Waterless coolant

[cobham cobra]

Thought this might be of interest. I saw this waterless coolant used in a car programme the other day and then watched the J Leno interview (the link's below). The two things I thought may interest us is a) it works well in a non-pressured system and b) because there’s no water, there is no corrosion which could be extra useful for those with aluminium engines or heads. The downside is it’s not cheap, but apparently it never needs replacing or topping up.
   http://www.evanscoolants.co.uk/news/jay-leno%27s-garage/1

[Robin A Woolmer]

One of my US Customers is going to use it in his new engine, i understand it has good wetting capability so better heat transfer.
   
   Robin

[nikbj68]

Dad uses (Castrol)4Life in the Greyhound; seems very similar, boiling point 180°C, freezes at -42°C, etc.etc. and is around £16 for 5 litres compared to £60+ for the Evans. Another benefit is the 'litmus' effect that it changes from it`s normal pink to yellow should you have head gasket problems. The other noticeable difference is that despite the name '4 Life', it is effective for 10 years, but the Evans would need to be in the car 30 years more to pay for the difference!!!

[rsk289]

I have used Evans in my cars for many years now - Healeys, Mustangs, Cobra - I even put it in my 'modern'* BMW last year.  When I drain it to do other work on the car, it always amazes me how smooth and clean the water passages and hoses seem to be.  Never had any boiling over either, but judging by the literature I'd be in serious trouble by the time it got to boiling point!
   Roger

[Flyinghorse]

I have been thinking about the Evans tonight & googling it.
   
   It does seem a bit "snake" oil, so possibly fitting for a cobra...but at the end of the day a 50/50 glycol water mix under a 7psi rad cap pressure will boil at 130 degc,not 100degc.
   
   What is important(along with mass flowrate) is the specific heat capacity of the coolant fluid, and water is a fluid with a high specific heat capacity. I don't think Evans state the engines run cooler but just say they don't boil. If you have an inefficient flow system, or poor /clogged radiatorthen even with the evans the temperatures can get high,so whilst you may not have any pressure in the cooling system, it may well be very hot.
   
   I picked this up from the Toyota supra forum and it makes sense:
   The amount of temperature rise (what we call "delta T across the engine") is given by the formula:
   
    delta T = P / (m x Cp)
   
   
    Where:
    P = the heat power rejected to the coolant (kW).
    m = coolant mass flow (kg/s)
    Cp = Specific heat capacity of the coolant (J/kg.K)
   
   
    The thing to take away from this is that "m" and "P" are pre determined by the engine, so effectively delta T (the temp rise across the engine) is inversely proportional to Cp (the specific heat capacity of the coolant). Therefore if you switch coolant to something with a lower Cp value, the delta T will increase. For water the delta T is usually 6 to 8 deg C, for 100% glycol it would be about 12 deg C.
   
   Whats not given for the Evans is the Cp,and given a water glycol 50/50 mix boils at 130degc with a small pressure rad cap (7psi) if you cant keep your engine cool then theres an issue with your coolant flow rate or radiator efficiency.
   
   I am not saying the Evans is a bad idea, as many may like the "fit & forget" and non expansion aspects,but then again its effectively the same as 100% glycol, which is a lot cheaper and to which you can add low cost water wetter.
   
   I also thought it interesting that some fluids used in solar energy heat transfer are supplied from the same address as Evans:
   Evans Cooling Systems UK
   Unit 5,
   Europa Way,
   Swansea West Business Park,
   Fforestfach,
   Swansea
   SA5 4AJ
   and Hydratech:
   
   http://www.hydratech.co.uk/contactus.html
   at same address
   
   They at least state they sell etheyne glycol /propylene glycol....
   Graham

[ak1040]

Hi John , I have used shell 4 life in my Mk4 and tested it to see if there would be any difference in performance , giving it a fairly rigorous test of a fairly long and varied journey , so far it has proved to make the car run fairly cool at approx 80 degrees ,last night over dinner I had a discussion about the cars temp and how it is now running but I forgot to mention in this discussion that I had used shell 4 life in my car , having gone onto the forum this morning and seeing Cobham Cobra and now knowing who Cobham Cobra is I will report back to you John at dinner tonight about the Shell 4 Life as we are both at present on the AC Tour in the Pyrenees with Dee and Christine our wives , thanks to Jasper who has done all the organising of this trip .

[3.5 Pints at the Bar]

Graham makes some valid and interesting points. I wonder if the specific heat capacity changes with temperature (or at critical temperatures) for the waterless coolant? What concerns me is that the high boiling point would remove one of the plus points of water-based coolant: Localised boiling can cool any hot-spots by utilising water's high latent heat of evaporation. The AC Weller engine tends to run hotter at cylinders 5 and 6 by design and so these may be vulnerable if the engine is below par.
   
   On the plus side, lower corrosion and no limescale would be a welcome change. But if the AC water-pump is weeping, then coolant costs might exceed the fuel bill!

[3.5 Pints at the Bar]

I see that Evans' website tackles my point (mentioned above) about the benefits of localised boiling. They basically say that if the temperature is high enough at a hot-spot, instead of bubbles of steam helping to remove heat (via latent heat), it can become a continuous layer of steam preventing heat transfer.
   
   In the AC engine, coolant stagnates at the rear, allowing corroded alloy flakes to build up and make the coolant flow even worse. I suspect that steam may be produced around the top of cylinder 6 under these conditions leading to rough running.