Added individually, coolant & water won't mix?

[JHZR2]

I buy concentrate and distilled water so it's easy enough for me to make my own mix. I usually do.

It's reasonable to expect vastly different concentrations in there for a bit. Pour the two together and you definitely see striations (you can make them out in the attached pic) that don't go away by themselves. I don't know enough about how the water flows through, but it's reasonable to assume that the slugs of liquid in the hoses stay in relatively consistent concentrations there. If that's also the case in the radiator too, I can see it taking some time to fully mix.

But to get maximum heat transfer, surely they want turbulent flow in the heat exchange surfaces. As a result, there will always be some front-back mixing.

The wild card is if flow is turbulent in the engine but slows and becomes more laminar in the radiator. I'd suspect that could effect mixing.

But in the end it will mix. I'd lose no sleep.

But if I was filling a car that was going to sit for a while and not be readily used, I'd probably pre-mix just
To be double sure the inhibitor concentration was right everywhere.

Best practice but not always critical.

 

[earlyre]

Originally Posted by DoubleWasp
A water pump is about as close to a blender as it gets. It's larger than a blender blade, has more blades, and is powered by a fueled engine. The average engine moves around 70-130 GPM at cruise. Low circulation my behind. Many vehicles have restrictors in the heater core lines to prevent the coolant flow and pressure from blowing out the heater core.

When coolant moves through an engine, it does so at high volume, it is sucked, squished, forced into thin core tubes, heated, cooled, shredded by the water pump, subjected to high centrifugal force, etc.

I can't think of a better system to blend two liquids together.

basically what i wanted to say, but said way better than i could think of!

so..lets see..my old sable...full system held ~3gal. using double wasps figures.. lets say 100gpm,(right in the middle) 100gpm/60sec=1.67gal/sec, so, the whole volume of the system gets cycled a little over every 2 seconds.... mind you this is all back of the napkin/spitball math, but that should mix things up pretty well. not to mention create enough flow to draw fluid out of any dead end passages.

 

[Hall]

How 'bout this ? Using the logic presented, how come the water portion doesn't boil off ? I mean, it's "separate" enough, right ?

 

[RooflessVW]

Originally Posted by hallstevenson
How 'bout this ? Using the logic presented, how come the water portion doesn't boil off ? I mean, it's "separate" enough, right ?

Because the boiling point of water is raised in a sealed system under pressure.

 

[Mad_Hatter]

Originally Posted by rooflessVW
Originally Posted by hallstevenson
How 'bout this ? Using the logic presented, how come the water portion doesn't boil off ? I mean, it's "separate" enough, right ?

Because the boiling point of water is raised in a sealed system under pressure.


Handy chart...even with a less than perfect 50/50, the boiling point is well above the normal operating temp of 190~220 with a 15psi cap.

 

[FCD]

Originally Posted by Ed_Flecko
I've heard that the circulation of a car cooling system isn't anywhere near as robust as the lubrication system. Because of this, coupled with the difference in specific gravity of coolant and water, you should always use premixed coolant and water or, at the very least, premix your own before adding the mixture to your cooling system.

I've heard if you add coolant and then water (or vise-versa), the two liquids may never mix thoroughly, due to differing specific gravity and poor circulation, to provide proper cooing, lubrication, protection from corrosion, etc.?

Further, I've heard that by "flushing" your cooling system with tap water, poor system circulation will mean that some of the minerals of the tap water will stay at rest in the system where corrosion (and then problems, etc.) will begin. You're contaminating a delicate system (heater core, etc.) with minerals, etc., that is was never designed to handle.

In short, the closer you keep your cooling system to OEM...the less failures you're likely going to encounter in the future.

Does this sound accurate?

Thank you,
Ed


Absolute nonsense!

 

[Yah-Tah-Hey]

The more preposterous the mumbo-jumbo, the quicker do people line up to swallow it.

 

[The_Eric]

The only way that there's even a shred of truth to it, is on the old thermosiphon systems. How do I know? Found out the hard way... Deere B (2 cyl), poured in the antifreeze first, then the remaining water and fired it up. It ended up starting to get hot... The 'ole boy that used to stop by and bs with us (and knew EVERYTHING old tractor and industrial equipment related) told me not to do that - all I did was pull the bottom plug and drain it into a bucket, then dumped it right back in the engine. After that all was well.