Evans waterless coolant

[Jonathan Kay]

Liquids are effectively incompressible: no change of volume with change of pressure.

And expansion with temperature is as in #124 above.

And we don't know that the pressure in the coolant is different between the two coolants.

Jonathan

[rj]

Exactly and as it's incompressible it will result in a pressure rise, which will be relative to the air volume in the system.

(if you had no air at all the pressure would go balistic)

When people report next to no pressure in the waterless system, then I asume the expansion coefficient is less.

Having a temperature raise of 5 degrees would not be an issue; if anything the engine runs slightly too cold as I have a seventysomething degrees PRRT and the temperature used to be rock steady at 75 degrees on trackdays where the car was abused by up to four drivers - or in other words: Starded in the morning and hooned throughout the day.

[Jonathan Kay]

When people report next to no pressure in the waterless system, then I asume the expansion coefficient is less.

I've never seen any measurement of pressure in the liquid. I have seen the reports of lower pressure in the gas space above. The difference between the two coolants in that respect is the properties at the gas-liquid interface (as it is for their different boiling points), not the coefficient of bulk expansion of the liquid phase.

Jonathan

PS: I don't know what the difference is in pressure between the two liquids and I can't do it by thought experiment. Can anyone else, please?

[rj]

In a closed circuit the pressure will be the same all over the circuit regardless if the medium is not the same. The compression of the differnet parts may be different, but the pressure will remain the same. You can not have one pressure in part of the circuit. Just like if you have two resistors in series, the current will be the same. If the resistance is different the voltage drop will be different but the current will not. - Or two ropes "in series" the force will be the same, although the stretch of each may not.

[revilla]

Only strictly true when there is no flow ... e.g. you will see a higher pressure just downstream of the pump that upstream, but I'm just being pedantic, it won't be enough to be relevant to the discussion here!

[anthonym]

if that's a reference to when I set fire to it with a match; it was a bit disconcerting. However, I have been running my duratec (Mondeo ST200 Estate V6)  Mk2 year 2001) on it for some time now and with that article open to the side here I can offer the following:

The last point worth noting is that you cannot top up with anything other than Evans, so make sure you carry a litre or so with you everywhere! 

THAT is why I don't have it in my 7 yet. That said you CAN use water in emergency, you just have to start over when you get home. 

The other part which I struggled with is that the engine runs hotter than its normal operating temperature on the Evans fluid. If you aren't a gauge watcher or have zero mechanical sympathy then you will probably be okay but I couldn't have the gauge running that high, it just isn't right!

Yes my (analogue) guage is a tad warmer, which at the beginning was a bit disconcerting, but I have adjusted to it.

On the operational side of things, the engine gets up to operating temperature very quickly, unnervingly so actually. I think this was down to the more stable and conductive nature of the fluid (I was told by the engineer from Evans but I can't remember) allowing the heat to circulate and pass through the fluid easier and hence, faster.

This one surprises me because yes now he mentions it, it does warm up more quickly and I'd say once run, cools down more slowly so that upon restart, say after a long lunch, operating temp is resumed very quickly - and hereabouts sub zero is common over Winter during those lunches. I suppose with short journeys less time with a cold engine is a good thing. 

The downside to this is that to work properly, there has to be less than 1% water content in the coolant which involves lots of purging of the system with the correct cleaner, a very messy and time consuming process.

Ok, well I had Ford do that - they made a complete hash of the first attempt, only removing about 50% of the original coolant. I established this because they used only 50% of the Evans that should have been. So that was expensive. Then I bought the gadget for measuring water % and it's zero as far as I can tell, so that's good.

Top ups: yes have had to add a little, perhaps once or twice; I can't help wondering where/how it went. 

The attraction for my Seven would be this:

water you get less problems with air pockets and hot spots in the water jacket.

but at 19 years old my Seven has managed this far so it all seems a bit academic - unless it would significantly improve cooling at low speed (under 40) when there is insufficient air flow during mountain climbs. 

pressure: only a slight woosh when removing the cap when hot.

[rj]

Andrew,

So true. If the viscosity is significantly different then the pressure loss in the system will also be significantly different - but how fast does it flow? Not fast, I reckon, when an old Ford could circulate the water sufficeintly with no water pump.

[auyt]

Interesting thread, if this helps anyone my 7 has a freshly rebuilt 1968 Lotus Twin Cam. At the suggestion of the engine builder I’m using Evans.

I had read and heard of issues with race engines running Evens due its viscosity , but after covering 200miles I have had no issues. And yes I have 1 litre just in case.

Mine is set it up with an overflow and the level does change but by a very small amount if at all.

And as an added precaution against TC water pump issues it’s fitted with a Davis Craig electric coolant pump love how it works and manages the system.

 

 

[rj]

In my case the reason for not using it is that I don't want anything flamable just above the primaries exit from the cylinder head.
 

[garybee]

I'm looking forward to leaving my current job next year.  That'll give me lots of time for other projects, one of which will be measuring how effective this stuff is as a coolant.  I figure a couple of big lumps of aluminium (preheated and with a few thermocouples mounted), a small coolant circuit (also with measured temp) and pump will quickly show how good a coolant it is.  I have a very strong suspicion about what it will show (even their claims are mostly obvious nonsense) but it's always nice to test for definitive proof of course.

[John Vine]

I'd be very interested to see your results.  They would be even more interesting if you plan to repeat the experiment with (a) water, (b) water plus water-wetter, and © a 50/50 water/ethylene glycol mix.

Based on the known specific heat capacities of these fluids, I think I could make a reasonable stab at the likely results!

JV

[auyt]

This video may answer some question, interesting result

[John Vine]

(

)

Thanks for that.  I always like a practical demonstration.  But all that little demo illustrates is that Evans has a lower vapour pressure and a higher boiling point than either water or an assumed 50/50 water/EG mix -- which, of course, is a known property of propylene glycol and one of the claimed benefits of Evans.  But it tells you nothing at all about what is the main requirement for a coolant -- namely, how well it transfers heat. 

I'm also puzzled why the 50/50 mix (assuming water/ethylene glycol) should boil before the water, given that a 50/50 water/EG mix boils at around 110C at atmospheric pressure.

JV

[auyt]

I can give an example from my own experience with Evans as to how fast it transfers heat. Basically my 7 has an aluminum radiator about the same size as the original escort unit as my car is an 85 build. A Davis Craig electric water pump system. When you turn the engine off after a run it is at its optimum temp of 87c, the system controller continues to run the fan and the water pump until the system sees 76 degrees, the speed this happens is less than 30 seconds and you can see the direct reading gauge move as it does so.

One of the most import aspects of Evens it effectively eliminated localised boiling at the top of the piston bore to cylinder head.

As for the 50/50 coolant mix, my understanding is the glycol is anti corrosive lubricant for the water pump and the key is cold climate anti freeze.

The radiation pressure cap gives the higher boiling point. Lots of guys i know with vintage cars run demineralised water with water wetter added to improve the cooling effect.

 

[John Vine]

... the speed this happens is less than 30 seconds...

I wonder how fast it would be with (a) water (b) water plus water-wetter, and © 50/50 water/EG?  Based on the differing specific heats, I would suggest all of these would be faster than Evans.

...it effectively eliminated localised boiling at the top of the piston bore to cylinder head.

Yes, that indeed is probably Evans' most believable claim.

JV

[auyt]

It will be interesting when you do do an experiment and see the results

This article may help

https://www.hotrod.com/articles/glycol-or-water-coolant/

The specific heat capacity of ethylene glycol–based water solutions is less than that of pure water; in a 50 percent solution, ethylene glycol’s specific heat capacity compared with pure water is decreased at least 20 percent at 36 degrees and about 17 percent at 200 degrees. Propylene glycol, another common coolant, has an even lower specific heat. Assuming a 100-gpm (gallons/minute) coolant flow rate and an energy loss through the coolant system of 189.5 hp, the water temperature increase would be 10 degrees, the ethylene glycol water mix would gain 20 degrees, and propylene glycol would gain 33.3 degrees...............

................Bottom line: A large-tube aluminum radiator filled with pure water and using at least a 20-psi cap is by far the best heat-transfer setup, provided the vehicle is not subject to freezing conditions. Be sure to add a corrosion inhibitor when running pure water.

 

[Wrightpayne]

The fact it is highly flammable is enough to put me off. Any leak / overflow is a fire risk I’m not prepared to accept.

 

[garybee]

Auyt - Thanks for that.  I will make sure to post details of my intended setup for comment before I do it.  I think it would be nice to hear any comments about shortfalls/oversights beforehand.  I don't think the type of radiator is too critical however, so long as it is the same for all coolant tested.  I'm quite looking forward to doing this actually, maybe we can have a bit of fun with it and hopefully avoid the usual internet unpleasantness. 

[rj]

The fact it is highly flammable is enough to put me off. Any leak / overflow is a fire risk I’m not prepared to accept.The fact it is highly flammable is enough to put me off. Any leak / overflow is a fire risk I’m not prepared to accept.

+1

[auyt]

Interesting point you have raised, and an eyebrow as well, however after some googling for me the advantages out way the flammability issue.

There appears to be more of a chance of the first fire causation being fluids other than coolant, fuel for example. Articles about this 50/50 Glycol state that once the water evaporates its just as flammable. Also the engine operating temps are not high enough for it to ignite straight glycol

From the EVANS MSDS  the Flash point is 120C. https://images-na.ssl-images-amazon.com/images/I/71k9VBQ8B7L.pdf

Researching what "flash point" means I found this article, which is interesting because it actually sites the example we are talking about

http://www.ilpi.com/msds/ref/flashpoint.html

For example, gasoline has a flash point of approximately -40 degrees C (-40 F) and is more flammable than ethylene glycol (antifreeze) which has a flash point of 111 degrees C (232 F) in closed cup tests.

The other thing to consider is both the FAA and EASA have mandated the use of waterless coolants for fluid cooled aircraft engines this is done for a separate reason ie operating temps being higher than coolants can cope with, but the flammability aspect would be taken into consideration.

and if your having trouble sleeping after reading the above and while I have gone off topic this is an article by Garrett Engineers on what Auto fluids burn should be just the ticket

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

[rj]

On a K-engine there's a "water rail" that runs just above the primaries from back to front. The primaries are more than 120 degrees.

There always is a potential leak where the water rail meets the cylinder head. I've had it leaking there more than once.

As an ex-fireman this is more than enough to put me off. I accept that there's always a risk, but no need to challenge faith.

[Jonathan Kay]

I figure a couple of big lumps of aluminium (preheated and with a few thermocouples mounted), a small coolant circuit (also with measured temp) and pump will quickly show how good a coolant it is.  I have a very strong suspicion about what it will show (even their claims are mostly obvious nonsense) but it's always nice to test for definitive proof of course.

I think it would be nice to hear any comments about shortfalls/oversights beforehand.  I don't think the type of radiator is too critical however, so long as it is the same for all coolant tested

It would be great to see some experiments.

We know that the thermal capacity of Evans Waterless Coolant is less than that of conventional coolant. So I'd encourage you to concentrate on experiments that don't spend too much time on that, although you'll probably show it along the way. The more you can make your rig like a real Seven's engine the better. That could include using the same materials as in the block and radiator and getting the flow rates as similar as possible. The logical end point of that is doing the experiments on a real engine. The downside of that of course is the cost of the proprietary product. How much is a couple of engines' worth? I might put in my share...

... especially if we can turn the outcome into a wager with the winnings going to the Club charity. But I'd warn everyone joining in that we also already know that engines run hotter on Evans Waterless Coolant than on conventional coolant.

Jonathan

[Jonathan Kay]

One of the most import aspects of Evens it effectively eliminated localised boiling at the top of the piston bore to cylinder head.

Is that something that you observed or is it taken from the suppliers' claims?

I haven't seen any evidence that this occurs in modern engines that aren't faulty.

Thanks

Jonathan

[Jonathan Kay]

The other thing to consider is both the FAA and EASA have mandated the use of waterless coolants for fluid cooled aircraft engines this is done for a separate reason ie operating temps being higher than coolants can cope with, but the flammability aspect would be taken into consideration.

I'm only aware of notices that apply to some specific Rotax engines and they allow several responses, including monitoring coolant temperature and using conventional coolant.

EASA 2007-0155
FAA SAIB NE-05-84R1

Jonathan

[auyt]

As experiments go I’m running evens and with the electric water pump, the system maintains 87c any thing over 90 sets of an alarm and light.

Initially on my freshly built engine the thermostat housing had a tiny weep with the odd drip straight onto #3 exhaust with no issues

I think the basis of this discussion is based of ones own risk assessment of using Evans, for me the anti corrosion higher boiling point in an old engine.