Discussion: Let's talk coolant
 

Mods, if you'd prefer this was somewhere else, feel free to move it; thank you :tiphat:


Let's talk about the science of antifreeze/coolant (TO MY KNOWLEDGE):
Radiator fluid gets beaten to death 6 ways from Sunday, but I would like to see what others' input is on the topic.


The goal of the radiator is to keep fluid temps DOWN, the goal of the fluid is to draw heat away from the block and a side "goal" is to keep pressure UP; It is the reason for higher pressure radiator caps; the higher the pressure, the higher the temperature of the fluid has to get to boil; the goal of that is to keep liquid as LIQUID.
That being said:

Let's accept some basic facts
"Straight water is the best coolant."
As soon as the fluid boils, the rapid expansion of liquid to gas will immediately overcome the pressure of the coolant cap, and the car will overheat almost immediately because steam SUCKS at drawing heat away from something.
Also, even though it is mainly sold as "antifreeze" the real purpose of coolant for MOST the population is to RAISE boiling point, lubricate the water pump, and prevent corrosion even if you use tap water. (Of course not for those who live in places where it freezes over)


So, water boils at 100 deg C, 212 deg F (at sea level)
In a pressurized system, assume 15 PSI, the BP (boiling point) is 120C/248F
In a normal 50:50 solution at 15PSI the BP is 129C/265F
Ethylene glycol (standard coolant's main ingredient) STARTS with a BP of 197C/387F; MUCH higher than any combination of coolant and water (let's assume something like 170C/338 since it's not 100% pure)


So the dilemma is that coolant isn't THE best at drawing heat away from the block, and its regarded as too thick to run straight; AND even the smallest amount of water dramatically lowers the BP of the solution. So what do you run as coolant?



Side option:
Evans Waterless Coolant; BP is at 190C/375F, it's lifetime, and supposedly 100% safe

o,o what?
anyways..umm my honda was close to over-heating couple months ago.
The temp was nearly up to max, but I pulled over and let it go down a bit. On the freeway, however, the temp was not going up dramatically.
When I got home, my dad just said I had like low water or something, and he simply just added um drinking water for a bottle in the thing where the water and or coolant goes I think. Everything seems fine now..

Is this what you are reffering to? lol

^Not at all, you were just running low on fluid, that's a different scenario

For starters, straight water in a cooling system, is not the best coolant for those who think this way.

The cooling system is designed to meet a certain specification. Let's say it's cruising at 70 mph, A/C on, ambient outside temp 120 F for 6 hours with a standard 50/50 coolant mix. Most cars will never need to endure those conditions. So, the standard 50/50 mix will get the job done. If you increase the coolant's BP to 375 F using waterless coolant, the question you need to ask is why do I need to do this when the standard 50/50 mix works just fine? And, if your running a coolant temp of 350F with a waterless coolant, your oem rad probably can't reject that amount of coolant heat. Engine seals may begin to fail, water pump may fail and maybe catastrphic failure of the engine because it's not designed to run at 350 F. Now how hot will your oil temp be? Sounds like pure racing stuff. Using this stuff to remedy an overheating engine is not the way to go. Over heating of the engine, i.e. coolant sytems is probably a problem with the radiator, water pump or partial blockage to the flow of coolant somewhere. Fix the problem and don't use a band aid fix. In summary, the waterless coolant has it's use like in racing, I assume imho.

I've always wondered how machining coolant would perform in a radiator. It adds lubricity and is used for removing heat during metal removal.
I wonder what the boiling point is of a 6% mix of machining coolant is.

I would not try it in my Z, but maybe the Taurus.

I Have no clue but i have a speculation. Per the OEM it only calls for regular coolant and not the waterless stuff. I would call evens up and talk to them about the chemical composition of their automotive product before trying it out, it wasnt on their website. You never know if the VQ engine is made of some metal that counter acts with it, might be good for a ford or chevy but not nissan. Also i dont know if it is allowed to be used for track use. NASA and SCCA didnt specify in the rule book.

I'd have to do a lot more research into how compatible machining coolants are with the various metals and plastics used in the engine before I'd dump it in the radiator. Plus, it sounds terribly expensive.

i just use watever the Z came with. i mean hell... i paid for it, right?

I guess people aren't understanding... I don't have a cooling problem, hell, I have an oversize radiator. This is just a discussion, I throw out the waterless product more as a question as to what you think of the product or the logic behind it

Just as an FYI, race cars, use 100% water, MAYBE with additives, but not a 50:50 coolant solution or anything close to it

DE- is your car a race car? are we really the ones not understanding? :icon17:

I'm not so sure that cooling is actually the main function of coolant any more. Sure, it's important, but corrosion control is just as, if not more, important. The cooling system on the Z seems to be marginal, so a coolant that cools better should be advantageous but I would have to be very sure that anything I used was compatible with the materials used in the engine and radiator. So far, my DD has been handling the S AR heat well (not great but good enough), so I don't plan on changing from the OEM coolant. IMNSHO, an oil cooler would do more good than better antifreeze.

If you're racing, things are probably different and any extra cooling would be worthwhile.

In my mind it is, it's modded in such a way that it should be, lol
I just want to see others' logic

where I live we don't get below freezing so I'm changing over to water and Water Wetter before my next track day. You are not allowed to use any glycol based products on the track and everyone I have spoke to seem to love Water Wetter and has seen reduced temps.

WaterWetter® Tech Info

I use water wetter or... The other one (don't remember the name off the top of my head)