Am no expert on cooling systems, but a couple of things seem to me obvious. A pressure less system is easier/cheaper to manufactue, and hopefully less (or at least much later then the manufacturers life of the vehicle definition) susceptible to leaking which somehow still occurs. If cooling issues do happen, so either a leak or even a thermostat issue, it gives you more time as it provides longer protection than a traditional system. If it then also is less toxic that would certainly be another bonus, especially if you have to work on these cars.

But I do agree there are no major issues and I would see it more as an improvement. I guess everyone agrees here (who never had cooling system issue).

 

On the other hand, a few downsides to a pressureless system are increased probability of cavitation/flow delamination in areas of high fluid velocity- pump impellers, small passages, sharp corners etc. There is the increased possibility of microboiling/fluid vaporization on critical hot surfaces- the last possible place it should be allowed to occur.

Either of these phenomena will do more damage than corrosion or a slow leak. The nominal 15lbs pressure in a conventional system does a lot more than just raise the boiling point of the coolant.

 

So you are saying that where Evans claims to reduce/prevent micro-boiling is actually the reverse, i.e. worse than with traditional pressurized coolant? Interesting, can you provide a link with more details on this?

 

I found this link a while ago, when I first heard of this Evans stuff, makes interesting reading.
It has been written by Applied Chemical Specialties, Inc.

No-Rosion Products Technical Questions and Answers

After reading this, and also the cost involved with conversion, I decided against it!

Like others have said, "If it ain't broke don't fix it"

 

It looks like the ideal coolant would have the advantages of the waterless stuff, but without the disadvantages.

Advantages seem to be ( sorry to repeat myself )

Higher boiling point and lower freeze rate.
Ability to remove radiator cap without scalding yourself.
Non toxic.

These advantages do not appear to be in dispute, but having read stumpy's link ( good find dude ) everything else is.

Disadvantages appear to be that it results in engines running hotter, instead of cooler, which is particularly dodgy on engines with aluminium heads, or anything else aluminium.

Theres also Mikeys point about nucleate boiling creating hotspots and increasing wear rates/ corrosion at those points, some of which are due to reduced flow, and others due to the coolant properties .

The need for at least 97% removal of conventional coolant to avoid negating any benefits, a percentage beyond most peoples reasonable achievability without an engine strip and rebuild.

The cost, versus that of water/antifreeze 50/50 mixes.

Hell i'm not going through this step by step, i'll be here all night.

Just read stumpy's link and make up your own minds.

It's off my shopping list.

I'm still waiting for a fluid that has the advantages of this stuff, but makes the engine run cooler instead of hotter, and removes it's other issues as well.

Science, bring it on

 

I have no evidence one way or the other on how the Evans product will operate in a zero/ambient pressure system, I was making observations on how a conventional coolant would react under the same conditions.

The study linked by Stumpy might suffice on the nucleation/micro-boiling subject.

I see no real world drawbacks to having a pressurized system, so modifying a system to run zero pressure offers no advantage IMHO. Being able to remove a rad cap without scalding is nothing to get excited about- how many people try to remove them with an engine at full operating temp anyway?
.

 

The link indeed sows that there is less micro boiling with evans at 0 pressure, unfortunately they don't show any pictures, that would have been nice.

No-rosion is of course a competitor in cooling products, and the performance of cooling will largely depend on the basic cooling design of the car itself. I don't know anything about the car they tested it on and under what circumstances; all I know is that it does work for the XKR without the elevated temperatures as suggested in the article. Nevertheless I do have my reservations with Evans as said earlier, otherwise I would have already done it.

For me however it is logic that a pressure less system would be more advantageous for reasons mentioned earlier.

 

Most people know that removing the rad cap on a warmed up car requires the precaution of using a rag, however some find out the hard way.

People normally remove them under such circumstances to top them up if they notice the temperature is a bit high, or if something has gone wrong, in which case the water may be much hotter and more dangerous than normal.

Not having to use a rag is not an enormous advantage, but anything that makes it safer has to be a plus.

I thought stumpys link was saying that micro boiling increased with the waterless coolant, partly because of reduced flow velocity due to non pressurisation.

Apparently it can be offset with higher velocity water pumps.

In light of the findings in that link, i wonder how the XKR that runs it does so without an increase in engine temperature.

It would be interesting to find out.

 

Here is a quote: "Evans advertises a number of performance benefits in the area of reduced coolant nucleate boiling. In our research, we found that with proper conversion to the Evans product, its elevated boiling point did yield a 46% reduction in localized cylinder head nucleate boiling."

This is a big improvement, as Mikey pointed out, on 50/50 systems (so with water), it’s important to keep a pressure, as otherwise you increase the nucleate boiling, which is bad.

The current Jaguars do have much better cooling systems then in the past; they are able to rung flawlessly in dessert temperatures, and probably still have some reserve build in. So in moderate environments there is so much reserve that with the waterless system you still run at designed engine temperatures.

So if you were running en beefed up engine in Death Valley temperatures at race speeds, you’re stressing the cooling system much more then when cruising in Canada’s winter conditions for instance.

The XKR is running in normal conditions in a moderate climate, for normal street driving, so considering the reserve in the clooing system does explain why you don't see elevated temps.

What attracted me was the lower nucleate boiling, even if it would be at slightly higher coolant temps, as it would give some extra reserve at the higher performance levels I’m at, but never proceeded for the reasons mentioned, even though my interest stays.

 

You are quite right on the Nucleate boiling reduction Avos, my apologies.

I think i got inhibitor deposition mixed up with nucleate boiling.

I guess theres no hope for me lol.

 

But an interesting discussion all round and no apparent need for flame suits or pancake bunnies.

 

I for one know a bit more now than i did previously about cooling systems, but then i didn't know much in the first place

 

I know this is a old topic but being a new member and wanting to do the conversion to the evans coolant brought up a few considerations after reading.

First thing I notice is the applied chemicals specialties "report"
I wouldn't call it a report because it is made by a direct competitor of evans.
No Rosion is a brand name used by the manufacturer of coolant fluids Applied chemicals !

Just my opinion:
Hot water = steam = pressure build up, resulting in strain on hoses and plastic parts within the cooling system.

Steam can also form pockets where no coolant can go in resulting in hot spots

Water = corrosion = damage, example the heater valve on S types.
every single engine block I have ever opened had some form of corrosion showing inside the engine no matter if they were cast iron or aluminum.
the water pump is also a part that's subject to damage as a result of corrosion.
next one I can think of cillinder head gasket, corrosion and presure are the main reasons for the head gasket to blow.

The reasons why I want it in my S Type:

No presure ( or very low) so no strain on hoses and plastic parts
No water is no corrosion
No steam so no chance on hot spots

running temperatures are regulated by the cars thermostat so would be equal within a few percent to that of water based coolant.
The same goes for cooling fan they are regulated by thermostats, and every car has a temperature light or meter a worn part causing the engine to overheat would be noticed and means you have to stop and check your engine !!!!!


heat transfer should be better if coolant is in direct contact with all parts of the engine.

Please remember, just my opinion a year after the last post was made in this thread.

 

Jurgen-

How do you intend to modify the cooling system on your S-type to ensure that no pressure develops as the engine and coolant temperature increase after engine start?

Mike

 

Hi Mike
I don't, the water less coolant doesn't expand as much as coolant containing water when heating up.
Modifications are unnecessary the liquid itself takes care of the lower pressure.

 

Sorry, this is false. Best do some more research.

 

I don't know if my input is going to be helpful or not. So I will just tell the story and let you decide. Some years ago I had a hot rod customer that had a 1951 Ford with the original flathead engine. Some of you might remember that the flathead V8's were notorious for overheating. After going through the usual routine of flushing the radiator, checking the thermostats (2), etc. ,he decided to have me replace the coolant with the Evans water substitute. Did it work? Well, in a way it did. We were on a long road trip with the car club, and it never did boil over. However at around the 150 mile mark it melted the fiber timing gear. So, it went home on a flatbed anyway. But....it never boiled over.

 

My single experience with Evans has been positive. Installed it ten years ago in a non-turbo Chrysler PT Cruiser. Installation was not that difficult. I drained all the coolant from the radiator. There was probably still some coolant left in the block. Filled the system with pure 100% antifreeze and ran it for an hour or so. Then drained and refilled with Evans'
There was still some trace conventional coolant in the system. To remove the water in the conventional coolant, I left the radiator cap loose enough to emit any steam. For a period of several weeks I added Evans to the system, maybe less than a quart. After this, the coolant level remained fixed to this day, some 70K miles later.
In addition, I changed the OEM thermostat to a cooler 180F. Coolant temp under the OEM was constantly over 200F (much like current Jaguar). Now coolant temp runs 180-185F. The motor's ECU has not set any fault codes, etc.

 

that would mean the engine overheated and that wasn't noticed by the driver !!!
No Temp gauge or light in that car ?
So it wasn't the coolant causing a problem, but a technical problem with the engine.

the simple fact that evans doesn't boil until 180 degrees doesn't mean you can run the engine up to that temp, the temp gauge in my S type always sits straight in the middle no matter what sort of coolant is in the cooling circuit if it starts going up that means something is wrong and you have to stop and check.

the advantage evans coolant has would be no immediate damage as a result of boiling

Why is this false ?

 

Jurgen-

All liquids change in volume as the temperature increases and decreases. This is without going through a physical change of state from liquid to vapour or solid to liquid.

As a car engine warms from ambient to normal operating temperature, the coolant expands in volume. The pressure created is limited to around 15 psi via the pressure release function of the radiator cap. If waterless coolant is installed, the pressure will still rise to the system limit no different than conventional coolant. Nothing in the info from Evans says otherwise. The excerpt you've quoted talks about the behaviour of coolant as it changes physical state, ie from liquid to vapour. Apples and oranges.