Water-less Antifreeze in a Thermosyphon System

[Roger Frazee]

Has anyone used water-less antifreeze in an early antique car with a thermosyphon (no water pump) cooling system?  I'm thinking of trying it in my Overland.

[MCHinson]

I have no experience but you might want to try doing a search. This subject has been debated several times in the past. With a quick search, here is one of the previous posts:  http://forums.aaca.org/topic/175809-waterless-coolant-experience/?tab=comments#comment-1120924

 

My suspicion is that this question is one of those that you can ask two people and get three different opinions on it...

 

[DavidMc]

I have a friend who tried it in a car with thermosyphon cooling, it did not circulate and the supplier then confirmed that it is not suitable.  There is a statement on the web site stating that it is not suitable.  All previously discussed in detail on this site.

[Spinneyhill]

One well known brand of waterless coolant has a specific heat about 75% that of water. Specific heat is a measure of how much energy it takes to raise the temperature of a standard amount by 1^o and also how much energy is lost when that amount cools by 1^o. Thus a lower specific heat means less efficiency as a coolant, which thus means you need more coolant to pass the hot place to cool it by the same amount. A thermosyphon system would be a bit dodgy with such coolant I would think.

 

I think it is a crock and would not use it in any cooling system not set up for it. The system must have a high-efficiency pump and large radiator. A system set up for water would, in general, be undersized.

[Restorer32]

Customer tried it in his '21 Silver Ghost with near disastrous results.

[edinmass]

If you read the fine print even an ounce of water left over in the system will have a significant impact on the waterless coolant to cool properly. So the system must be totally dry to work correctly......not an easy task. Also, it will leak much easier than water will......thus a car that is not leaking with regular coolant may leak like a sive with the waterless stuff. Look at the cost and I don’t see any benefits. Just run anti freeze and change it out every three years. 

[Alfa]

I do not have personal experience of waterless coolant, but have followed the exploits of some others in the UK. Laboratory analysis revealed that a proprietary brand here was 100% ethylene glycol (neat antifreeze in other words). This will have a higher boiling point than a water based coolant, as advertised, but a lower specific heat capacity as already mentioned here. So there is little or no benefit from a cooling perspective. In fact a system relying on convection currents (thermo-syphon) may well be made worse. The system will indeed run to a higher temperature without boiling, but will transfer less heat to the radiator whilst doing so.

There is a further unfortunate side effect, coolant ejected from the overflow pipe is more slippery on a road surface than oil, so a bit distressing for motor cyclists ! For motorsport in the UK, we now have to fit catch tanks for the radiator overflow to avoid coolant spilling onto the track surface.

[Roger Frazee]

Thanks to all for your thoughts and advice.  I have refilled my cooling system with conventional antifreeze and distilled water and will not look back.

 

[Alfa]

The right decision in my humble opinion!

 

Adam..