Thermosiphon Cooling

| June/July 2003


The following comes from a recent topicon SmokStak, which can befoundon the Internet at: smokstak.cgi.

I'm using a screen-cooling tank on a 17 HP Ruston engine, running slow and not under load. I tried a belted pump, but the engine would not warm up. I have the bottom of the tank higher than the water level in the block of the engine. After it comes out of the engine, the water has to go up about 38 inches to the screen.

Is 38 inches too much of a rise from the top of the cylinder to flow to the screen-cooling tank? - Terry

To thermosiphon, the top pipe must be below the water level to make a complete loop. A screen-cooled tank won't allow thermosiphoning. Could you install a valve before the pump to throttle the flow? - Bill

You can use any kind of tank for your cooling system, and if you use a pump you can certainly use a screen cooler. If you do not use a pump you have a thermosiphon system and the water will circulate by convection as it gets warm. If you want a screen cooler you must use a pump - thermosiphon will not 'pump' water up to a screen. You mentioned you used a pump and your engine didn't get warm. You were circulating water from your cooling tank and the engine had to heat up all that water. I had a 15 HP Reid and it would run for four or five hours before it would heat all of the 40 gallons in my tank. Give it time! - Norm

Aren't some screen-cooled Moguls thermosiphons, yet they have a screen tank? The water barely trickles out if you run them slow, but until the engine is pretty warm nothing comes out! - Laura