Evaporative cooling question

[veggie]

On my latest project I was thinking of using and evaporative water tank for engine cooling. Just like the original Listers.
That project can be seen here ... https://listerengine.com/smf/index.php?topic=9572.msg109839#msg109839

While they do take a long time to heat up, once near boiling they keep the engine at the optimal operating temperature.
And warm up time can be controlled by the size of the tank.
I will most likely use a pump for circulation rather than rely on thermosyphon, although that simplicity appeals to me also.
My question to all those who use an evaporation tank:...

Do you mix glycol to the water in your systems ?
And if so, does the glycol boil off with the water or does the mixture get slightly more concentrated as steam leaves the system?

[32 coupe]

When I used thermosyphon on my twin I had thermostats on the water out manifolds.
I placed the bottom of the tank level with the return line to the engine.

A pump will not allow real thermosyphon action.  It may work better in your application though.

I can't answer the glycol question but I would think the water would evaporate leaving the glycol
behind.

[32 coupe]

I did want to add that I have had great success with the after market "race" Honda radiators.
Usually about $100 or less on ebay with an included fan.
I have found on my projects that a 12" fan won't cool nearly as well as the 14" version.

I would put a thermostat on your project. Quicker warm up times amd more consistant running temps.

Good looking project !

[veggie]

32coupe,

Thanks for the feedback. I will see how I can fit a thermostat into the system.

[Powdermonkey]

32coupe,

Thanks for the feedback. I will see how I can fit a thermostat into the system.

Veggie- I've got a thermostat on one of my units (that is currently running off of tap water).  Opens and closes as needed.  BUT...I added a radiator bleeder off to the side of it, so that I could get water throughout the jacket before a start-up.  I can take a picture if you wish.  Just PM me. 

On my main twin, I run 50 gallon hot-water tank, with the insulation stripped off.  Strictly thermosyphon.  Sure, it's steaming by the end of the day, and I add water about every 2 weeks.  SHOULD the water level go below the "upper" fitting, the system simply turns into a condenser.  Not a problem.  Still works.  Again, I can take pictures if you wish. 

[cobbadog]

Your proposal is not called evaporative cooling it is simply thermosyphon which needs no help from a pump. The water pump will hinder the thermosyphon flow and circulate the water too quickly and not allow your engine to warm up to running temp.
Something that has been mention on this site before when running a thermosyphon system is the use of a thermostat to quicken up the warming of the engine. One unit mentioned was an inline thermostat from a Land Rover. If your system is for a permanent set up up then yes glycol will be a good idea. If it is to be a rally engine and running for a couple of days then drained then no glycol would be needed. There was a good tip mentioned above about having a bleed off system to fill the engine with coolant before starting, this is essential as if there is no coolant in the engine then the syphon cannot start. I am not sure if the thermostat would be best fitted on the outlet from the head to the tank so that when you fill the tank the engine fills automatically which to me is the safest option.
Let us know what you decide.