Micro CoGen.

Well winter is coming for me anyway, even though it's been 40C+ in the last couple of weeks.

I'm thinking of a few options and would like to get some feedback on things I may not have thought of.

My home is 20 Yo and all electric. No gas in teh area, no wood heating etc.  I have 20Kw of solar on the roof and adding. I have 3 phase power and can feed back to 2 of them. Unfortunately the only thing that uses the 3rd phase  is the AC which is all our cooling and heating and even on one phase, is expensive to run.
I have a few ideas to heat the house cheaply and with some independence of DIY thrown in.

First is  the 100KW gas  spa heater I have which I am going to convert to waste oil.  circulate the heater water through a car radiator probably located in a back window and use the fans to pull air in or  could just have it recirculating air in the house.  Obviously way overkill and will need to be run with someone at home and awake although I will see what over temps and controls I can put on it.
I will be using metered ( Pumped ) fueling as gravity feed despite the simplicity everyone loves is pathetically inconsistent for this application. Pumpint the oil with the tank lower than the pump and burner means  no chance of run away  or the fuel flow getting smaller.  The base controls will be a thermostat that change fueling and air from the blower from Idle to heat as the temp of the water requires.

2nd thought was a used, 400L hot water heater to take advantage of the excess power I make. Due to several factors including poor grid voltage regulation, I have a high voltage problem which trips the inverters out.  To stop them booting and turning off again all day, the procedure of which takes a couple of minutes, I have a voltage monitoring relay  Switch in dummy loads like a fan heater when the voltge gets high and the domestic hot water is already up to temp.

The thought with this was I could use the excess power to heat the tank then circulate the water same as the oil heater to put warmth back in the house at night.
400L of water taken from 90c to 20C has 32Kwh of energy! Quite a good amount.  I then recalled that there is no way I'm going to have 32 Kwh of power to spare, not in winter anyway and I'ld probably want closer to 35 With losses.  That heat would be good to have at night and in the mornings though.

Follow on thought was to use the oil burner to heat the water that first heats the tank then goes to the radiator  so the tank always has the best storage capacity possible. when shut down.
35Kw of heat on the oil heater will be a walk in the park. I'm more concerned about limiting the heat output of the burner than I am getting enough heat.

3rd option will be using a WVO powered diesel engine to drive a 12 Kw Induction motor to backfeed the grid.  The winter fall off in generation is severe so although I shut down some of my solar in summer because I have more power than even running the AC 9-10 Hour a day can burn, in winter I come up short using the AC for heating.  The idea will be to fire up the induction motor, particularly on overcast days when the solar isn't doing anything and pump back some power to spin the meters backwards and make up for what I have used and maybe a bit of credit till the next read.  I then have to let the meters advance a bit and pay something as the price of being able to use the grid as a battery.

This is also another possibility which will need investigating.
Mrs wants an outside Spa. mate has one he wants to give away.  She sees relaxing soaks. I see 3000L of thermal storage right at the back door.
this thing is electric only but an oil fired heater would be the perfect match.  With that much storage even if the water was only taken to 50C ( don't know that the materials will take on those) that's over 100Kwh of heat! Good enough for 2-3 days at least.
Not sure about this, Trouble is if I get it,  it's a heap of work to set up an area and landscape it. Then again, could be a true asset for energy storage as well.

I'm thinking at this stage to try and do all these initiatives and then see which one is best or combination of a couple.
All have drawbacks.  The oil heater I probably would not want to leave going over night. I'll have to get oil and process it and, the biggest thing, it's hardest to set it up and blend in with the look of the house without detracting from the look and standing out like a sore thumb.

The generator WIll be noisy and also somewhat limited when I can and want to run the thing.  Spose I could set up up a remote shutdown at least so I don't have to go out in the cold  to turn it off or put it on a timer. Have radio switches already that would do the job.
Unfortunately there is no opportunity to co gen with the lister and use the heat from the coolant. There is a place I could locate it at the end of the house but it would be very close to the neighbors and I can see that would quickly become a point of contention. I don't think I could enclose it in a small enough building to fit where I'd want to put it.  There is still the thing of running pipes  to where the heat would be most wanted which is not in the bedroom  which is at that end of the house.
In any case I don't think the heat output would be adequate but if it was turning a 3 phase genny, could supplement the AC.

Any thought's or suggestions?

Now we are in spring down under, the solar generation has picked up again.  with around 20Kw worth of panels on 4 inverters and 2 Circuits, I am making more power than the wiring can handle.
Before any safety sissys go into orbit on that statement, there is no danger as the main inverter with 9 KW of panels on it simply detects a high voltage and cuts out.  I plan on getting heavier wiring to the shed where this inverter is located and the existing wiring is not actualy too small, it's just too long back to the circuit board.

To keep the inverter from tripping I have 2 Voltage monitoring relays that kick in dummy loads to keep the voltage in check.
It annoys me though that I am just wasting 4-5 KWh a day atm but I can't figure what I could use the power for.

I'd like to come up with something practical and useful as it seems wrong to be throwing it away atm.

I already have the hot water setup so it only comes on when the solar is working or I manually over ride it. Being a 3.6 Kw load, it pulls the line voltage down nicely but we don't use enough hot water and I only get a 2-3 hours with it kicked in.
The septic pump out is also set up on a timer so it only runs between 12 and 4 PM but it's done pumping in about 10-15 Min as well.  I also installed a separate 1.5Kw pump today for taking the recycled water and putting that on the garden. I'll do that a little later in the afternoon.
I have a hydrogen generator I have been playing with and was thinking of using the gas to run a stove but on discovering the wide range of air/ hydrogen Volatility, I'm not going to be playing with that any more. I don't need any destructive explosions bringing all sorts of unwanted attention on me.  I just burp the thing every day to see how much gas I have made. The oxygen is not captured.

I thought about filling a chest freezer with water and running that to store the cold for cooling the house in summer but a freezer won't freeze in a day so that's kind of pointless as well. I want something with about a 2Kw motor but they are normally only a fraction of that.  The only thing I have in mind ATM is a single phase split AC system put in the centre of the house and running that through the day to keep the indoor temps lower which will make the place more comfortable at night.  There is a ducted system in the house but it runs off 3 phase and I can only backfeed 3 of the 3 phases and the thing doesn't pull that much off each phase but it adds up on the one I can't supplement.
There is no point going the battery route, it would simply never pay itself back in any savings especially seeing I will only have an excess of power 6-8 months of the year.  We use a lot of power because the whole place is electric only so there will allows be a winter shortfall and an excess in summer even when the wiring is done. I'm back feeding spinny meters so I can't go backwards over a given quarter the meter is read on or I'll get put on a smartarse meter and loose all the benefits I have now with being able to use the grid as a battery.

I have about 10-15Kwh a day excess power in summer so anyone got any clever and practical ideas what this power could be put into?

Gave my veg oil burner another run today at the suggestion of someone about enclosing the output in a pile of bricks to retain the heat.

https://www.youtube.com/watch?v=r1hUL4DvJ74

Could be useful to people who want to make their own parts or even use as the core for a heating system for Hydronics or domestic hot water.

Thought I'd put this up for those of you coming into winter that may be looking for some free heat or are into metal casting.
I gave my waste oil burner a fire up to try melting copper without a furnace.  Aluminium is no problem, can do that in seconds, you just have to dodge the flying molten metal as the thrust out of the burner is a bit high.

https://www.youtube.com/watch?v=bMmHOPlsSnQ&list=UUEfdKGemqGDvpn2hSuJl2Nw

My father has a small wrecking yard and as such gets loads of WMO and tranny fluid.
He drains it from all the engines and gearboxes he pulls.
He's been complaining of his ever increasing electricity Bills. This seems like a perfect opportunity to install a small Diesel turning a 3 Phase induction motor back feeding to the grid to help supply some of his power needs and lessen his bill.  He gets quite a lot of oil especially for a small operation and burning it would mean he doesn't have it sitting around and waiting for it to be collected.

I have been using WVO for a long time but my experience with WMO is very limited.

I'm wondering if anyone has used it and in what engines? I have a couple of small aircooled China 178 engines I could set up for the old fella so would be interested in anyones experience with those. He gets a fair amount of petrol from the vehicles as well so blending with ULP would not be a problem either.
I imagine the addition of some tranny fluid would help thin the oil out as well.

Also, are there any simple and basic filtering setups people have had success with?  I'm thinking of something like an open top 44 gallon drum with some layers of cloth over the top and having the prefiltered oil tapped off from above the bottom of the drum going into a fuel filter he gets from the cars he wrecks. No big deal if they had to be changed out every week. Not like there is a shortage or cost involved with them.
Water won't be much of a problem because draining the oil himself he can keep those separated and I don't think he's ever had a car with water in the oil yet anyway.

If I could set up an engine and motor he can run even a few days a week kicking out a couple of kw/h, I think it would be a big offset to his power bill and make use of a waste product I think he has to pay to dispose of now.

I'm getting quotes from some chinese suppliers for generator heads. One company has notified me they do a Stamford YHG brushless type which they say is far better than the ST/C type I enquired about.
It's also a lot more exy ( surprise, surprise!)

I'm wondering about the difference and necessity of the brushless type over the ST models.

I have read some things that the ST type are only suitable for Lighting or resistance loads and that electronics etc requires a much cleaner and better regulated power. My practical experience has been different to that and I'm also wondering how much real world truth there is in that assertion and how much is just typical, " parrot the high road mentality without any hands on experience" as I come across on on the net all the time.

I have used a few very basic and poorly controlled generators on computers and electronic equipment and never had a problem. To me it seems that the power supplies in the gear I have seen, ( Computers, monitors, TV's, Electronic flash gear, stereo equipment and others) have very good regulation and filtering and either steps the voltage up or down and isn't particularly sensitive to frequency either.

I have never had a problem with the electronic gear I have had and I have run some good hours on some questionable generators but I'm wondering if others have any contradictory 1st hand, real world experience?

I am thinking of using one of the generators myself for a standby for home power ( meaning basically run everything)  and onselling some.  What I am really trying to find out is if the output from an ST is up to scratch for general, all encompassing use or if there is a real and tangible benefit to the output of the supposedly better heads?

George over at Utterpower seems to favour the Brushed type heads and I'm wondering what the benefits and drawbacks there are in practicality between the 2 types.

I also wanted to confirm that you can wire the links on an STC 3 phase head to give a "total" single phase output.
Can this also be done on a brushless head?

I am now one step Closer to seeing it all:

Thinking of setting up My Merc engine with a generator/ induction motor.

Does anyone know of Governors that are not over the top exy that I could put on a vehicle engine?

I don't need a whole control system, I have one of those that came off a stationary engine that monitors temp, oil pressure etc, I could fit.
Just want a basic speed control that would fit and I don't have to be an electronics genius to build or fit. 

Just reading a comment on another thread I don't want to derail, I have been also thinking about the real benefits/ advantages/ merits of Listeroids over the chinese/yanmar etc type engines.

The listers seem to be held in Holy grail like status but after playing with mine and my China/german engines, I'm wondering if they are all they are cracked up to be?
I have come to learn with a few different things that there is the 'Net legend and reputation then there is reality which can be a rather different thing. I'm not trying to put the lister type down, just get a realistic and truthful POV on the things.

One thing I was a bit disappointed with when I got my roid was it was not as quiet as I hoped. The mechanical clatter is more than I would have expected from a slow running water cooled engine. The china diesels I have would wake the dead but they aren't water cooled, they don't need bolting to 10 ton of concrete with all sorts of measures to stop them shaking the house back up the yard apart and they do the same or better power for a fraction of the weight.

The next thing I wonder about is Durability.
The Listers are of course fabled to run a lifetime with just a kind word and a pat on the flywheels every 5 years but in practice, are they really that enduring?  Do/did they all last a lifetime or was that the exception rather than the rule?
Conversely, how do the china diesels like 195's etc last with those that put big hours or run them for many years?

Then there is fuel consumption.
From what I have seen the Listers don't seem to be the exception they once were. I have read of other designs like the Chinese/ yanmar copies getting just as good or certainly in the ball park.

I'm interested to hear thoughts and experiences from people who have and use them in the real world as to their thoughts and experiences.
What do people see as the advantages and drawbacks of the different designs and what do they like or dislike about them?
I understand manufacturing quality is a big variable but I'm interested more in things beyond that and assuming they are all to an equal and decent standard.

Any other prefered types such as Kubotas etc?

I have been playing with my Induction motor setup and learning some things.
I got the meter to spin backwards quite nicely after wiring it direct to the AC supply and was generating in both starr and delta configs with the caps set up in different arrangements.  I Did some vids of each setup I'll get round to posting on Youtube as well.

The motor I have is a 3 phase 5.5 HP, 4Kw unit. It is wired with 3 legs coming out of the machine.

I did a Vid of it the other day producing over 2.1KW when being driven by my little 165 2.2Kw Rated Diesel. Don't understand how that is possible but I measured it several ways and it seemed to be correct.



After I was playing with the thing, I noticed some C 2C wiring diagrams and realised I had the thing wired wrong.  I put the caps across 2 legs and took the power off the pair that had no cap.
Today I went out and rewired the setup by just moving 1 wire so the output was across the C1 pair. Instead of the expected improvement, I couldn't get he machine to come near holding the load. The open circuit voltage would be over 600 ( yes, I know, not good for 450V caps) but as soon as I dropped the stove element load, the excitation would crash. I tried it with 500W loads and it was OK but a lot more variance between no load and loaded voltage.

I then re wired it across the 2C legs and the same results.  When I tap the load across the legs with no cap, the engine holds the load no problems and the variance between the open circuit and loaded voltage is a lot less.

Is there something I'm Missing?
Every C2C diagram I can find shows the load tapped off the C1 legs. Tapping it off the legs with no cap works much better on my setup.


I also found this paper: http://journal.uniten.edu.my/ojs3/index.php/jee/article/download/263/99

Which mentions a C2-RR configuration that supposedly increases the efficiency of a C2C setup from 50% to 86%.  ( page 3-4 on the PDF)
I tried it without ballast ( as there is no indication what cap value or resistance to use)  and just using various light loads in addition to the main load but couldn't get any advantage out of it over just wiring a cap across each leg and using 3 individual phases. I used the Double cap value I use in the C2C setup which should have worked if anything was going to.

I have to admit I don't really understand the paper descriptions so I was wondering if anyone could put this into simple language for me?
They refer to 2 phase power which I take to be 2 phaseS as far as I'm aware there is no such thing as 2 phase. It's either single or 3 phase.
The way I read the paper, I should be able to get my 2Kw off one phase and another 40% of that off the other phase.  This doesn't seem to be the case so I'm wondering where I'm going wrong? I want to be able to get max power off a single output or at leas 2-2.4KW as our standard appliances are rated up to. Also makes load balancing a lot easier.

The caps I was using for the C2C were 50Uf and I connected 2 in series to get the 25UF on one side. I tried 50 and 100 but clearly that was far too much and the motor was creating significant drag even with no load at all.  Halving the caps worked perfectly.

One thing I noticed with the setup was again, the legs that had NO caps across them held the load a lot better than the one that did.
I was going to wire Both outputs across the 2 legs with no caps but in testing this arrangement I gave the engine too many revs and got the voltage too high trying to stabilise the start up load and Fried My killawatt meter. Bloody annoying and I lost interest after that.  Time for that new AC Current Clamp Meter. 

Can any of the boffins here shed any more light on how to practically set up this C2-RR config?

I look at the net as the greatest encyclopedia ever created. I have learnt so much about so many things that I would never have known about otherwise nor would people have had the opportunity to share.  One of those things is subject matter related to this site... Diy, Power generation, engines etc.

What REALLY ticks me off is every time I do a search for generators or power generation, alternative fuel or anything related, Google and my favourite, Youtube, throw up ( and the term is appropriate!) loads of idiotic garbage about " Free energy Generators"  and "free power"  and "HHO Generators.
There seems to be getting more and more of it.

I'm fed up with this crap! I can't believe people are so damn stupid and ignorant to fall for it nor are there so many people peddling it.  None of this rubbish has ever been proven to work, it's been in fact debunked so many times in so many ways by so many people and institutions it's  incredible.
Why it's not been outlawed is beyond me. 

I look for creditable information and examples of what ideas and things people have set up with real world technology, as boring and done as that may be. I'm not interested in dreamers and idiots that believe in the "free energy fairy" and pixie dust.  I want real info and not to have to sift through endless garbage from morons or con men and you would have to be one or the other to champion this rot in any way shape or form.

Maybe I'm the real moron.
I know sales and how to convince people and I'm good at it. Instead of getting ticked off with this, maybe I should be jumping on the bandwagon and cashing in on it too.
How can you go wrong?
If someone complains it doesn't work, you tell them they did it wrong.  According to the believers in this crap, anyone that does not create their own miracle and break every law and rule of every known applicapleable science must be doing it wrong because it's a proven fact it works right? Just look at all the other dreamers on the net that swear by it. 

If someone really bitches, give them their money back and you are in the clear. For every refund you give there will be 50-100 suckers that tell you how well your garbage works. Just create a set of really detailed " Plans" that the morons that believe in this stuff who inevitably can't nail 2 bits of wood together can follow.
Start with pictures and descriptions of what a hammer is, how it works and what you can do with it and go from there.
You can't get too basic for feeble minds that would pay money to own "Plans" for this rubbish.

There are a whole range of scams and cons that are illegal, this crap ought to be outlawed as well.

Been thinking about this for a while but a post today prompted me to start a thread to ask.

I live in Suburbia and while I haven't had neighbours in the houses either side of me for a while, The racket of my own engines means I don't run them as long as I would like. In order for me to put them to some real use, I'm going to have to shut the damn things up.

I have a variety of engines from Horizontal and Vertical China Diesels, a German Hatz Diesel, some Various petrol engines and the roid.
I'd like to start off with making an enclosure for the little Horizontal or vertical china engines that would be portable.
By portable I don't mean put it in the back of the car and take it to a picnic but I have a couple of Rolling frames around the place they would fit into and I'd like to enclose them.

Being they are aircooled is where I am a bit uncertain. Easy enough to put the exhaust out and put an inlet pickup from the outside but what are effective ways of ventilating the enclosure for the engine heat?
The greatest racket from these engines is mechanical Clatter so openings in the enclosure need to stop too much noise escaping.

For the walls of the enclosure proper I was thinking of using some plywood with insulation bats Glued/ secured  to the inside of it.  For venting I was thinking of a fan at the front and a hole at the back with a cover over them which was spaced say 4" out and ran down a foot so there was no direct path for the air/ sound to the outside of the enclosure. Again I would line the ducts with insulation material to hopefully suppress the sound.

I am concerned If I use an electric fan if something trips out and the ventilation stops and on that score, I was wondering about having the vents in the floor of the enclosure and at the top to allow for some draft to occur. How the air movement off the engine would affect this i'm not sure.

I would be interested to hear  and hopefully see some pics how other people have sound suppressed their engines Including Listers.
I'm not going to do mine yet as the house is on the market and no point ATM but I do want to set it up wherever I go to be able to provide power if ever I need it.
Being a water cooled engine will make the job a lot easier and I might also put it with my mercedes engine If I have room to build a large enough enclosure.

What have people found the best ways to silence their engines?

Not sure if this will be of a lot of interest to people here but thought I'd put it up anyway.

I have had this proclivity for waste oil burners for longer than I care to admit and actually got into the whole veg oil thing through looking for info if anyone else was playing with them. I have built quite a few now and put them to work for a range of things from heating veg oil for Bio making, re-powering gas hot water heaters, WVO drying, metal melting and even firing up my wood fired Pizza oven in times of Fire ban ( no solid fuel allowed).

The goal I had from the start was to heat my swimming pool. I have learned a lot as I have gone along building the different size burners and today got the burner going that I need for what started me out on this oily preoccupation.

I was aiming for around 220 Kw to use this with a heat exchanger I have. The new burner and big blower exceeded that quite well. best I have got out of the blower so far is about 200Kw but that was pushing it and the thing really was undersized for that output. Ran too hot, noisy and too much back pressure.
A bigger unit with a larger air intake was needed and today I fired my biggest burner so far up.

This was the very first run of the burner and I'm pretty chuffed how well the thing lit up and ran. After the paint burnt off the extinguisher bottle I throttled it up on the air and fuel and off it went. I can probably get a bit more out of it as I think it was still slightly lean. The fuel feed was gravity through an 8mm hose from a drum about 3.5 feet elevated. I'll stack up another milk crate and throw in some thinner oil tomorrow and see where I can get it.  A size up on the hose and copper tube I use to fed the oil in would probably help for max output but in reality it's doing more than I can use now.
The oil is just fed into the pipe the air enters and is blown in. There is no atomisation, it merely evaporates when it hits the red hot surfaces of the bottle. I preheat the burner with a bunch of newspaper, sticks and wood and some used veg oil .  I start the blower with the inlet closed off which still somehow give a good bit of air and when the thing heats up I add the oil slowly and off she goes.

After the vid I choked the blower intake right down for about a minute to let the oil pool inside a bit then opened it up. The flame became much longer and intensely bright and I thought the noise could well cause the neighbours to panic and call the cops or fire department as it had just got dark and the light was freaky with the noise. It still burned perfectly clean though ( while it lasted) so I think there is more to be squeezed out of this unit yet. :0)

I have another smaller one of these type burners I have put under a gas water heater and I was able to BOIL the 100L of water in a tad under an hour. Efficiency wasn't great for the fuel burned but it was pretty quick in heating the water.  With free fuel, efficiency isn't the biggest worry.
As well as being useful for off grid water heating, the other idea I had for the water heater was to run a circulator pump and have a radiator with a fan drawing through it for home heating.

I intend to make a "T" for the top of the big burner to disperse the heat output along the length of the 200KW rated water heat exchanger I have and use that to heat my  Pool. The idea I might look at is to take the pool heat right up in one burn every few days or maybe a week and then just have a pump circulating the water through a hydronic system under the house or outputting warm air through radiators.

Following a discussion a while back about using a regular car alternator to charge Batteries where the opinion of some was they wouldn't last, I decided to put it to the test.

I grabbed a couple of small frame, internal fan 80A Mitsubishi alternators and hooked one up to one of my Vertical Chinese Diesel Engines.
Using a couple of car battery cables, I hooked the alt to a car battery with a multimeter to monitor Voltage. I then used 3, 12 to 240V Inverters and a pile of 12 Headlight globes and Radiator cooling fans for a load. I don't know what the load actually was in watts, I just kept piling them on till the battery voltage went below 12 V and then I knew I was well over the alts capacity.

The alt was driven at around 5000 RPM. I have this engine a bit throttled back on the governor so I estimate it's doing about 3500 RPM and as it worked out, the serpentine pulley I had on the engine was exactly twice the size of that on the alt.  I had a bigger pulley off the original Subaru engine everything came from but it was  a neat 1" where as the shaft on the diesel is only 3/4 so I took the pulley off the Power steer pump and bored that from 1/2" to suit. I manually sped the alt up ( a lot) with the alt at full (Over) load and it didn't make any difference to the voltage at all meaning it was maxed out electrically and extra speed wasn't going to help.

I have done a few runs with the alt overloaded as evidenced by the battery staying under 12V Which took a bit of tuning to not let it discharge too quick at which point the inverters trip out on their low voltage setting.  All Up I have done around 8.5 hours so far.

While the alt gets hot and gets hot fast, I notice at the back of the alt where the electronics are, the temp there is markedly cooler than towards the front  where the windings are. On this alt I can put my fingers on the rectifier and it takes a while to discern any real heat from the thing. The front of the casing is a different matter and that gets too hot to hold ones hand on for more than a few sec. That said, That still pretty cool because my pain threshold with heat is low at about 60oC so it's still pretty cool really.  I have opened the bonnet of my car plenty of times in summer and couldn't put my hand on anything in there.

There is an impressive amount of air that comes out of this alt as well as quite a bit of heat. I reckon they would make a great fan heater if you  could capture it!
I connected the 2 wires that come out of the alt together. I'm not sure what was what. One seemed to collapse the field when put to positive and the other one seemed to allow the voltage to go well over 15V which was the same if neither were put to positive. With both wires joined and put to the positive side of the batt the alternator held 14.58 volts very steadily and was still above 14V with 800+w Load.

With the batter voltage under 12V even for 3+ hours, as soon as I took the overload off, the battery voltage with the alt going came up in about 30 sec and leveled out at 14.5+V One thing I did was to have a load of about 800W on the alt and take it off the battery so the alt was running the load direct. I did this for about an hour and 5 min and the alt wasn't that hot nor did it suffer any ill effects.

While this is a very short test compared to what off gridders may put on a machine to charge their batteries, I can't see any reason these things would fail charging a battery bank or providing power.  They certainly don't seem efficient, I was surprised at the amount of fuel the little engine went through and I have just cleaned the pump and injector and tested both before the test as I hadn't used the engine in a while.

I'm sure over all a modded alt like the ones Bob does with the outside controllers would be far better for an everyday solution particularly from an efficiency POV  but for a cheap, simple, high output and occasional use solution, I have every reason to believe these alts would not burn out if over loaded and would give many hours of trouble free service in a battery bank charging application.

As promised in the 12V battery charger thread, I picked up a couple of Mitsubishi 12V/ 80A alternators and torn one down for a look see in refrence to them being suitable for battery bank charging.

The question was if these alts were suitable for long hours at full output.
I have taken pics that I will post up shortly but my non qualified opinion from what I have seen so far is that I have no doubt these things would handle their rated loads no problem.

The alt I am referring to is a twin internal fan model off a Subaru but is fitted to a number of other makes as well and I have also seen in my curiosity that the Bosch alts of the same style should be just as capable.

The significant thing in the design of these alts is they have 2 internal fans and the rearmost one cools the Diodes and regulator.
To this end, in pulling one of these things apart, the rectifier is of a finned heatsink design that the fan sucks the air right through the middle of.  The regulator is also placed in a position that would get a very strong airstream which would also afford great cooling ability.l

The coils have their own fan and in addition, the coils themselves are also in a rather open design that would have to help with cooling.
The case is lightweight alloy and very well ventilated itself. I was wondering if cooling could be helped by the drilling of extra holes but that seems to be well covered by the manufacturer. Anywhere there would be airflow is already ventilated as far as I can see.

In referencing Bob's paper on the leece units, pretty much all the differences apply to these alts in the battery charger config as he noted. The main one I can see being the things operating outside a heated engine bay.  Pulling ambient air through the electronic side of things would have to be a huge advantage to the longevity of these units and given the under bonnet temps of modern vehicles, in a stationary application they would have to be 50oC better off. That's a significant amount in heat dissipation ability.

I also noticed that the brushes are real easy to get to on these units with just the removal of a plastic cap. I plan to drill a hole in the casing to feed a couple of wires through and attempt to solder a couple of wires so I can full feed the rotor. Removing the reg wouldn't be easy but taking it out of the equation by drilling a hole through it or similar would be a piece of cake. One could then use something like a simple tail lamp to control the rotor current and switch them in parralell for different current outputs if one wanted to limit it.

My goal is to see what the things will take flat out however.  So far I see no reason these couldn't be externally controlled exactly the same way Bob did his. While the output on these units may be lower in some cases, the giveaway prices they go for mean a person could run 4 of the things with spares and still be way in front.
I see no reason efficiency couldn't be increased the way Bob bettered the leece units.

I'll have a crack at a flat out test of one of these things next week. I have got all my inverters up and running and can pull a load on the alt over its rated capacity with no trouble. I'll try to add in load till the volts drop and then see if I can hold the alt there and give it a good long run to see if any magic smoke escapes.  If it survives that, I'll try giving the rotor all the juice it wants and see how I go there.

I'm feeling confident these units will stand up to all the abuse that can be thrown at them.  The internal design seems aimed at keeping everything cool and when removed from the environment of an engine bay, I really think they will just be cruising even when giving all they have.

When going through the pile of alts at the yard, I noticed that even though they are all the same, the part numbers changed. They seemed to get higher the later the vehicle they came off.  I noted previously that of the 2 on my lister, one runs hotter than the other. I'm now wondering if this is due to the alts being a different series/ part number. I haven't looked to verify they are but given how many I went through in the yard to find a matching pair, I'd say its possible.
As such I'll just re-assemble the one I have taken apart and us one of the others for the testing in case I do blow the snot out of it.

I'll put the matching number pair on the lister and see if they run more evenly temp wise or maybe what I am seeing is just a manufacturing tolerance thing.

I have been hunting round the net looking for a calculator or some calculation I could understand but not being too bright with these things, have come up without an answer.

What I want to know is what the heat transfer rate from hot gas ( say 500oC) is to water ( Under 20oC) through 2" steel exhaust pipe would be. I don't have the flow rates for the gas nor the water but something rough will be very helpful.

The practical situation is I want to know how many feet of 2" Exhaust tube I need roughly to transfer the heat from my 200Kw/ hr Waste oil burner into water to heat my pool and home.  I'd like to get something pretty efficient so If I have a ball park figure I can always add some length to make sure I have enough area.
I realise there are a lot of different parameters but this is backyard engineering rather than pure science so close enough will be good enough in this case.

If anyone could give me an answer in BTU/ Kwh per Ft/ meter for the pipe or point me to a simple calculator or take an educated calculation as to how much length of pipe I need to sink the 200 Kw of energy, I'd sure be mighty appreciative.