Author Topic: utterpower changfa cooling conversion plate specifics  (Read 602 times)

Boxelder

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utterpower changfa cooling conversion plate specifics
« on: August 04, 2018, 01:06:31 PM »
Planning on converting the Changfa 1115 to radiator thermosiphon cooling.  George's plate seems to have the thermostat on what I'd consider to be the proper place for the "cool" inlet return line closer to the crankshaft, farther away from the head.  The port by the top of the cylinder would presumably be the "hot" side outlet.  Also, there should apparently be a tube extending down into the jacket a few inches on the return line?

Can someone please talk me through the physics and thinking about these conversion plates?  My understanding is that the cool return line should drop in via that extension tube closer to the crankshaft, and the outlet should be near the top of the cylinder, with no extension tube.  Correct?

Also, I've been looking everywhere for a copy of the utterpower CD, but there's no link to buy them anymore.  Can anyone tell me where I can find one?  I'd love to see what's on it.

Thanks in advance for all advice.

mikenash

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Re: utterpower changfa cooling conversion plate specifics
« Reply #1 on: August 05, 2018, 10:26:03 AM »
People will have better-informed opinions than mine - but I'm not sure that thermosiphon and thermostat are a good combination?

There are "basics" to good thermosiphon layout:

Both pipes should  ideally have a slight upward rise from heat source to storage/cooling

Neither pipe should have a dip in it

The system needs to be vented to atmosphere not pressurised - I believe

The top pipe needs to be discharging into water not into air above water - I think

I would guess that at the engine end the thermosiphon would work best if, ideally, the bottom of the bottom pipe and the bottom of the cooling jacket were level - or close too - so that there's no "dead" water not circulating at the bottom?  Equally, if the top of the top hose was contiguous with the top of the cooling jacket to that there wasn't a pool of hot water at the top not going anywhere - I would think that was ideal?

Those thoughts are based on having built several woodstove wetback systems to thermosiphon into hot water cylinders - I am just assuming that the physics are the same . . .

And we know what they say about assumptions  :)

Boxelder

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Re: utterpower changfa cooling conversion plate specifics
« Reply #2 on: August 05, 2018, 12:42:30 PM »
Thanks for the suggestions.  I'll pass along my thinking to the class and see what I'm missing.

Starting with the temperatures on the head, my inclination is to believe that the hottest part of the cylinder would be right at the top where the compression is highest and the burning fuel most intense.  Since heat rises, the hottest part should be the top of the cylinder referential to gravity.

The coolest part of the cylinder should be down at the bottom of the cylinder, underneath the cylinder referential to gravity.  I believe this is why there's the additional nipple on the return line, to get the coolest water back to the coolest spot on the cylinder.  From there it would circulate, do its thing, and eventually recycle back up the "hot" outlet.  There would be no need for a nipple on the exit, since you'd want the hottest water at the top of the jacket to be what exits.

Regarding the thermostat:  Since these engines are designed to be cooled by boiling water, one must assume the optimum working temperature is 212F, 100C.  It'd decrease slightly as altitude increases, but power would also decrease.  The utterpower site recommends a thermostat set at 192F.  I understand the thinking behind it, as it would allow rapid warmup of the engine, and accurate temperature control after warmup.  This should increase efficiency a bit, not that it's my first concern.  What is concerning is that without the thermostat, it'd take quite a while indeed to warm up 55 gallons of water to reasonably high operating temperature.  This means the engine would be running for an extended period of time at a cooler temperature than it was designed to, each time it's fired up.

The thermosiphon cycle:  There would have to be a continuous loop of water, with no downhill portions of the loop.  Whether it's pressurized or not shouldn't matter much as long as the entire loop is pressurized to the same PSI.  But it shouldn't be necessary, and in fact it's something to be avoided when using a 55 gallon drum setup.  Shouldn't be a problem with the 192F thermostat.

The thermostat:  It will surely impede flow a bit, acting as a resistor in the system.  But I bet there'll still be enough flow to be effective, or George's cooling plates would have been redesigned and built without them after a few folks warped their heads.

I plan on using this engine/genset to power my shop, as the local power company charges me $55 every month base rate, and then commercial rates on top of that.  Even though it's on a residential property, their blanket policy is that a second service line is automatically commercial.  Dirty rats.  Since I don't spend that much time down there what with the new addition to the household and all, I figure I can make my own juice and save a few bucks.

Really it's an excuse to play with awesome toys, is what it comes down to.  At least I'm honest with myself.


mikenash

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Re: utterpower changfa cooling conversion plate specifics
« Reply #3 on: August 06, 2018, 02:17:32 AM »
Right

I had thought when you said "radiator" you were talking about quite a small volume . . .

But now we're talking about 200-litre drums I guess that's another story

FWIW our experience here with old Listers was that they were started in the morning and ran for ten or twelve or fourteen hours, mostly under load, as shearing-shed plants.  So, even if they ran cold for a bit, they had plenty of "hot" running to follow that

I guess the thermostat kind of strikes me as adding a potential point of failure into something that would otherwise have no moving parts and was close to "idiot-proof"  That's not sound thinking on my part, just a bit of luddite-ery

Boxelder

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Re: utterpower changfa cooling conversion plate specifics
« Reply #4 on: August 06, 2018, 10:35:15 AM »
Yeah I did say that. It was misleading. I apologize.

I haven't really made the decision yet whether to use a tank or a radiator. Just trying to get all my ducks in a row with my understanding of the system.

EdDee

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Re: utterpower changfa cooling conversion plate specifics
« Reply #5 on: August 06, 2018, 10:52:07 AM »
Hey BE,

I have two setups - One with radiator which has heat exchangers on the cooling side as well as on the exhaust side to reclaim the heat for heating water.... This works very, very well, with all sorts of dangly bits to turn on fans for cooling the radiator and keeping things at the right temperature engine wise...

The other simply has a 200L drum with hydronic circulation for both the engine as well as the exhaust heat exchangers... Nothing fancy at all.... It gets up to temperature slower, but hits the 90C mark and stays there, regardless of the weather conditions...

As to which is best? Probably the drum cooled one, a bit luddite, granted, but way simpler and easier to manage...

Best performance? Equal

Reliability? Drum

Fun? Radiator

Versatility of fuel? Radiator

Impressiveness? Radiator

More prone to failure? Radiator

and so the list goes on.... But, if I build yet another one.... Drum!

Cheers
Ed
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38ac

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Re: utterpower changfa cooling conversion plate specifics
« Reply #6 on: August 06, 2018, 12:43:25 PM »
- "but I'm not sure that thermosiphon and thermostat are a good combination? "  I agree but others differ.

An upright engine that was designed to be thermosypon cooled such as a CS or clone is a different cat than one that was not (the horizontal Chinese). While the basic principles do not change operation in the field is very much different due to how the coolant flows through the horizontal engines using a plate. If you were to bore and thread a large hole under the cylinder on your engine then standard Listeroid practice could mostly be applied.  The coolant will barely flow in a plate equipped engine until the engine is hot anyway.  The plate should be set up with the ports diagonal in opposite corners. the one closest to the head will be the hot outlet and the one closest to the crankshaft will be the return. The system will run best of you run the return pipe past the plate into the water jacket a ways. What this prevents is confusion as to which way it wants to flow when first started up. Without it depending on you exact set up it will often try to flow backwards which results in no flow and overheating.  I have found that the horizontals using a radiator very much self regulate without the 'stat and none I have built (4) use them or need them, others report different.  Having helped several with system issues the most common mistakes are thinking that hot coolant is somehow going to flow downhill, or in turn that the cooled return is some how going to flow up hill, neither is going to work. The other big mistake is using radiators not designed for thermosypon use. You MUST be sure that the top hose remains submerged in coolant at all times. If using a radiator with a small top tank that means you must add a reservoir above the radiator to insure it is full at all times OR use a radiator designed for such that has a large area above the hose built into the top tank.  As sure as I say that you must use a vertical flow radiator somebody will chime in that they found a way to make a horizontal flow work so let me say it this way. Save yourself head aches and use a vertical flow radiator.

I prefer to control the engine temps on my plate conversions with a fan switch. The ones I use  turn the fan on at 200 and off at 180 and unless under very high loading and hot temps they cycle on and off (mostly off) to control the engine temp nicely.  It takes my 1115 and average f 15 minutes to get warm enough to turn the fans on. As a test I pinched off the top hose so no coolant could flow and it took 10 minutes to get hot enough to turn the fans on, why run a 'stat??
I can take a few pics of my 1115/15KW stand by set if you have interest.
« Last Edit: August 06, 2018, 12:52:17 PM by 38ac »
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38ac

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Re: utterpower changfa cooling conversion plate specifics
« Reply #7 on: August 06, 2018, 12:57:28 PM »
Should have added do not cheapskate the material for the plate.  I consider 1/2" plate to be the minimum due to the distance between the bolt holes. My very first plate was 3/8" and did not work due to constant leaks.
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glort

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Re: utterpower changfa cooling conversion plate specifics
« Reply #8 on: August 06, 2018, 01:49:52 PM »

I have to say, I think this is another case of western mentality overthinking things.

There are millions of these engines literally all over asia slogging away day in, day out for years at a time and probably using buffalo pee or rice paddy water  for coolant. many have a radiator, many have nothing more than a water bath. They go and go and the people running them probably never change the oil, only top it up with oil out of a truck that they change every 5 years wether it  needs it or not.

 Westerners come along and get all pedantic about the temp the engines run and precise cooling, the grade of multi grade oil that 50C better than the machine needs and so it goes.  If engines were so damn temp finicky, there would be no such thing as an aircooled engine.  You can have them plodding along for hours on end happily and you can be thrashing the backside off them and they still, especially Diesels, last for decades.

In reality, with modern oils, all you really need to worry with a watercooled  IMHO is not overheating the thing too much.  If the thing is running at all and it's not sitting there doing nothing all day, It's probably warm enough.  I don't think a lot of the old wives tales are relevant any more like not running a diesel hard will clag it and an engine has to run at a certain hot temp all the time.
The way I see it, that is mainly oil and fuel related and with modern oils particularly and fuel, it's just not the concern it was 30 or 50 years ago which is the time frames a lot of these positions were formed in.


Another thing I find is really out of touch is the " Bullet proof" concept .  Can't have a radiator or a fan or anything else that might fail. It's a fallacy far as I'm concerned.  There will always be a radiator hose, a clamp, belt or just the build quality of the engine itself that is a failure point. Putting in a thermostat and then saying you don't want to use a radiator or fan makes no sense. The goddam thermostat is WAY more likely to fk up and cause a problem than a rad or a fan. I have had several problems with thermostats in cars over my life, Cannot remember one with a rad that wasn't physical damage and certainly not a fan.  the odds of them failing in stationary use is magnitudes less than in automotive use where they are subject to all sorts of Vibration. In any case, a radiator bursting in a non pressurised system as most would run rather than developing a small tell tale leak, is lottery winning odds.  If you use a tank, how often you going to check that? You going to put in gallons and gallons of expensive corrosion inhibitor in it because if not, then it can rust and leak or go brittle in the case of plastic.

EVERYTHING has weaknesses and failure points and making things " Simple" frequently makes them failure prone.

Trying to build out remotely modern ways of doing things is not logical because you can't. If one looks at commercial stationary engine use, you don't see a 500Kw V12 CAT gen set running a great big tank cooling unit because they are worried about the rad bursting. They incorporate a temp shutdown that we can buy off fleabay for $10 if you pay too much an apply to our own engines.  They also have inspection and maintence schedules.  Like oil, you don't wait till the engine throws a rd before changing the oil, you do it at a regular interval before it wears out and becomes unreliable.
Often all this over simplistic thinking just makes things more likley to suffer a failure as well as more bulky and cumbersome.


Fans and radiators seem to be real popular out of date thinking.  I look at automotive development and use.
A vehicle would have to be magnitudes more of a demanding  use than stationary duty.  Radiators in cars rarely fail anymore.  They get a stick or stone though them on occasion ( and even that's much more rare now due to design and the fact you have an AC condensor sitting in from of a lot of them but outright failure..... Just does not happy within a 1000th of the fearmongering that is levels at it.
Years ago wrecking yards and parts places did good business in radiators. Now the main times are accident damage or for 10+ and more like 20 yo vehicles.

Same as radiator fans. They just go forever. Even in 10 yo cars to replace a fan through other than physical damage is very rare.
I have an electric rad fan that I have run in a window of the house ( and now the garage) for the last 4-5 Summers, most of the time non stop.  It ran for about 8 Months when I came here off the solar panels on the shed roof. The thing was 15 Yo when I got it so had been spinning on a car all that time ( whether it was actually running or just coasting in the 100Kmh breeze) and its' still going. on the rare occasions they do go, they usually squeal like stuck pigs. They will work for many months many hours a day like that but I have yet to see one just ship itself and instantly fail.

As far as failure points go, your radiator hose is about 100X more likley to fail than the radiator or the fan on it.
For those of us who use our engines as toys, you'd never wear them out. For those that rely on them and use them every day, do it aircraft style. they don't try to use things that never fail, they work on redundancy and  time.  Get a new ( or low mileage/ late model ) fan and rad every year. they are cheap as chips now anyway so us scrooges have to get with the times and let the moths fly out out pockets now and then as well.

All this old school, great grandfather thinking hold us back. A lot. Thermostats are still far from bullet proof and then there is the risk of a tank corroding or cracking.
I always say that a lot of opinions take 30 years to change. Probably a lot more in this game.  I talk to people all the time that think Automatics in cars are failure prone and use too much petrol therefore they would never drive anything but  a manual.  I hear people say that fuel injection is unreliable and they are still driving cars with carbys and try to tell you " It's a good car". It's an old, outdated car that you would do well to update and get with the times. I often ask these people if they still have a B&W TV because those colour ones are trouble!   :laugh:

In my book, if it's good enough for a car, then worrying about things failing when they are just sitting there especially when there are other things a lot more likely to fail is Illogical.

In this case, I would go with a radiator and a fan and add some " Complication" as people love to call it in the form of shutdowns or alarms.  It's not complication, it's prevention.  Add to that regular inspection and maintence such as changing things like hoses and you are far less likely to have a problem with things DO fail as they always will than kidding yourself stick and stones will never, ever break.

/rant.


38ac

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Re: utterpower changfa cooling conversion plate specifics
« Reply #9 on: August 06, 2018, 04:20:06 PM »
Glort, we are in almost complete agreement.
My way of saying same things is this; Rocket science is needed to fly a rocket, it certainly isnt needed to properly operate an engine that was designed  prior to rockets. When simple works, why complicate it? Paying too much attention to what ifs will lead to over complication.
« Last Edit: August 06, 2018, 04:21:49 PM by 38ac »
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Boxelder

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Re: utterpower changfa cooling conversion plate specifics
« Reply #10 on: August 07, 2018, 11:22:00 AM »
Wow guys, thanks so much for the detailed responses!

The radiator without a thermostat in the line but with a thermostat in the radiator to control the fan seems like a great combination.  I'm going to try that first and see how it goes.  The tank idea is great if the setup is never going to move, but my plans are to have it be at least partially mobile.  It'd also be nice to have a closed system which could use antifreeze so I didn't have to drain it when it threatens a frost.

Making the plate should be easy enough, I have a Chinese Bridgeport clone and more lathes than I know what to do with.  Time to find a nice thick piece of stock.

I'll visit the local radiator shop and try and find a good top-bottom style setup.  I've seen quite a few videos on YouTube, including 38ac's 5kw setup so I know exactly what you're talking about.  I just wish I had the artistic touch he does for constructing the cart, that thing is excellent!

Thanks again, and I'll keep the group in the loop with what I come up with.

glort

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Re: utterpower changfa cooling conversion plate specifics
« Reply #11 on: August 07, 2018, 12:16:08 PM »

I'll visit the local radiator shop and try and find a good top-bottom style setup. 

On my roid I used a Subaru Cross flow Type Radiator..... and turned it sideways.  Worked Brilliantly.
I set it up as a non pressurised system and would do that again as well. Even if this engine is to be put on a trolley, all you need do is have a small tank at the highest point with a vented lid.  Maybe something like a vent tube on a bike fuel tank would be good to allow air but minimize coolant losses when moving the thing.

I had the thermo fans on the radiator but ran them through a tail light globe to slow them down. with the size of the rad being made for 150Hp engine, a gentle breeze blowing on the thing just moving air through it would be enough for the roid.  If you can get a smaller radiator at a workable price, that would be better for packaging considerations. Something off a Bike would be good but maybe exy. They are here, don't know about where you are at.

I would also look at a water pump for the thing.  You can get electric car waterpumps that take 3/4 or 1"  pipes which would be all you need and just put a PVC joiner in some radiator hose and screw a fitting in and clamp it to the smaller hose.  Positive water movement would be better for the engine to maintain a more even temp.  One thing to have evaporation cooling but them having to make the coolant travel through hoses I think will upset the design apple cart.  You could direct a pipe through the plate to the Crank for the inlet and another the opposite way to pick up fron the head end and maybe put a bit of a baffle in between to aid circulation.
 Plus with a pump and a controller, you have a kind of thermostat built into the engine anyway.

What is the engine going to be driving?  Generator?

38ac

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Re: utterpower changfa cooling conversion plate specifics
« Reply #12 on: August 07, 2018, 12:32:26 PM »
The radiator on the 8/1 on my youtube channel is the one I prefer to use. They come from John Deere LUC power units that are in abundance in the midwest, average cost $50 and they are designed for thermosyphon cooling. They are a bit large for a CS single cylinder engine but perfect for a twin or 195-1115.
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Boxelder

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Re: utterpower changfa cooling conversion plate specifics
« Reply #13 on: August 09, 2018, 01:32:56 AM »
Glort - the Changfa is already mounted to a 15kVa ST generator head via a Lovejoy style coupling.  This coupling is absolutely massive, and the whole shebang is bolted to an EXTREMELY sturdy double C-channel welded and reinforced frame.  The previous owner was using it for - get this - an electric car conversion which he raced in the 24 Hours of Lemons circuit.  This motor has actually set a record for the longest distance driven in 24 hours by an electrically powered homebrew car.  The problem was it weighs a half a ton, literally.  His 1980's P.O.S. just couldn't handle the weight.  So it was replaced by a Harbor Freight generator which isn't a quarter as stonkin' but happens to be a quarter of the weight.

For my purposes I'm going to be running it intermittently, perhaps two or three hours at a time maybe four days a week.  I'm trying to fire the power company, which is charging what I consider to be penalty rates for a home shop gamer just trying to enjoy his free time.  They're charging me $55 a month base rate, and then commercial usage rates on top of that.  If I can run this thing instead, I might actually make some money back on it - this would be a new experience for me.

38ac - I've done some searching online, and the cheapest LUC radiator I've found is listed at $200.  If you have one or two you're not using, I would definitely like to acquire them from you if you're interested in selling them.  There aren't so many down in Georgia as there are in the midwest.

The engine came with a bolt-on water pump with small pulley.  If I can get away with not using it, that would be preferable.  But I don't mind going that route if it becomes the right decision.

Also, I'm not really going for a "bulletproof forever as my only source of power" setup, it's really more of a "minimal damage to the engine due to the high thermal cycling rates and short duty cycles" setup.  The thermostat I figured would get the top end up to working temperature faster, that's all.  To my mind that might have a positive effect on engine life.  But I'm no engineer.

Lots to do, little time to do it.  I have more projects on my plate than I could complete in a year even if I wasn't working full time.  But you have to strive, right?  It's a lot of fun just tinkering in the shop.  Probably the same for a lot of us on here, yeah?

dieselspanner

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Re: utterpower changfa cooling conversion plate specifics
« Reply #14 on: August 09, 2018, 10:12:53 AM »
The only thing that comes close to 'tinkering in the shop' is reading about the rest of the guys 'tinkering in the shop'!

Cheers Stef
Tighten 'til it strips, weld nut to chassis, peen stud, adjust with angle grinder.