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Author Topic: Thermostat needed (?) for 3.5 HP Petter  (Read 10175 times)

edutchie

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Thermostat needed (?) for 3.5 HP Petter
« on: June 14, 2006, 09:52:04 PM »
I am working with mkdutchman, trying to unsmoke a mini-petter. (see post by mkdutchman)
Some say we need a thermostat, some say thermosiphon takes care of itself.
What have you experiences been?
What type of thermostat are you using and where can I get one?

GuyFawkes

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #1 on: June 14, 2006, 10:27:00 PM »
Thermosyphon is a lot more efficient than people realise, even at low temperature differentials, but I suspect a lot of the problem is people running these engines at very low rack openings, if you don't have much of a load, create one, fuel consumption is economical enough, so treat it as "free" work and beat yourself up for not using it, even if it is running a bar fire in the open air to dry the soil.

once you accept that first Kw is free energy going to waste, there are a hell of a lot of things you can do with it.
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Original Lister CS 6/1 Start-o-matic 2.5 Kw (radiator conversion)
3Kw 130 VDC Dynamo to be added. (compressor + hyd pump)
Original Lister D, megasquirt multifuel project, compressor and truck alternator.
Current status - project / standby, Fuel, good old pump diesel.

Andre Blanchard

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #2 on: June 14, 2006, 11:26:52 PM »
Thermosyphon is a lot more efficient than people realise, even at low temperature differentials, but I suspect a lot of the problem is people running these engines at very low rack openings, if you don't have much of a load, create one, fuel consumption is economical enough, so treat it as "free" work and beat yourself up for not using it, even if it is running a bar fire in the open air to dry the soil.

once you accept that first Kw is free energy going to waste, there are a hell of a lot of things you can do with it.

Yep, that's why some put in a thermostat, to slow down the circulation a bit.

I just thought of something, rather then just baking dirt :) a good use for waste heat would be a wood drying kiln.  Kind of a symbiotic relationship the kiln needs a lot of heat and just enough electricity for the controls and fans, and we all know the engine makes a bunch of heat and some electricity.  If you run your engine 24/7 you could dry lumber and likely make more then enough money to pay for your fuel.  If your engine is just run now and then I would look at drying fire wood, controlled drying of quality lumber is not a process that can be started and stopped at random but fire wood does not matter.  And well dried wood makes for a lot better fire when it gets really cold.
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GuyFawkes

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #3 on: June 14, 2006, 11:40:48 PM »
if you have land and a little space between you and neighbours then there's lots of money making things you can do with "free" power, electroplating, anodising, induction furnaces.....
--
Original Lister CS 6/1 Start-o-matic 2.5 Kw (radiator conversion)
3Kw 130 VDC Dynamo to be added. (compressor + hyd pump)
Original Lister D, megasquirt multifuel project, compressor and truck alternator.
Current status - project / standby, Fuel, good old pump diesel.

mobile_bob

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #4 on: June 15, 2006, 03:21:06 AM »
i would like to state that thermo syphoning can take place with as little as one degree of temperature differential.

so without a thermostat and useing a water tank that is not closely matched to the exact load, ambient temperature(which would have to be constant) there is no way to get the engine up to proper operating temp with any consistancy.

for instance

say a minipetter was put together with a thermosyphon system using a 5 gallon tank and carrying a 1.5 kwatt load on a 90 degree day(ambient) it might come up to around 190 degree's F.

now using the same system, and moving the ambient temp lower by 40 degree's, and reducing the load to .5 kwatt, the operating temp of the engine will fall below 190 degree's and likely far below 190.

the tstat control would maintain the temp up to 190 or so, reguardless of load or ambient temperature.

even modern designed diesel engine's will emit a haze or gray smoke when running in cold ambient temps and no tstat, especially at no or low load conditions.

also if you want the engine to live a long life you want it to run up to around 180 to 195 degree's.

other consideration are when running an engine at low temp's it is hard to get enough heat rise in the crankcase to boil off
condensation in the lube oil, causing acidity to build up and other problems that shorten engine life.

i have seen too many diesel engines that are poorly maintained, with either missing or failed tstats, stuck fan clutches or fan controlls worn out far too soon. and they all emit smoke!

i really don't know why a petter or a lister would be any different.
bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

Doug

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #5 on: June 15, 2006, 04:43:38 AM »
I've been picking over the corpes of my old "Mine Cat" ( New Holland tractor conversion for use in mines cylinder Ford, not the nicest way to get around but it beat walking ). Among the things I snatched were the Rad, thermostat and housing, all Ford parts. Nice big 3 core rad with lots of surface area that I hope won't need a fan. Nice big Ford thermostat housing that I hope I can make a short stand off adaptor for and use the original Petter cooling outlet with.
My thinking is to use the largest practical parts that will free flow well and close of well when cold. I could have just as easily used 520 Kubota parts, but I want bulky to blow off heat and Ford thats easily a stock item at any parts store.

Doug

Andre Blanchard

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #6 on: June 15, 2006, 01:07:49 PM »
if you have land and a little space between you and neighbours then there's lots of money making things you can do with "free" power, electroplating, anodising, induction furnaces.....

Yes, but those are all electric loads which could be used if your only goal is to increase the load on the engine to get it's temp. up.  The trick is to find something to do with all the heat, in cold weather it can be dumped into the house but what to do with it the rest of the year.
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Andre Blanchard

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #7 on: June 15, 2006, 01:12:18 PM »
i would like to state that thermo syphoning can take place with as little as one degree of temperature differential.

It will take place with a lot less then one degree differential, if the water is completely homogenous (no salinity concentrations etc.) ANY temp. differential will get things moving. :)
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fattywagonman

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #8 on: June 15, 2006, 02:43:45 PM »
See guys, If you are using thermo siphon ... the trick is to run the engine low on water that way the water must boil to circulate :)

solarguy

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #9 on: June 15, 2006, 04:33:38 PM »
I originally set up my 6-1 w/o a thermostat, with thermosyphon.  Took more than an hour to make it to operating temps, even with a good 2.5kw load.

Then installed t-stat a couple of weeks later, what a difference.  Up to 190F in ten minutes every time, regardless of load.

Finest regards,

troy

ronsmith

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #10 on: June 15, 2006, 05:29:33 PM »
How can you adapt a thermpstat to the hot water side on a mimipetter? I tried to put in a 190deg. stat in line near motor and ran for 20min. or so and the motor got hotter than hell but stat never opened so I removed it. It also smoked during the whole time. I made sure the stat was installed facing the proper end. Can someone tell me how to adapt stat directly to petter block? :-\

Andre Blanchard

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #11 on: June 15, 2006, 05:56:01 PM »
How can you adapt a thermpstat to the hot water side on a mimipetter? I tried to put in a 190deg. stat in line near motor and ran for 20min. or so and the motor got hotter than hell but stat never opened so I removed it. It also smoked during the whole time. I made sure the stat was installed facing the proper end. Can someone tell me how to adapt stat directly to petter block? :-\

I short while back Guy posted a pic of a remote thermostat housing, you will note it had three ports.  One in from the hot end of the engine and two outs, one of the outs is blocked by the thermostat and should go to the cooling system the other out goes back down to the cold end of the engine.  That allows a circulation path for a small amount of water between the engine and the thermostat housing, when that water gets hot enough the thermostat starts to open and a second circulation path starts thru the cooling system.  Without that first circulation path the thermostat will never get to see the hot water in the engine, even if it is just a short hose because contrary to popular believe water is not a very good CONDUCTOR of heat it is good at moving heat by convection (thermo siphon) but by conduction it is better then air but not near as good as say iron.

A second way, but not as good in my opinion, is to have a small leak thru the thermostat so that the hot water can get to it.


On conduction of heat by water.  One common problem with the boilers on traction engines running in very cold weather is that the water under the fire box would freeze solid even while it was making great volumes of 150 psi steam.  This would happen because the circulation in that part of the boiler tends to be very slow.

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ronsmith

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #12 on: June 16, 2006, 07:50:19 PM »
I looked up Guys thermostat housings and they look like what I need. I wonder how to go about buying one? ???

Andre Blanchard

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #13 on: June 16, 2006, 08:15:27 PM »
I did a bit of searching and mostly found that cars using them had names like BMW, Porsche, and Ferrari.  Not many of them in junkyards around here.:)  A Ferrari rolled thru town one time, looked like a dam parade with people following, pointing and stuff.

They must be available but I did not find any, but I did not do much of a search.
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GuyFawkes

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Re: Thermostat needed (?) for 3.5 HP Petter
« Reply #14 on: June 23, 2006, 05:58:54 PM »
I did a bit of searching and mostly found that cars using them had names like BMW, Porsche, and Ferrari.  Not many of them in junkyards around here.:)  A Ferrari rolled thru town one time, looked like a dam parade with people following, pointing and stuff.

They must be available but I did not find any, but I did not do much of a search.


very very common on modern watercooled japanese motorcycles.
--
Original Lister CS 6/1 Start-o-matic 2.5 Kw (radiator conversion)
3Kw 130 VDC Dynamo to be added. (compressor + hyd pump)
Original Lister D, megasquirt multifuel project, compressor and truck alternator.
Current status - project / standby, Fuel, good old pump diesel.