about how running distilled water with little or no coolant will cause corrosion problems. Is this a buncha nonsense or should I reconsider my plans here?

Tried the search function but it didn't come up with anything regarding distilled.


If you’re in an area where it won’t freeze, you can run straight water with an additive.

The advantage of the water over the coolant is heat transfer, ethylene glycol is simply not as effective as water at getting the heat out of the engine and into the air through the radiator.

The reason why you use distilled water is to avoid adding minerals to the mix. One way or the other minerals are going to go out of solution and/or contribute to electrolysis. A couple of products come to mind:

Lubegard Kool It

RedLine WaterWetter

Lubegard Kool It Comparison

I would give a slight preference to the Kool It.

 

[Al]

In general water will pick up more heat than the mixture in a small specific area...but The overall heat removed will be identical when comparing water with a water/coolant mixture.

The reason for this is that although the water picks up heat better at the engine) it looses is slower in the radiator so in steady state there will be no difference. During the short period of heatup; water will keep the engine a litter cooler until steady state is reached...so that's a very minimal advantage.

Even if you double the flow rate the results will be the same. Ultimately the only thing that matters is the size of the radiator.

But again if the area of the surface area of the intercooler is the small percentage of the heat load in the engine..the water mixture will be better.

 

[Rand]

Originally Posted By: Al
In general water will pick up more heat than the mixture in a small specific area...but The overall heat removed will be identical when comparing water with a water/coolant mixture.

The reason for this is that although the water picks up heat better at the engine) it looses is slower in the radiator so in steady state there will be no difference. During the short period of heatup; water will keep the engine a litter cooler until steady state is reached...so that's a very minimal advantage.

Even if you double the flow rate the results will be the same. Ultimately the only thing that matters is the size of the radiator.

But again if the area of the surface area of the intercooler is the small percentage of the heat load in the engine..the water mixture will be better.


can you find a source for this?

thats counter intuitive if water transfers heat better it will do so at the engine and radiator.

 

[JZiggy]

We need to get out the old Heat Transfer textbooks -- lots of complex issues here from the block-to-coolant interface, coolant-to-rad interface, flow rates, etc.

Note the huge different in Prandtl number between water and oil:
http://en.wikipedia.org/wiki/Prandtl_number

 

[Chris142]

As soon as you add the 10% antifreeze to the Distilled water it's no longer distilled so thats not a problem. I don't think 10% antifreeze is enough to prevent Corrosion though.

 

[Wilhelm_D]

Originally Posted By: Rand
can you find a source for this?

thats counter intuitive if water transfers heat better it will do so at the engine and radiator.


The reason why water transfers heat better is because it is a better conductor, which works both in the enginge block and in the radiator.

 

[Wilhelm_D]

Originally Posted By: Chris142
As soon as you add the 10% antifreeze to the Distilled water it's no longer distilled so thats not a problem. I don't think 10% antifreeze is enough to prevent Corrosion though.


The antifreeze coolant contains no minerals, which is also the reason we use distilled water. So if you have 0 ppm calcium in the distilled water, you have 0 ppm calcium in the mix with coolant, unless calcium is a component of the coolant additive package.

 

[Riptide]

I was hoping to get away with running 100% distilled water with maybe some water wetter additive. During the summer.

Unfortunately it seems like it's hard to find a clear answer on whether corrosion will be a problem or not. I don't want to take chances on ruining intercoolers/heat exchangers. So it looks like this idea is off the table and I'll have to stick with the 70/30 mix.

 

[91344George]

What does your owner's manual say? The engineers that made your car know best.

Frankly that 10% coolant 90% water sounds like a recipe for massive corrosion .

My guess is the owner's manual says that it should be around 50/50 perhaps 60/40 in cold climates.

 

[johnachak]

Originally Posted By: Riptide
I was hoping to get away with running 100% distilled water with maybe some water wetter additive. During the summer.

Unfortunately it seems like it's hard to find a clear answer on whether corrosion will be a problem or not. I don't want to take chances on ruining intercoolers/heat exchangers. So it looks like this idea is off the table and I'll have to stick with the 70/30 mix.


Straight water or a 90/10 mix will boil at a lower point and will probably foam up quite a bit. I doubt if it will have sufficient water pump lubrication or corrosion protection. If 50/50 is optimal, why mess around. There's a reason its called: coolant / antifreeze.

 

[Shannow]

Back when I was pulling stuff apart all the time, I ran straight water and soluble oil for summer, and antifreeze for winter...little did I realise how bad the soluble oil is at heat transfer, then I switched to Castrol's corrosion inhibitor (also green, just no glycol).

Al's points regarding the mass flow of heat (not mass, but you get the drift) are correct.

However, the glycol has a lower co-efficient of heat transfer, meaning that the Delta T between the hottest part of the system (hot gas), and the ambient air temp needs to be bigger to shift that heat.

An intercooler in an area that never freezes is about the only place that I'd ever say "use water wetter".

 

[chevrofreak]

Originally Posted By: user52165
Is a 90/10 ratio safe in Billings, MT?


Not during winter.