Evans Waterless coolant in V6/V8s?

Discussion in 'General Auto Conversion Discussion' started by pfarber, May 23, 2019.

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  1. May 23, 2019 #1

    pfarber

    pfarber

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    Anyone using Evans in a V6/V8? It seems Rotax had an SB for all 912s to switch, and I've seen a few photos online of the waterless coolant decal near the overflow tank.

    Other than the price, it seems like a no brainer. But I have not read many posts/articles about its use in larger engines.

    Any downsides?
     
  2. May 24, 2019 #2

    TFF

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    That stuff was originally designed for reverse flow cooling with no pressure caps. Had to have different water pump. Evans raced a Camaro in SCCA A Sedan; essentially amateur Trans Am. It was fast. In 1990 it was interesting, not so much today. A friend wanted to use it in one of the last Voyager engines and the more he looked into it, the less magic it had. I forgot what made it stop the show.
     
  3. May 31, 2019 #3

    pfarber

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    The web site shows describes it as basically a drop in alternative. Make sure there is no water and nothing else needs changed.

    Is there another source that I should look at?

    Rotax 912/914 use it out of the box, and from the SB it never mentioned any changes. There are certified engines in certified planes. The FAA did, after a Rotax SB issue SAIB No. NE-05-84R1 which states that the waterless coolant SB did not alter the certified engine.

    So there is precedent that at least the FAA sees this change as not a big deal, do what the manufacturer says.

    One reason I like the waterless coolant is that it NOT pressurized, and the high flash/boiling point means that steam is not an issue.

    The only downside is that Evans recommends a larger radiator due to the less efficient heat transfer. But I think that pressure-less system (not blowing a hose), ability to remove the t-stat, it never needs replacement and it will not corrode internal parts.. there is no water to start the electrolytic process, are all pretty good reasons. Although I am not thrilled about the bigger radiator part.
     
  4. Jun 1, 2019 #4

    TFF

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    My friends aircam is still flying regular antifreeze. Another friend was looking into it for a Cirrus VK30 project that has the only Continental Voyager engine not in a twin, and probably not a half dozen of those engines are flying. Crazy cooling system. After really thinking it through it was not going to be a good match to deal with it. I have known about the stuff since the 90s. There is still a snake oil aspect that I don’t like. If it was really that good, why are we not all using it?
     
  5. Jun 1, 2019 #5

    pfarber

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    $43 a gallon vs $10 for traditional glycol based coolant is the biggest reason. To run an LV3 at 6 gallons is $250 vs $60. So cost would be the biggest.

    I have many concerns with liquid cooling (the bane of auto conversions) so planning on minimizing as many traditional 'gotcha's' seems prudent.

    Granted the coolant would be hard lined to the radiator as much as possible, but there would still be rubber in the system. Removing all pressure from the cooling system seems like a good idea for reliability. Also the higher boiling point would eliminate steam pockets... a definite plus for an engine a high RPM, low cooling air climb outs.

    A minor second plus would be the removal of all coolant based galvanic corrosion. Glycol based formula's simply wear out. A synthetic coolant is once and done.

    I think the combination of an electric water pump (full rated GPM at all time), synthetic coolant (unpressurized system, high boiling point - 375F) and a high flow, low restriction, fail-safe t-stat, and a properly sized, aluminum singe pass radiator that should just about minimize cooling issues. As long as enough air gets to the radiator, the system can be a compact and fail safe as possible.
     
  6. Jun 2, 2019 #6

    wsimpso1

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    I read through their website. They are selling, so let's keep that in mind. They said it is based upon ethylene glycol. That is an alcohol, and can burn very vigorously, just like any alcohol. Dilute EG in water, and like any alcohol, it becomes very docile. And 50/50 in water it pulls heat great from the heads, and moves heat great to the radiator tubes.

    But this stuff, well, we really do not know its composition. I requested a copy of their material safety information, which should give us a pretty good idea what it is, if it will burn with great gusto, etc. I do not know what they will tell me, but I will report what I find. I do know that they tell us it has a flash point of 248 F, which means a simple spark above it when it is 248 F and above will cause it to burn...

    They also tell us we can leave it in forever... Hmm. Standard EG coolants contain corrosion inhibitors and seal lubricants. These are sacrificial chemicals, which give rise to the coolant change intervals with standard coolants. With an absence of water, we might not need any corrosion inhibitors, but unless it is inherently a lubricant for water pump seals, it may need such a thing...

    Ah well, we shall see.

    Billski
     
  7. Jun 2, 2019 #7

    pfarber

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    https://www.evanscoolant.com/faq/about-flammability/

    You didn't read the FAQ, did you???

    Link from the FAQ:

    https://garrett-engineers.com/cases-of-the-month/what-auto-fluids-burn/

    When sprayed onto the steel tubing heated to 1,000°F (a temperature that can occur quite readily in an engine compartment), both the green and pink coolant flashed into flame. This occurred not only at full strength, but also when mixed 50/50 with water, the ratio specified for most vehicle cooling systems. The diluted coolant burns because water evaporates faster than ethylene glycol. Once the water has evaporated, the remaining ethylene glycol ignites.

    Corrosion? You missed this from the website:

    "When heated, water releases a significant amount of dissolved oxygen, but as it cools it reabsorbs fresh oxygen. This cycle leads to the corrosion of metal, which is accentuated in classic vehicles with no expansion chamber.

    Water also acts as an electrolyte if dissolved solids—such as hardness salts (lime scale)—are present. This promotes galvanic corrosion, a process in which two metals corrode at different rates, often causing pitting."

    Evans waterless coolants contain little oxygen and are comparatively poor conductors in comparison to water-based antifreeze, so metal corrosion and coolant degradation is eliminated.

    https://www.evanscoolant.com/how-it-works/
     
    Last edited: Jun 2, 2019
  8. Jun 3, 2019 #8

    wsimpso1

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    Then there is this thread already in place on HBA:

    https://www.homebuiltairplanes.com/forums/threads/evans-waterless-engine-cooling-fluid.22386

    As for pfarber's comments - I did not miss anything. When reading data on something, ask yourself what they are selling...

    The Evans website put on a bunch of info about ethylene glycol coolants (which theirs is NOT) and then, with some hand waving, said theirs is no worse. I have an MSDS coming for the High Performance Coolant.

    Billski
     
  9. Jun 3, 2019 #9

    pictsidhe

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    Evans is propylene glycol based.

    Homework:

    Compare specific heat capacity and thermal conductivity of water and propylene glycol and postulate what effect the differences will have on cooling performance.
     
  10. Jun 4, 2019 #10

    wsimpso1

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    I got the SDS of Evan High Performance Coolant. Doc says:

    Ethylene Glycol 74-90%
    Potassium 2 Ethylhexanoate <4%
    Potassium Neodecanoate <2%
    Sodium Nitrate <1%
    Denatonium Benzoate 40 ppm

    Ethylene Glycol is the exact same stuff we have in standard anti-freeze coolants...
    Potassium 2 Ethyl... is widely used as a corrosion inhibitor in conventional antifreezes. Most corrosion inhibitors are sacrificial - they are more reactive than the products they are "protecting" and are thus used up over time in use. I do not know about this one...
    Potassium Neodec... I could not find anything telling me what it would be of use for in coolant, it is used in catalysts for making polyurethanes...
    Sodium Nitrate is salt, common in things like cured meats;
    Denatonium is the most bitter thing we know of, is used to prevent mammals from drinking stuff that it is in, and is used for that purpose.

    Significant in its absence is anything that is obvious as a water pump seal lubricant.

    Interestingly, the ingredients add up to less than 81 to less than 97%. So somebody is misleading someone about something... That leaves open space for propylene glycol that has been mentioned, and other "magic" chemicals.

    Its flash point is 248F, which is a few degrees lower than straight elthylene glycol. I have no idea how the makers can tell us that their coolant is lower risk than straight ethylene glycol when vapors coming off their stuff lights at lower temps than straight EG. If you run your coolant to exceed that temp, a single spark will ignite vapors, and can thus then burn.

    Another issue presents itself. Automobile engines are thoroughly developed around the temps that they run with water/EG coolants, and never higher than about 250F. If you do run higher than that, you are running risks of some components degrading faster than planned by the engine makers as they do not run up there.

    We normally run thermostats that open at 180F or 192F, but with pressure caps our usual EG/H2O coolants will boil about at the flash point of Evans... If you have a system that takes advantage of the much higher boiling point of Evans, then you may be running in the flammable range of Evans Coolant. Since straight glycol coolants do raise operating temps (water mixes have higher thermal capacities and better heat transfer than straight EG) You might be exposed to this mode.

    One thing that struck me as disingenuous in the Garret paper is their testing at 1000F. Note that is the target temperature, the tested materials were at room temperature. We know that normally aspirated engines commonly run EGT's over 1400F and turbochargers will glow red to orange at continuous high power such as are used in airplanes for climb and cruise flight. Why not use 1400 F for the testing? Looking at the data, 1000 F was enough to light off everything they tried except refrigerants - which evolve nasty chemicals when exposed to flames or very hot surfaces - so why bother?

    One stoogey move was they tested automatic transmission fluid and power steering fluid as if they were different things. Where they were still being run as engine driven accessories, virtually all automobile factories used the same oil in power steering systems as they use in automatic transmissions so that they have one less oil to stock...

    Anyway, EVAN Coolant does not seem to be anything that we have not known about since the 1930's when Rolls Royce was expecting to use EG in their engines. They backed off to water/EG for a bunch of really good reasons, reduced radiator size and thus aero drag being one of them...

    Play with it if you want, but do not expect any big things from it, except running higher temps than water/EG does in the same system, radiator, and operating conditions. To do that, you should accept that if you do run the higher temps it will allow, you are taking a marginally higher risk of undercowl fire and perhaps premature failure of thermally sensitive components.

    Bills
     
    rv6ejguy likes this.
  11. Jun 11, 2019 #11

    pfarber

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    Evans states that their product is not as thermally transmissive as water or 50/50. You didn't read the FAQ either.

    My second post states that I would need a larger radiator.

    There are so many work arounds to make 50/50 coolant work: pressurized system to limit boiling. change the coolant to eliminate corrosion. Steam tubes to prevent steam pockets.

    So far I see no serious case not to use Evans.

    The only downside is a slightly larger radiator. That may be an issue, but my initial design is not a belly mount radiator, rather an engine compartment cheek mount or under the motor.

    But the benefits are so overwhelming.
     
  12. Jun 11, 2019 #12

    Himat

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    Why do you consider pressurizing the cooling system to limit boiling is work around?

    Same about changing the coolant fluid at some set time intervals?
     
  13. Jun 12, 2019 #13

    mm4440

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    Evans recommends high coolant flow to make up for lower heat transport. The air side is the usual problem. With the ability to safely run higher coolant temps without steam blanketing in the cylinder heads, radiator temps can be increased and a smaller radiator is possible. Tested in the 1930's at Wright field, 250 F practical max.
     
  14. Jun 15, 2019 #14

    pfarber

    pfarber

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    The reason I like an unpressurized system is that it would reduce the risk of an overpressure and anything popping. So the radiator cap, rubber hoses and anything welded should not see more than atmospheric pressure. Its a small win, but busting a hose is a real thing.

    Evans never needs to be changed. It never runs out of additives that are required to stop galvanic corrosion. 50/50 is literally pouring corrosive material (water) into your motor.

    The waterless coolants do not transfer heat as well as water, but neither does 50/50. Water is THE BETTER coolant medium but has problems... low boiling point, corrosion.

    As far as coolant flow, I am a big fan of electric pumps. BMW has run them for YEARS.

    I am warming up to the idea of DUAL water pumps. The math is on my side:

    Water pump for used in LV3
    Brand: ACDelco Part Number: 12685257 Weight: 16.13 lbs

    Electric water pump
    Brand:Davies Craig Manufacturer's Part Number:DC-8160 Weight:2.600 lbs.

    The electric pump is rated at 40gpm. One pump on each head should more than handle each head... but that would require some serious testing... or it may work great out the box. Plus you can plumb in a cross connect and now you have dual water pumps. Pumps can set coolant temp from the cockpit or ECU.

    Its a low priority idea. But I can see some benefits of two smaller loops.
     
  15. Jun 15, 2019 #15

    pictsidhe

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    Rolls Royce had overheating problems on straight EG. Those problems went away when they switched to 50/50. I guess they were just too stupid to know how to use straight EG in their engines?

    I once had a tuned car that would overheat in the summer at illegal speeds.
    I could run the heater, which was unpleasant, or run pure water. Speeding up the water pump did not help, neither did an 18psi cap.
    Eventually, I squeezed a bigger radiator in.
     
  16. Jun 15, 2019 #16

    pfarber

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    I reported your post as off topic. Please don't include 6th person anecdotes.

    Do you have anything useful to contribute?
     
  17. Jun 15, 2019 #17

    BJC

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    p:

    What homebuilt airplane are you referencing in post #14?


    BJC
     
  18. Jun 15, 2019 #18

    pfarber

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    BD-4B why?
     
  19. Jun 15, 2019 #19

    BJC

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    Just curious what airplane you are flying with a non-pressurized, Evans fluid, electrically pumped cooling system.


    BJC
     
  20. Jun 15, 2019 #20

    pfarber

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    Do you have any suggestions to remove possibility of overheating/boil off, increase cooling when taxing and climb out and weight??

    I do.

    So far none of the fine folks here have made any significant points.
     

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