Author Topic: THERMOSTAT BLEED HOLE SIZE ?  (Read 18570 times)

NoSpark

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #15 on: March 21, 2009, 11:21:41 AM »
Not sure wher Stan gets his 'bimetal sping thermostats' from - mine have been wax operated for as long as I remember, and I am old.

We saved that one just for you RAB. LOL

Not one has adressed/mentioned the other possible problem of a faster warm up.  Reduce the water volume to the minimum required and the heat required will be at the minimum.  If yours is way oversized with metres of extra tubing that might be a much better place to start.

My system might contain 3 gallons of coolant, a far cry from say a 55 gallon barrel, its just to damn cold. When everything is warmed up I get a nice constant flow of warm air from the radiator. Once the inside of my garage hits 80f I'll be trying to get the thing to run cooler.

This summer I plan on cooling my house in the evenings with WVO. This will help me get the kinks out to run it more seriously next winter.
Anand Powerline 6/1 ST5

ronmar

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #16 on: March 21, 2009, 11:25:39 PM »
Nospark
  If the radiator fan was running all the time, that was probably your biggest issue as far as warm up.  On a 6/1, anything much larger than a metro rad is overkill, so in 20F air, even a little airflow can dissipate way more than the 17KBTU/hr that the engine can put into the cooling system at full load.  Basically, like hooking it up to a swimming pool sized cooling tank, you gave it a nearly inexhaustable supply of very cold water from the bottom of the radiator.  You could also run into this situation with a metro radiator and a good flow of 20F air.  The 180F thermo probably is still cycling also, but with the slightly lower opening temp and a bleed hole to allow constant flow, I am sure the swings are not as extreme.  Big semi trucks also run into this problem in winter.  They have a simple solution.  They put a cloth cover over the radiator inlet with a zipper on it to block a great deal of the airflow from the front of the radiator.  They unzip this cover as neded to control the airflow and match the radiators cooling ability to the engine output.

Personally I would put the 195 thermostat back in with an even larger bleed hole.  I bet it will work just as well in dealing with the swings as the 180 has.  The biggest fix though will be to get that fan control working so the fan dosn't run untill the system is warm, and can shut off so it dosn't remove too much heat from the coolant. The thermal switch controlling the fan can also give you an idea of how well the cooling capacity is matched to the heat load.  If the fan switches on and off at a fairly fast rate, it is moving too much air and overcooling the rad which causes the short cycling.  If it comes on and stays on all the time, it is probably not moving quite enough air.  Observing the fan cycling as well as the temps around the system will help you to match the cooling system to the engine.  IMO, ideally, you would want the fan to just stay on all the time at maximum load, and occasionally cycle off, say staying on 90% of the time at lesser loads.  In winter, use something to block airflow thru the radiator to maintain theis same relationship in the much cooler air.  Your goal is to be able to remove enough heat that the cooling capacity is within the thermostats ability to control without fully opening or fully closing.    You might find a much smaller fan or two, such as a 4" computer case box fan setting on the radiator face, can move enough air to maintain control.   

Another good reason for the 195 thermostat is combustion efficiency.  That 180F thrmo limits the upper operating temp.  I noticed a significant difference between a warm engine and a cooler one during my fuel consumption testing.  It does make a difference in how much fuel you will burn, and hotter(below boiling) is better IMO.  This may also make a difference when running alternative fuels as it will probably cut down on carbon buildup from the heavier oils.

Good luck.   
« Last Edit: March 22, 2009, 01:38:46 AM by ronmar »
PS 6/1 - ST-5.

Stan

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #17 on: March 22, 2009, 12:26:02 AM »
Jens, if you put 2 thermostats on with the heat sensor portion poking into the block, before the manifold, it would work much better.  I didn't realize you twin guys were putting the thermostat way up there a good 6 or 8 inches away from the block.  When the themostat is poking into the block itself, it heats up right away!
Stan

NoSpark

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #18 on: March 23, 2009, 01:23:36 AM »
Ronmar

        I think the radiator setup I have right now is almost perfect, the radiator isn't much bigger than a metro radiator but a lot smaller than the big heavy duty truck radiator I had before. I currently plug the fan in after the temp gauge stops swinging, Ive got to get that switch hooked up. The 195 thermostat may have been defective, because it allowed the coolant to go over 200 before opening. I'm not sure if I'll try another 195 stat or not, the temp control is so much better now. Today I started it at 50f and it warmed up pretty fast so thing are going to change.
Anand Powerline 6/1 ST5

ronmar

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #19 on: March 23, 2009, 11:58:58 PM »
The difference between the two thermostats was probably the bleed hole you put on the second.  It allowed the heat to reach the thermostat sooner, allowing it to open befor the temp peaked so high.  Even so, 200+F isn't really a problem as long as it isn't boiling at any point.  I think you will see some better performance if you partially block the airflow thru the rad when it is really cold. and of course get that switch hooked up:)
PS 6/1 - ST-5.

NoSpark

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #20 on: March 24, 2009, 05:11:59 AM »
The difference between the two thermostats was probably the bleed hole you put on the second.  It allowed the heat to reach the thermostat sooner, allowing it to open befor the temp peaked so high.  Even so, 200+F isn't really a problem as long as it isn't boiling at any point.  I think you will see some better performance if you partially block the airflow thru the rad when it is really cold. and of course get that switch hooked up:)

My temp gauge is after the thermostat, so if it was reading 200+ before the thermostat opened something was wrong. Now under a steady load she holds 180. In the old thermostat I had ground the original bleed notch in the valve bigger, this one I drilled. That could of had something to do with it. My biggest concern was not really the running temp but how long it took to get the return hose warm. I would rather have a 195.
Anand Powerline 6/1 ST5

Ratman

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #21 on: March 24, 2009, 07:40:37 PM »
A thermostat with a bleed hole usually has a pin and ball, this is to allow air to escape during system fill but to prevent hot water bleeding away to the radiator during warm up. The most common cause of temperature surge is too large a volume of coolant. Modern car engines produce masses of heat but only have a few pints of coolant.
I’m not yet a CS owner but I will be one day, my intention is not to use a thermostat at all, but a restrictor, this being just a plate in place of a thermostat, and experiment with hole size until the ideal temperature is achieved.
It might work, it might not. :)
Rob
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Ratman

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #22 on: March 24, 2009, 09:36:21 PM »
my intention is not to use a thermostat at all, but a restrictor, this being just a plate in place of a thermostat, and experiment with hole size until the ideal temperature is achieved.
It might work, it might not. :)

Rob, no need to re-invent the wheel. A thermostat is a tried and proven system to keep the coolant at a constant temperature. If you are REALLY concerned about heating the engine up quickly then put in a bypass system where coolant is circulated only through the engine until the thermostat opens. Even if you run into a thermal cycling issue from cold water entering it will stabilize itself quickly. Your restrictor method is bound to fail in many ways. There will only be one temperature point when all is well. The cold start and cycling might be bad and you might have it for 15 minutes or more but then you will stabilize. I fixed hole will over cool when the engine is cold and undercool when the engine is hot - it will never be stable.

Jens

But did Lister use a thermostat???????
I like to think the older I get the wiser I become, but I'm not so sure.

oliver90owner

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #23 on: March 24, 2009, 10:08:44 PM »
Did anyone use a thermostat in the 1920s?

Regards, RAB

Stan

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #24 on: March 24, 2009, 10:29:05 PM »
The Dursley Lister recommended a valve in the hot line that could be almost closed when starteup occured, and then gradually opened to maintain a heated condition.  This, however requires constant monitoring, and failure to monitor correctly could lead to an over heated condition.  They did eventually (don't know when, maybe Peter could shed light on this date?) start mentioning a thermostat in the line.
Stan

Wizard

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #25 on: March 24, 2009, 11:01:48 PM »
Was in all of this cases the radiator fan was running all the time?

Then, get the fan on the termostat switch.   Vehicles with electric fans didn't run at all till temp is reached then is switched on.

Small hole in the thermostat is good especially for lister to have little of heated water trickling into the cold side of cooling system.

Cheers, Wizard

compig

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #26 on: March 24, 2009, 11:21:41 PM »
Thermostats are listed in a 1940's parts list that I have. It appears to be an in line hose mounted type.
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Stan

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #27 on: March 25, 2009, 12:37:14 AM »
My research shows they were first mentioned in the radiator models.  It would make sense!  The tank models were easier to control heatwise, with the much larger volume of liquid.  45 gal in temperate climates, double that in the tropics.
Stan

oliver90owner

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #28 on: March 25, 2009, 07:36:39 AM »
compig

Thermostats are listed in a 1940's parts list that I have.

With respect, that COULD be thirty years later.

One of my tractors came without a 'stat in 1948 but was soon field modded to use one (I have both water distribution maniflods for the tractor). 

The point was: were there thermostats in the 1920s (or before)?  Were probably bi-metallic strip ones if there were. :)

Your 1940s list might be 1940 or even late '49.  A great deal of technology advancement went on over such a long period.  Like pneumatic tyres being one development which advanced sufficiently to alter the direction/rate of agriculture.

The switched electric fan is now almost universal on smaller motor vehicles as it is the most efficient option available.

Regards, RAB

compig

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Re: THERMOSTAT BLEED HOLE SIZE ?
« Reply #29 on: March 25, 2009, 09:10:28 AM »
It's a 1948 publication and the thermostat is listed in the water tank & fittings section. There are two sizes , for 1-1/4" hose and 1-5/8" hose.
DON'T STEAL , THE GOVERNMENT DOESN'T LIKE COMPETITION !!!
Lister A
Onan W3S Genny
Petter A1
Villiers C45 industrial
Continental flat six powerpacket
ANOTHER Lister 6/1 CS SOM , temporarily !!!