Will this thermosiphon?

[cognos]

Sooo... shut off the pump, and test the theory while you're right there to monitor it, and everything has stabilised.

Troublemaker.

Casey

Oh ya. 

Well, that's what I'd do...

[bschwartz]

195 degree thermostat, and temperature controlled fan. 

Sooooooo..... I unplugged the pump.
Temp climbed up to around 205 and the fan turned on. BUT.....
By the time the fan kicked on, too much coolant was boiling out into the overflow tank.  I turned the pump on and it did circulate, and cool down everything and suck the overflow back into the system.
It might run OK if the fan had been kept on full time.  Otherwise it was just too late to play catchup.

Next test will to try the fan on full time and unplug the pump and see.

Maybe next weekend when I have more time to play.


Next week......
Same Bat time......
Same Bat channel......

[LowGear]

Playing is good.

Casey

[bschwartz]

Damn I'm impatient........

So, I started with the fan on.
The engine came up to 200, dropped to 170 when the thermostat opened.
Climbed back to 200, dropped to 175 when the thermostat opened......
Did this till it stablized at about 195 (the thermostat temp).

Thermosiphon works with the pump inline, and a 2300 watt load on the ST-5.

Now I can try to figure out a high temp switch which could turn on the pump for extra flow if it gets too hot.

I'm a happy camper with this setup. 


Thanks for the feedback guys.

[cognos]

That's great! Redundant system with no-power fail-safe failure mode! Best case scenario.

[bschwartz]

I wish it were a no-power fail-safe system.

It needs power for the radiator fan (120v ac), and in an overheat situation, it needs 120v ac to turn on the circulating pump.

If the ST-5 were to quit while the engine was running, I am pretty sure it would overheat with no electricity for the fan, or pump
.......... then again, with no load, I don't know what it would do

............... time for another test.

[XYZER]

Temp climbed up to around 205 and the fan turned on. BUT.....
By the time the fan kicked on, too much coolant was boiling out into the overflow tank.  I turned the pump on and it did circulate, and cool down everything and suck the overflow back into the system.
It might run OK if the fan had been kept on full time.  Otherwise it was just too late to play catchup.

Next test will to try the fan on full time and unplug the pump and see.

Was it expanding or boiling.....nothing wrong with expansion....a fact of life. I call it an expansion tank....

The engine came up to 200, dropped to 170 when the thermostat opened.
Climbed back to 200, dropped to 175 when the thermostat opened......
Did this till it stablized at about 195 (the thermostat temp).

Put a slightly bigger bleed hole in your thermostat and it will climb steadly without the cold dump on a warm engine. It will also allow flow if you did have a stat stick....

[bschwartz]

Was it expanding or boiling.....nothing wrong with expansion....a fact of life. I call it an expansion tank....


It was filling the expansion tank FAST and there were bubbles in the line...... I think boiling


The engine came up to 200, dropped to 170 when the thermostat opened.
Climbed back to 200, dropped to 175 when the thermostat opened......
Did this till it stablized at about 195 (the thermostat temp).


Put a slightly bigger bleed hole in your thermostat and it will climb steadly without the cold dump on a warm engine. It will also allow flow if you did have a stat stick....


The next time I drain the system, I'll add another bleed hole.  Thanks for the suggestion.

[Horsepoor]

I've been using these Grundfos circulating pumps on both my listeroids with no problems, as have two of my neighbors. If you shop, you can buy them at $68 per unit.

http://www.buyplumbing.net/?pg=pd&_i=UP1542F

I set them at the lowest seting, 3 gpm, and forget about it. As for the radiator, check Surplus Center for a 230 V fan. Draws 0.4 amp and you could just let it run or have it switch on and off with a thermal sensor switch.

https://www.surpluscenter.com/home.asp?UID=2009052819530308
https://www.surpluscenter.com/item.asp?item=16-958-A&catname=

[cognos]

I wish it were a no-power fail-safe system.

It needs power for the radiator fan (120v ac), and in an overheat situation, it needs 120v ac to turn on the circulating pump.

If the ST-5 were to quit while the engine was running, I am pretty sure it would overheat with no electricity for the fan, or pump
.......... then again, with no load, I don't know what it would do

............... time for another test.

Ah, I missed that part. Must improve my retention skills...

[Ronmar]

The only thing I would say is to put the heatex vertical right above the radiator inlet.  To enhance thermosiphon flow, you want all the heat input going up on one side(cylinder and head).  You want all your cooling going down on the opposite side of the highest point in the system.  Putting the heatex horizontal at the top might actually stop the flow when you try and transfer heat out at that point.  If the plumbing apexed just before the heatex, and then flowed down thru the heatex to the radiator, that added mass of dense fluid created when you draw heat from the heatex would actually enhance the flow...

Small plumbing is not especially a problem, as it dosn't take much flow to move the het from a 6HP engine.  The problem is that the drag it creates really works against thermosiphon as there is so little energy available to pump the coolant. 

Oh, new thermostat right?  If you have a weep hole already, run it a bit, as i have found new thermostats sometimes a little bit "sticky", and will loosen up, and open easier with a little use and some heat cycles under their belts...   

[XYZER]

Oh, new thermostat right?  If you have a weep hole already, run it a bit, as i have found new thermostats sometimes a little bit "sticky", and will loosen up, and open easier with a little use and some heat cycles under their belts...   

Mine never improved. If you had a pump and a bypass it would rise steadily. The thermostat will not open until it hits it rated temperature. Then it closes when the cold coolant hits it and repeats the cycle until it is at operating temperature. The "correct" size hole will allow enough circulation to prevent the thermostat from opening until it reaches its rated opening temperature........That's my experience anyway. ....

[bschwartz]

Although nothing is impossible, you may see from this picture some of the difficulties in turning the heat exchanger on end, and moving other things around.  The HE is about 4" below the garage door. 
Go ahead and laugh at my mess 

[bschwartz]

And for you observant people...... Yes it is fun shooting a game of cricket when the engine is running 

[deeiche]

rm /