Kiss is Dead? Thermosiphon Cooling

I saw a post on a forum talking about how good water pumps are now-a-days, and how thermosiphon is a thing of the past. I refelected on how many reports I’ve had of burned down unattended engines due to bad pumps, bad belts, or frozen tension idlers. I thought about my totally trouble free system at Easton. It brought a smile to my face.

Perhaps few of us think in terms of 6000 hours being equal to 100,000 or so of driving, belts, tensioners, and pumps do fail. If you have these parts, make sure you have an over temp shut down, Murphy is always there to bite you in the ass.


The Lister CS was designed to thermal siphon, but you do need a place to carry off the heat, and it need be adequate to work right.


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6 Responses to Kiss is Dead? Thermosiphon Cooling

  1. Elden says:

    I’ve also chosen to thermosiphon my Lister at the cabin at 9000 ft. Unfortunately typical 50/50 mixes of antifreeze boil at 212 degrees at this altititude, and I’ve always wondered if boiling occured near the exhaust seats. I’ve gone to a waterless coolant that boils at 370 degrees, and going waterless eliminates electrolysis and cavitation erosion.
    The radiator is from an Excursion and it’s mounted at a 45 degree angle to get some air moving via convection. This summer I’ll try it on the 12/2 to see if it can handle the load. One caveat, the coolant is viscous, about a 10 weight, and it’s difficult to get it moving. I’ve yet to take temperatures near the output of the head, but at least I’m not boiling.

    • George B. says:

      Elden, there’s no reason you can’t go to a pressurized thermosiphon system.. most of us run a little lower on the hill than you do 🙂

      I do like tank cooling, and making a friendship where they change antifreeze gives you a place to get lots of used stuff, just add a rust inhibitor..

      BUT… you can’t beat you present solution, that stuff is cool!

      so I think..if it isn;t in the design, it doesn’t break..

      • Elden says:

        I must admit I wanted to see if I could design a system with waterless coolant that no one else has tried. I suspect you understand the obsessive compulsive nature that drives such curiosity!
        As you know power is severely compromised at this altititude and while turbocharging is one obvious solution it’s not kiss IMO. I’m looking to use perhaps a 205 degree thermostat to get earlier combustion and increase torque without boiling the coolant.
        Given my goals, I’m also concered about blowing the “o” ring and dumping coolant into the crankcase, rendering a worthless, but expensive mix of synthetic oil and waterless coolant.

  2. Tracy says:

    I have tank cooling on my Listeroid, but I have returned to hopper cooling on my latest Chinese S195. It came equipped with a radiator, so I built my own hopper for it and run rainwater in it. The hopper not only has no moving nor wearing parts; it also has no hoses (unlike tank cooling) which can be another failure point. The pure water holds the engine temperature at 212 degrees F (plus or minus for altitude), which is an efficient temperature for a diesel engine.
    I use a one-gallon tank as a fail-safe; it forces me to visit the engine every few hours to refuel. While I am there, I check the coolant level.
    When freezing temperatures are possible, I drain the hopper. If I need to start the engine in freezing temperatures, I can heat a couple of gallons of water on a propane stove or wood fire, then pour it into the hopper. This preheats the engine and makes it easier to start.

  3. i got a cs 5/1- 2.5kva generating plant intending to set up a combined heat and power source off grid and wish to incorperate more modern solutions to certain aspects a thermostat being one of them. your site is interesting. i am still researching the situation.

    • George B. says:

      I consider the thermostat a must have item, I use a 190F thermostat, and have had success with it. It’s all too easy to make or modify the upper cooling flange to receive a thermostat. There are people who worry about thermal shock, and write of a necessity for a more complicated cooling system, but I have found a simple loop with cooling tank or radiator higher than the engine’s water jacket to work well. If you set up a a low pressure source of water to the lower inlet, and a thermostat at the top, you’ll soon learn what a small amount of water flow you need to cool the Lister at full load. Delivering a thermal shock to a massive piece of cast iron like this, that will take some doing, but others write about their fear. Running an engine at lower temperatures wastes fuel and creates additional wear and other problems that can be observed or measured over time. Designing a good themal siphon system is easy, and there’s no pump or belt to fail. Others will find a reason to add complexity, but we do so knowing there’s a longer list of things that can go wrong and often do WHEN you run long hours unattended. As for making use of the waste heat, an active circ pump can be added, take water from the top of the cooling tank (hottest), and transfer it to a point of use, and return it. The thermostat assures you don’t rob the engine of heat it needs to run safely and efficiently, and of course.. if the circ pump fails, you cooling system continues to work.

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