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Waterless coolant -- cool!
https://slantsix.org/forum/viewtopic.php?t=23524		 Page 1 of 3
Author:  SlantSixDan [ Fri Jun 08, 2007 11:10 am ]
Post subject:  Waterless coolant -- cool!
Coolant's being discussed on a Mopar mailing list I'm on, and a few members have pointed to Evans NPG+, a completely waterless coolant not made or intended for blending with water. The system operates at no (or very slight) pressure, and is said to allow what would ordinarily be considered very elevated coolant temperatures without the usual attendant pinging and overheating. The theory behind this claim (water-blended coolant permitting localised boiling/vapour layers interfering with water-to-metal contact, leading to detonation) is quite sound. The complete corrosion prevention, nonexpansive/non-solidifying freezing (it just thickens, but is still pumpable) and lack of cooling system pressure (easier on our classic radiators) are all very attractive. The folks who mention it on the list have been very happy with it so far in their Mopars of various age and type. The website is rather poorly designed (zoom in; they use a font too small to read easily), but it makes for a great deal of interesting reading. Looks like they're equipped to make custom water pumps, too.

We need someone with an "extreme" setup (turbo...?) to torture-test this stuff and see what happens!
Author:  emsvitil [ Fri Jun 08, 2007 12:30 pm ]
Post subject: 
The stuff has a specific heat about 70% of straight water (normal 50/50 mix is 80%)..

So I would think you'd need a larger radiator to reject the heat.
Author:  AnotherSix [ Fri Jun 08, 2007 12:36 pm ]
Post subject: 
Well that looks like it might work. Theres snake oil, and then theres what can actually be done for a high enough price. If they actually deliver on the claims, it sounds like a big step forward.

There is definately more to it than just coolant temp. Eliminating those little clinging bubbles could really lower the actual temps in the material of the head, even if the coolant temp is the same or a bit higher.

This could change what would be considered overheating as well. What we are stuck with now is just whatever the boiling point of our setup is. The real issue being the vapor from boiling allowing hot spots. And you can only get so close to boiling before you shut down, or it just boils after shutdown. I suppose oil temp might be the new limiting factor, not that you would want to run too hot anyway.

So, is this the real deal? My cars hold just over 4 gallons each, except the honda thats under warranty. Thats about a $150.00 coolant fill with shipping. Anyone ready to jump?
Author:  ceej [ Fri Jun 08, 2007 12:52 pm ]
Post subject: 
Not I. I was trying to get back into the math of Heat Transfer to fluids. It's Friday. I think I need a beer!

Finding a decent way to computeThermal Conductivity in organic mixtures with water seems to be based on experimental modeling rather than plug and play formulas... I've become an internet conversion and computation addict! :shock:

I managed to dig through a handbook and find some moderately useful stuff for salts, but nothing for organics and solvents.

It looks like the heat capacity and thermally conductive properties of this stuff, coupled with the viscosity is going to be less than Water/Ethylene Glycol, except where it's normally pretty warm. Here in the summer it might be OK, but it's pretty viscous stuff on a chilly morning.

CJ
Author:  63gtcv [ Fri Jun 08, 2007 6:30 pm ]
Post subject:  Cool it
I might be intereased but my 74 Duster run only about 140*, even on the warmest days. I can let it idle and it will barely crack 180*. Maybe after others have tested further,I would consider it for my 63 Dart.
Author:  Aggressive Ted [ Fri Jun 08, 2007 7:42 pm ]
Post subject: 
Same here, 140 to 145, with a 195 stat. I wonder if it would run warmer with this stuff? That would be nice!
Author:  Matt Cramer [ Sat Jun 09, 2007 10:02 am ]
Post subject: 
Hmmm. I've seen that stuff tested in Grassroots Motorsports; they were pretty impressed with it.
Quote:
We need someone with an "extreme" setup (turbo...?) to torture-test this stuff and see what happens!
You're in luck. Right now my turbo Dart has its coolant drained out while swapping in a radiator, and I'm going to be dyno testing it when I get it back together. I may have to fill it up with this and see how it does!
Author:  SlantSixDan [ Sat Jun 09, 2007 8:41 pm ]
Post subject: 
Quote:
The stuff has a specific heat about 70% of straight water (normal 50/50 mix is 80%) so I would think you'd need a larger radiator to reject the heat.
I'm not so sure. In fact, I kinda doubt it, for a couple of reasons-

Anecdotal/practical: The folks I've known long enough to know they're not BS artists, who have tried this stuff, report their cars run cooler with the NPG+ coolant than with ordinary coolant/water — without having changed to a different radiator, water pump, or anything else.

Theoretical: The NPG+ may well have a lower specific heat than ordinary coolant, but I suspect that's usually not the primary determinant of cooling efficacy for any given system. The question that needs to be answered is whether the full heat carrying capacity of water-based coolant is actually available and being used in our cooling systems. The theory of localised boiling and barrier vapour layers suggests to me that it is not. If you have such a vapour layer due to localised boiling, then liquid water cannot contact the metal at that location, and the steam that is in contact with the metal cannot transmit the metal's heat to the surrounding water. I am not a thermodynamicist, so I emphasize this is just me thinking the system over and possibly making erroneous assumptions and/or drawing erroneous conclusions.

But, this question reminds me of the recent brake system balance thread, in that it doesn't matter how super-duper-good your coefficient of friction is between the front brake pads and discs if you cannot access and use that friction because the rears lock up before you can apply as much braking force as you'd like: Suppose (picking numbers out of the air) that the vapour layer effect means you only get to use 60% of your water-based coolant's heat carrying capacity. Suppose that by eliminating the vapour layer problem, the NPG+ permits you to use, let's say, 95% of NPG+'s heat carrying capacity. Using your figures of 0.8 (50/50 EG & Water) vs. 0.7 (NPG+), we would be comparing 0.6 x 0.8 = effective heat capacity of standard coolant of 0.48, versus 0.95 x 0.7 = 0.66, giving NPG+ the advantage.

Whether you buy this mental math depends on whether you want to look at heat movement through the entire cooling system, or just in the radiator. I can see looking at just the radiator if the limiting factor in the system were an under-specced radiator (or one that started out OK but has lost effective heat transfer capacity with age and usage).
Author:  SlantSixDan [ Sat Jun 09, 2007 8:47 pm ]
Post subject: 
Quote:
Same here, 140 to 145, with a 195 stat. I wonder if it would run warmer with this stuff? That would be nice!
Reports are that engines run cooler with this stuff. There's still something the matter with your system, that you haven't yet fixed.
Author:  SlantSixDan [ Sat Jun 09, 2007 9:02 pm ]
Post subject: 
Quote:
it's pretty viscous stuff on a chilly morning.
H'mm. I don't know enough about viscosity measurement to offer anything but conjecture. Yep, NPG+ is numerically more viscous than 50/50 EG + water at every temperature, but I am not sure whether the extra viscosity is significant in terms of any actual operating characteristic encountered in unmodified vehicular cooling systems. There'll be higher pump drag at cold coolant temperatures, but I don't know how much more, and if the increase is significant, I see it as a transient condition along the lines of higher drag in the engine oil pump, power steering pump, transmission pump, etc., due to cold fluid: the coolant probably won't spend much time at temperatures low enough to create significantly higher pump drag.

I do wish the four tables at the bottom of http://www.evanscooling.com/main25.htm included standard 50/50 data, and that the temperature range went above 0°F. Perhaps I'll write to Evans and see how coöperative they are providing data beyond what's on their site.
Author:  AnotherSix [ Mon Jun 11, 2007 2:31 pm ]
Post subject: 
I have to agree with Dan that it is not just the amount of heat that a coolant can absorb, or carry, but it's ability to transfer that heat as well. That was your point, right? The heat has to move from the cast iron or aluminum into the coolant and then from the coolant to copper or aluminum. That film of bubbles starts at a rather low temperature an I believe is a major factor.

The heavier weight may or may not be an issue. I have used water pumps with extra blades and closed off the back of the impeller with a disk to get extra flow. A heavier fluid might actually get pumped better. I think you would have to test this aspect. There are way too manner factors that affect a pumps performance, right down to clearances, that it will likely vary with engine family. Not to mention the rpm that it will spend most of it's time at.
Author:  440_Magnum [ Mon Jun 11, 2007 3:11 pm ]
Post subject: 
Quote:
Quote:
The stuff has a specific heat about 70% of straight water (normal 50/50 mix is 80%) so I would think you'd need a larger radiator to reject the heat.
I'm not so sure. In fact, I kinda doubt it, for a couple of reasons-

Anecdotal/practical: The folks I've known long enough to know they're not BS artists, who have tried this stuff, report their cars run cooler with the NPG+ coolant than with ordinary coolant/water — without having changed to a different radiator, water pump, or anything else.

Theoretical: The NPG+ may well have a lower specific heat than ordinary coolant, but I suspect that's usually not the primary determinant of cooling efficacy for any given system. The question that needs to be answered is whether the full heat carrying capacity of water-based coolant is actually available and being used in our cooling systems. The theory of localised boiling and barrier vapour layers suggests to me that it is not.
<snip>.
In a nutshell, what you are suggesting (greater heat transfer from engine metal to coolant, but lower specific heat of coolant) would imply exactly what the Evans website says: engines are more EFFECTIVELY cooled, even though they may indicate a higher operating temperature. The coolant itself will get hotter because its both a) absorbing more heat from the metal, and b) has a lower specific heat so therefore undergoes a bigger temperature change to move the same amount of heat.

What that doesn't jibe with is "reports of engines running cooler" with Evans coolants. I just don't buy that. All things being equal EXCEPT the coolant, the gauge should read higher even though the cylinder heat metal might be very much cooler.
Author:  SlantSixDan [ Mon Jun 11, 2007 5:16 pm ]
Post subject: 
Well, the discussion with Evans is off to a very bad start. I sent them the pertinent parts of my two lengthy posts in this thread, and what I got back (and all I got back) was this (misspellings are theirs, not mine):

===========================
" Sorry to say I'm not a scientist and cant give you any answers other then
our coolant works to help lower internal metal temps."
===========================

Here is my reply:

Wow. That's really not good enough at all! Perhaps you can pass my enquiry along to someone in the organisation (Mr. Evans, for instance) who _is_ a scientist and _can_ answer my questions? You are about to lose *every* shred of credibility your product might've had with me (and the many automotive forums for which I write) if the best you can do is "I'm not a scientist, trust me, it works".
Author:  440_Magnum [ Mon Jun 11, 2007 5:44 pm ]
Post subject: 
Quote:
Well, the discussion with Evans is off to a very bad start. I sent them the pertinent parts of my two lengthy posts in this thread, and what I got back (and all I got back) was this (misspellings are theirs, not mine):

===========================
" Sorry to say I'm not a scientist and cant give you any answers other then
our coolant works to help lower internal metal temps."
===========================
Eww. Not promising at all. Hopefully its the usual mis-match between the dumb sales droids and the rest of the company.

While I certainly believe that people often do find wonderful engineering solutions without fully understanding why they work, youd think that by the time the product has been on the market for years and has undergone a revision to improve performance that they'd have FIGURED IT OUT!
Author:  Matt Cramer [ Tue Jun 12, 2007 5:54 am ]
Post subject: 
Quote:
===========================
" Sorry to say I'm not a scientist and cant give you any answers other then
our coolant works to help lower internal metal temps."
===========================
Ugh. My main job is answering email inquiries from customers, and if I wrote back an email like that I'd risk getting fired. First rule of customer service: If you're asked a question and can't answer it, find someone who can.
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