Micro CoGen.

there are many folks living in small to mid size communities, and some in large cities where they might be able to use
a cogen, "if" it makes economic sense, and "if" the thing is quiet enough not to upset the neighbors, and "if" the exhaust is
clean enough not to be seen or worse smelled.

so this is what i am thinking, and this comes on the heals of my decision to buy a house in town, that has natural gas available.

perhaps a small 4 cylinder gas engine coupled to an st12-15, along with all the other neat driven component i wanted to use
anyway, such as battery charging alternators, A/C compressor, waterpump, etc

here is my thinking, we routinely think of a gas engine as being less efficient than a diesel, and the is generally so, however

when we are considering a prime mover for cogen, where we are recovering the waste heat available, is there really a difference in
overall efficiency between a gas vs diesel prime mover in cogen?   i don't think so

certainly a gas engine converted for nat gas or propane would be far cleaner than diesel in particulate matter, and if it use a catalyst probably CO and nitrous compounds.

heat exchangers for the cooling system would be a wash, whatever works for one will certainly work equally well with the other

heat exchangers for the exhaust would be likely better overall on the gas engine if only because they would not carbon up like those
exchangers typically used on diesel engine's

then there is the epa angle, the epa doesn't like diesel and they are not likely to change their position anytime soon as i see it, so

maybe it is time to at least start the discussion on the use of a automotive 4 cylinder gas engine fitted with a nat gas or propane carb?

most will make 20-30hp at 1800rpm, all have excellent cooling system, in place, all have excellent oil systems complete with real filters
there are likely millions of them available out of wrecked cars at very reasonable prices or bought from rebulders for about the same price as a surplus center yanmar 2banger diesel

i am thinking why not take for instance the 2.3 liter ford engine, it has a proven history as being a tough sonofabitch, there are high compression pistons available should one want to increase the mechanical efficiency of burning natgas or propane. they run quiet, require no concrete to mount, have high nickel content blocks meaning they will wear forever with good maintenance and clean air/fuel.

so the pro column might include

1. widely available
2. competitive price
3. relatively quiet operation
4. reliable and long lived
5. excellent cooling system design
6. excellent oil/lube system design
7. parts are widely available and relatively inexpensive
8. reliable and cheap electric starter
9. easy to mount, requires no massive concrete base
10. can be easily converted to run on gas, nat gas or propane
11. accessory drive capable for added driven components, many mounts readily available
12. certain models were rated for peak torque at 1800rpm making them a good match for direct drive generator
13. possible to run engine on wood/producer gas or methane


list of cons

1. it is not a diesel so it cannot readily run on waste oils
2. has an ignition system that will require periodic maintenance and parts replacement, (spark plugs, cap/rotor, wires)
3. physically longer package for direct drive than a belt driven diesel genset of even a direct drive genset
4. runs at 1800 instead of 650-1000rpm, (not negative comparison to a changfa, but certainly as compared to a lister/oid)
5. requires a connection to nat gas (city) or propane (offgrid or where nat gas is unavailable)
6. *add other cons to this list

i am only suggesting perhaps it is time to at least think about and discuss this option, it doesn't have to be a 2.3 ford, it could be any number of small 4cylinder engine's. i only suggest the 2.3 because of it long production run, its proven reliability and availability of both the used engine's and repair parts.

personally i am going to give this some serious thought

bob g

an added thought

if as a group it was decided to go with a specific engine, it would make the project more doable for everyone
all sorts of things could be engineered and replicated, such as mounts, drive systems, manifolds/exchangers etc.

making it to where everyone wasn't reinventing the wheel separately over and over again.

it also opens the door to group buys of things like nat gas or propane carbs,  electronic governors, bellhousings
waterpumps, starters and all sorts of stuff that likely would reduce costs significantly over everyone doing it individually
using all sorts of different prime movers.

so what do you guys think?

bob g

Bob, I lost the whole post I just wrote. I don't have time to write tonight about the Ford 2.3 SOHC engine. All I can say is I love that engine. I built some pretty strong engines out of them. Some over 300Hp. at 8500 RPM. To bad I just sold a set of Brand new Crower Sportsman Rods rated for 500Hp for the  Ford 2.3 SOHC engine.
But the good thing is I will keep the KB Hypereutectic Piston just in case.

I will post more about that engine.

But I got some good pictures of the pistons that I was ready to post tonight.

Henry

#2

#3

#4

#5

i found a 2.3 mustang motor with bellhousing/clutch and a 5 speed manual trans for 5 hundred bucks
out here on craigslist
don't need the trans, but having the bellhousing makes making up an accessory drive very easy.
the engine is supposed to be a good runner, with 94k miles on it.

might check into it this week

bob g

Oh, Just to let some of you know that are getting confused. ???

I do know how to build a strong 1800 RPM engine out of the Ford 2.3 SOHC.

That is what is so great about this engines. They are a very flexable engine to work with.

Henry

Bob, What year is it? Just make sure it does not have a dual plug head.

got to thinking i might also be able to get a propane carb setup from a forklift boneyard, and adapt it for nat gas use.

the more i think about this, the more i am liking the prospects

i have no idea what year it is, he didn't list the model year in the ad, i will call him tomorrow and find out the particulars

bob g

That sounds good.

Henry

Now you're talkin' my language! Looks like somebody beat you to the punch though:
http://www.olympianpower.com/cda/files/2478365/7/LEHF0010-00.pdf
I've been studying those specs for a while, mostly looking at the fuel consumption rate. Who makes that 2.4L engine...GM? One thing I noticed is that it gets it's best fuel economy at full load.

When I calculate everything out, I can run a natural gas cogen and make cheaper electricity than the local utility if I'm using all the heat. I just can't decide on an engine. I'm planning a new 40x60 shop with a small basement for an engine room, I plan on using a generator as the only source of heat.

I have decided that NG is the way I am going.
That's one reason I haven't hauled home any of the heavy iron CI engines yet.
I installed an 1.25 inch poly gas line year ago, from the meter around to the back side of the house.
Gas Co. set a higher flow meter.

I do not have nor expect to acquire any source for waste oil,  and going into town for rationed fuel is way down on my list. Ultra long term was seed oil, but seriously kidding myself there.
The line I am on only has 3 other meters at this end, and was replace with poly ~10 years ago all the way back to the main line mainhole in town. And you really have to know where that manhole is. What I saying is, for me; if things grow dark I would rather take my chances on NG.

Been thinkin 2-3 cylinders simply because I don't need all the heat, but 4 would be alright.

Randall

Just to play the devils advocate here.... ;D
I know many people build stuff here, not because they have to , But because they can.

But , Just because we are changing fuel types we shouldn't be abandoning the virtues of tried and true stationary engines.

Simplicity
Cast iron
Built in governors

How about a V4 Wisconsin genset , some are OHV propane/nat gas
Air to air heat exchange for house heating
Exhaust and sump heat exchange for water heating
Megajolt ignition to get rid of the magneto or distributor and lets you play with advance curves.

I have a VE4 5kw genset project like this waiting in line..... ::)

Cheers
Keith

i didn't really think we would be breaking any new ground with the use of a 4 cyl engine with natgas or propane

what i did wonder though was whether we could effectively use one for cogen operation, and i think we can
economically as well.

having said that, it appears that the unit can be made to run very close to the same kw/hr per btu of fuel consumed
based on the guardian units numbers, and likely those numbers would be improved if the engine they used was significantly
higher comp ratio than their 8.5:1

it would seem that there equivalent to 9kw/hr/gal (adjusted for diesel comparison) could be improved to around 10kw/hr/gal
if the comp ratio was increased to 10:1 or greater.

the problem lies with being able to use the available power afforded by the 4cylinder in order to get to max efficiency, and i don't see
that happening for the average small home for continuous operation, however

i can see the possibility of very good overall efficiency if there is some level of automation/control where the unit is tightly controlled
so that the available power and heat is used effectively and matched to the loads which would require scheduling along with likely
either a grid tie scheme or battery/inverter system.

it might work something like this

the house is cold, there is need for hot water, and also a load of laundry to wash and dry, so the unit is started and all electrical loads are switched over to the cogen. it powers all electrical loads and pumps the harvested heat into the thermal mass of the floor or other storage medium and whatever extra capacity is used to offset the utility power that is used to power the lighter loads while the cogen is shut down or the extra power is used to drive an alternator(s) to recharge a battery bank which in turn would power the lighter loads during cogen off time.

this would allow the cogen to operate on an intermittent basis, and allow it to run at peak efficiency.  with sufficient thermal storage
and good scheduling the unit ought not have to start more than a couple times or at most maybe 4 times a day during cold weather.

even at a half dozen starts per day, the quality starter ought to last at least a couple years before needing replacement.

the one fly in the ointment is the unit likely could not be used efficiently in warmer months where there would be no use for the amount of heat available, unless some develops an absorption chiller/cooling system to air condition/cool the house, then possibly it would math out.

otherwise a much smaller unit sized for summer loads would be a better match, something like a geo metro motor (750cc 3cyl)
or maybe one of the kohler water cooled twins might be a better match?

as for aircooled engine's, why not give one a whirl

if it is mounted in an enclosure and a refer compressor is used, the aircooled heat can be harvested, transported and used cleanly and safely into a living space, via a heat pump scheme.

bob g

Hey Bob,

Take a look at this site...it provides only snippet info...but they provide a lot of snippets on many issues.

Lloyd


http://www.brighthub.com/engineering/marine/articles/75641.aspx (http://www.brighthub.com/engineering/marine/articles/75641.aspx)

QuoteIn this article we discuss dual combustion engines and the advantages of propane injection in diesel engines.
Introduction

All marine diesel engines in operation worldwide are slowly changing into dual combustion engines (DFDE, or Dual Fuel Diesel Engines) that operate on natural gas and marine diesel heavy fuel oil. The dual combustion engines are gaining more importance due to their efficient performance and proven reliability when compared to diesel engines, which are highly prone to pollution.

Natural gas ignition engines provide ultra-clean combustion, thereby reducing the pollution that will obviously reduce health hazards. Most of the natural gas engines are operated both on natural gas or gasoline and these engines based on the Otto cycle are spark ignited.

All diesel engines in LNG and LPG carriers are slowly changed over to dual fuel diesel engines because of the advantages of the gaseous fuel resulting from the vaporized liquefied natural gases in tanks during sailing.

This gaseous fuel is nothing but the propane-based gases vaporized from the liquefied natural gas. Dual combustion engines are able to consume this gas and convert into useful energy in cylinders. Normally during sailing the gas involved is completely used in these engines and the same engines use diesel as fuel during maneuverings in port.

Lloyd

thanks for the link, i spent a few hours late friday night reading up on the lastest in dual fuel diesel operation
and it would appear there is ample evidence that natgas can be used as the other fuel in an otherwise unaltered
diesel engine.

i found a few references to there being no need to reduce the compression ratio once thought as necessary for operation

that was encouraging and supports the use of our diesels with natgas in dual fuel mode.

my shift to spark engine thinking is based on the increasing difficulty in getting small diesel engines because of the epa
while i have enough to keep me going for the rest of my life i fully recognize our hobby if you wanna call it that will at some point
expire due to the lack of sufficient supply of compliant engine's that are within the budget of a diy'er..

obviously there will always be engine's that are compliant to use if you have enough money, but there is a finite source of older engine's even if you scour up all that are sitting in barns in other countries and ship them,,, at some point the replacement parts will become an issue as well.

take the witte engine for example, here is a wonderful old piece of history and solid engineering, but they are few and far between
and parts are getting difficult if not impossible to come up with.  at some point the listers will be the same i fear, the chinese engine's are already a problem to not only get, but to get parts for as well.

as for dual fuel diesel, i will be keeping my trigen and it will likely be dual fueled with nat gas now that it appears that i will have access to that fuel source.

thanks
bob g

The germans are in with bob in this .
http://www.vaillant.de/Produkte/Kraft-Waerme-Kopplung/Blockheizkraftwerke/produkt_vaillant/ecoPOWER_Blockheizkraftwerk.html
Its in german ,a translater can translate it ,got a 1kw honda micro unit and some bigger ones 3to 4,7kw .

But its a crappy site .

Here is a link to my listeroid running in dual fuel mode. the governor will control the amount of diesel to the engine the natural gas is set using a needle valve. While this is not ideal, under a 2k load the ratio is about 80% natural gas and 20% diesel.  If the load increases the ratio of diesel to nat gas increases as the governor pulls the rack open some more. If you have a constant load on your engine, it is real easy to fine tune the adjustments.  The gas solenoid is powered from the gen head so if their is any failure in the engine or generator the gas is shut off.

http://www.youtube.com/watch?v=AwPPui8Fyi0

One question I have is would direct injection be better for dual fuel mode or it does not matter.

Henry

Quote from: Carlb on December 13, 2010, 03:56:04 PM
Here is a link to my listeroid running in dual fuel mode. the governor will control the amount of diesel to the engine the natural gas is set using a needle valve. While this is not ideal, under a 2k load the ratio is about 80% natural gas and 20% diesel.  If the load increases the ratio of diesel to nat gas increases as the governor pulls the rack open some more. If you have a constant load on your engine, it is real easy to fine tune the adjustments.  The gas solenoid is powered from the gen head so if their is any failure in the engine or generator the gas is shut off.

http://www.youtube.com/watch?v=AwPPui8Fyi0

Very cool and similar to the experience I had running propane/SVO several years ago.  I got to about 85% propane under a 4.5K load.  Documented here in the "Diesel/SVO/Propane Control System" photos/descriptions:

http://listerenginegallery.com/main.php?g2_itemId=351

Bob B.

BobB

is that 4.5k mechanical output, or 4.5 kw electrical output

and iirc you are running a 6/1 at 650rpm?

trying to get my head around a bunch of reports from various sources supporting the theory
that even though the engine is ingesting fuel of a lower btu value it is still able to make as much or more power
which can only be explained by a more efficient, more complete or an altered burn rate that the engine is better able
to convert to useful output mechanical work.

an earlier discussion centered around a university of wisconsin project where they dual fueled a CAT engine with gasoline
via a low pressure port injection scheme taken from the gas engine automotive application common to cars. in their report
the demonstrated an efficiency increase to something over 52 or 54% from the oem engine running on diesel alone of 41% efficiency

this is something that fascinates the crap out of me, and something i want to fully explore, test and understand.

just finding papers supporting that it is not necessary or even desirable to reduce the comp ratio on a diesel engine to run it in
dual fuel mode supports earlier crude testing i did on the s195 over 5 years ago now, it too inhales propane quite happily without any signs of detonation or preignition and it has a 20:1 comp ratio.

it even ingested rubbing alcohol without complaint at that time, more recently i tried gasoline via the drop method and it too presented no signs of roughness or knock which would indicate detonation problems.

definitely not enough time to do all i want to do.

the upside is a dual fueled diesel that is used for combined heat and power, using output based emission standards would have no problem meeting the most stringent epa regulations, likely without any particulate filter, no urea injection and maybe not even a cat.

probably be a better neighbor too, in that it wouldn't smell like a diesel

bob g

With the recent collapse of natural gas costs due to the shale gas plays in the USA,  a spark ignition  genset makes perfect sense.

  I have been driving propane fuelled trucks on and off since  1982.   I have driven  + 250,000 miles on propane.  My motorhome is on propane.  (single fuel)  With the compression upped from 7.8 to 9.5/1  and the ignition recurved, and a few other minor mods it makes far more power than it ever did on gasoline. I completely shame diesel pushers with my 350 chevy spark ignition propane engine. It's an 82, on propane since 1987.  I had the heads off at 90,000 miles and the short block was still like new. I had to re/re the intake manifold last month and it still  looks like a compresor inside,  Ultra super clean inside  at 169000 km on the block, 28 years old, and 8500 pounds down the road, with 4.11 gears, no overdrive. Comp is 180 on all 8 cylinders.  Gaseous fuels are the ultimate spark engine fuels!

Propane is c3h8,  natural gas is primarily methane, c2h5. So for automotive use the NG is less desirable as it has much less BTU output, and liquefies at high pressure. But for a stationary set it makes perfect sense, especially if it is cheap. And it will be cheap for many years, as the shale gas plays are ramping up big time,and  the Alaska and NWT gas pipelines will be very soon constructed. Experts expect the north american ng market to be depressed for decades.  And conversion from methane to propane  is pretty easy, if you need backup due to being in an earthquake zone

I'd recommend a post smog , all iron inline engine like  a Chev 2.5  or a Ford 300/6 . Or an old Datsun 1000/ 1200 for the smaller sets. Or a Yugo 1300 (lol)  Make sure you have good hard valve seats on these applications. Engines made for leaded gasoline will clap out their valves pretty quickly on gas.

Bob G.

That's 4.5K electrical from ST5 driven by 6/1 at 650 RPM...three 1500W portable heaters and confirmed on the transfer switch watt meter.  Frankly, I never made logical sense of it, but Quinn at the time seemed to explain it as resulting from more complete combustion that allowed for greater BTU extraction than one might expect by say averaging the propane and SVO BTU values.  I think he may have even posted the combustion equation at the time...likely on George's site.  I'm afraid that chemistry was not my best subject, so this is well beyond my capability to attempt to explain properly.  ???  

I can say that the propane demand regulator I use is designed for much more than 6 HP, so it is not flow rate limited when under high load.  Same story for my CO2 regulator that is used for emergency shutdown.  As you know I tend to push design limits by radical designs and over-designing...  If I recall correctly, I think I got my propane regulator from this place:

http://www.propane-generators.com/a-c_kits.htm

Anyhow, the only limitation I encountered during this experiment was the minimum amount of SVO required to maintain good ignition and my fear of exceeding the ST5 5KW rating.  The 6/1 didn't seem to mind this experiment at all and it actually sounded like it enjoyed it.  In fact, the 6/1 always seems to run smoother/quieter even when just running my normal 10% propane fumigation level used for carbon removal.

Bob B.

PS - The primary reason I run SVO and propane is so my suburban neighbors can't detect my operation.  And this was my primary motivation for going with a resilent mount design too. :)

Quote from: mobile_bob on December 13, 2010, 08:21:53 AM
the one fly in the ointment is the unit likely could not be used efficiently in warmer months where there would be no use for the amount of heat available, unless some develops an absorption chiller/cooling system to air condition/cool the house, then possibly it would math out.

otherwise a much smaller unit sized for summer loads would be a better match, something like a geo metro motor (750cc 3cyl)
or maybe one of the kohler water cooled twins might be a better match?

This is the brick wall I always hit. We don't need a lot of heat here. One option might be to build a 4 cylinder generator for winter months and maybe a 2 cylinder for summer use. That way you always have a spare when one is out for service. Has anyone tried to use engine heat directly in a clothes dryer? If I had to guess I'd say that burns the most electricity in my house. I also have a hillbilly 5000gal above ground pool that needs heating every month except august...(don't use it in the winter)

I am hoping to build a "micro" cogen system much like the 1kw Honda unit for my house...I'll need something much bigger for my new shop though, and I want to power all sorts of shop tools with it too, like an air compressor or welder.

Another interesting use I've been considering is a greenhouse to grow food crops, which would need lights and heat in my climate much of the year for part of the day. The key here is that CO2 is fertilizer to plants, and running clean natural gas exhaust into the greenhouse can increase production by up to 30% while heating at the same time.

there sure seems to me that there has to be some alteration of the burn rate with the dual fuel operation
vs standard diesel operation.

diesel fuel is injected, then there follows a delay period, after which ignition occurs marked by a sharp pressure rise
(that diesel knock we are familiar with) it stands to reason that perhaps this sharp pressure can only affect the crank over
a relatively narrow crank angle, whereas

with the propane dual fuel, perhaps the pressure rise is not as sharp, but rather spread out over many more degrees of crank
angle, allowing the engine to make more effective use of the combustion event, converting it into useful torque?

there has to be something to this phenomena, it can't simply be explained by the use of additional propane to make up for
the loss of the fuels btu content, because the engine is naturally aspirated there is only so much air available to burn additional
fuel.

typically we see 6/1 pulling 3kwe relatively cleanly, over that they begin to smoke indicating that there is too much fuel for the available air.  the same engine pulling 4.5kwatt relatively cleanly is a 50% increase in output power, in order to account for that
simply by virtue of added propane to make up for the offset in btu's does not seem at all possible. the propane also displaces air
in the cylinder, so adding more propane can't make more power on its own merit, or so it would seem.

what would be interesting would be to run a test and get the amount of both diesel in gr/kwatt/hr and also lbs/kwatt/hr of the propane used. from that the story could be told.

my thinking is perhaps there is truly an alteration of the burn rate that allows the engine to harvest more useful power over a longer
crank angle than otherwise happens in straight diesel operation, and if there proves to be no offset or increase in propane to make up the lost btu's, the only conclusion left is the engine is demonstrably more efficient in duel fuel mode.

if this proves to be the case, this is where we need to be heading as a group. we end up with more efficient and cleaner engine's and perhaps the epa might look more favorably at these engine's for cogen use as well.

just wish i had natural gas where i am living now, but i guess i can wait till i relocate

bob g

while this link may not shed much light on increased output or efficiency using Nat gas in dual fuel operation
it does clearly illustrate that it is not only possible to do so in an unaltered single cylinder engine, but one fairly typical
of what we use (S1100), and it is done in a fairly widespread manner.

http://www.ijens.org/97510-7373%20IJMME-IJENS.pdf

something anyone interested in dual fuel ought to download, read and add to their info library in my opinion

bob g

I think you're on to something there Bob. Isn't the effect you've described similar to what the mfgrs are trying to accomplish by having multiple injection events during the combustion stroke on the new electronic injectors? Now I'm wondering of adding propane injection when the engine is loaded past a 3kw would be like adding nitrous to handle the over load and clean the cylinder at the same time. Add a pot to the governor and variable valve?

Bob I like it. I will sit down tomorrow and re-read it. Just got home and I am to beat to do anything tonight.

Henry

Bob

You sure can get a guy to thinking. You see I have an LP line about 6 feet away from my 10/1. Right now I am running the roid so that line is not costing me anything out of my pocket, as the propane furnace in my large shop is OFF. But if the use of some LP would conserve WMO and clean the carbon it sure might be worth the few 100 gallons of propane to get more out of both fuels.

I did test out some dual fueling a few days ago when I hooked up the lp furnace and tested it as a backup to the roid.

I will say it seemed a little LP went a long way Into reducing the fuel rack's position.

I have also thought of using a little anhydrous ammonia to do the same thing, if a guy could only bottle up the exhaust and save it for fertilizer.

Billswan

there was a coop group in canada, that got a grant to use the exhaust off their tractors while planting, the exhaust
was cooled to below 120F iirc and injected underground with the seed drill, the fertilizer offset was very significant.

i don't recall the specific's but the reduction was on the order or  75% less ammonia fertilizer to get the same yields from the crop
planted.

that is another thing i plan on testing, that it pushing the exhaust under a grow bed in the green house to see what the possible benefits might be.

bob g

Having an oversized Cogen system in the summer just means you have to shut it off when you don't need it.
I lived on a boat years ago, it had a 12Kw gen powered by a White Hercules. I ran it in the morning after breakfast, and in the evening after dinner. Longer if I was doing laundery, shorter if I only needed to do the dishes and take a shower. 12 VDC provided lights and radio.
I would start the gen if I needed power tools or to use the welder etc, otherwise, it was off.
You could run your home/shop the same way.
My friend in Granite Falls has a 4 cylinder propane generator and an Outback power systems MPPT 48 Volt battery inverter system with solar panels. The power company wanted about $200,000 to run power down his road!
He frequently goes thru the summer without running the generator at all.
You can do it easily enough, as long as you don't expect to have AC power all the time, or if most of your light duty AC loads can be handled by a battery inverter system.
I'm planning the same thing at my 'other' place.

Quote from: mobile_bob on December 14, 2010, 07:50:08 PM
there was a coop group in canada, that got a grant to use the exhaust off their tractors while planting, the exhaust
was cooled to below 120F iirc and injected underground with the seed drill, the fertilizer offset was very significant.

i don't recall the specific's but the reduction was on the order or  75% less ammonia fertilizer to get the same yields from the crop
planted.

that is another thing i plan on testing, that it pushing the exhaust under a grow bed in the green house to see what the possible benefits might be.

bob g

Got ya, I have read the same stuff but there is this problem it is time and money. To bad there is just not enough of those to go around. :'( :'( :'( :'(

Billswan

To those who frequent George's site, here's the thread on propane I was recalling that was active about the time I built my 6/1 propane system:

http://slowspeedengines.com/forum/showthread.php?t=436

A couple folks reported 500 to 700 watt power gain running propane.  I couldn't find the Quinn's combustion explanation that I strongly recall reading/considering.  It could be on another thread or it could be my recollection is not as good as I believe.  It would definitely be best to do a good independent experiment and record the total quantities of fuel used (perhaps by recording weight change of tanks after running for an hour) and measuring power load accurately.  Frankly, I don't think I trust my transfer switch watt meters to this degree and I certainly didn't calibrate the electrical load of my Costco 1500 watt garage heaters either.

Bob B.

Ok,

Now I just had an epiphany...What about SmartPlugs in a Duo-fuel. I did some research on these a few years ago, when I was working on a diesel fired Wankel, using water for flame propagation and seal cooling.and basically steam cleaning the combustion cylinder on each power stroke.

I just checked the website http://www.smartplugs.com/fuels/index.html (http://www.smartplugs.com/fuels/index.html)  it seems a logic controller to control the Propane/NG wouldn't be that hard to resolve.

Have a look (http://www.smartplugs.com/images/ignitors/SmartPlug2.gif)

Lloyd

BobB:

while you didn't calibrate your heaters, and question the validity of the power meters, it seems unlikely that both could be off
that much.

it would seem that there is enough evidence in your preliminary test to warrant further testing for sure.

bob g

Lloyd...
How is it possible to assure correct toming withe those plugs. Basically it is only a modified tube ignition.

Or.....am i missing something ::)

here is a little more light reading

it has some explanation as to what is happening with gaseous dual fuel operation
with plausible explanations of how pressure vs crank angle might explain what is being witnessed
here.

http://eprints.lincoln.ac.uk/2259/1/pgs_clarke.pdf

bob g

Quote from: sailawayrb on December 14, 2010, 08:40:20 PM
To those who frequent George's site, here's the thread on propane I was recalling that was active about the time I built my 6/1 propane system:

http://slowspeedengines.com/forum/showthread.php?t=436

A couple folks reported 500 to 700 watt power gain running propane.  I couldn't find the Quinn's combustion explanation that I strongly recall reading/considering.  It could be on another thread or it could be my recollection is not as good as I believe.  It would definitely be best to do a good independent experiment and record the total quantities of fuel used (perhaps by recording weight change of tanks after running for an hour) and measuring power load accurately.  Frankly, I don't think I trust my transfer switch watt meters to this degree and I certainly didn't calibrate the electrical load of my Costco 1500 watt garage heaters either.

Bob B.

Well, I can't read the post, AND registration is disabled! Reckon George would be torqued if the post was reposted here with
credit where credit was due?
Ron

I'll vote for a repost, I too was blocked from viewing

Quote from: mike90045 on December 16, 2010, 08:02:21 AM
I'll vote for a repost, I too was blocked from viewing

The referenced post is several pages long.  Reposting might be something that the Admin of this site could do after coordinating with the Admin of the other site.  While the referenced post contains some worthwhile info, I think the reading material Bob G provided in this thread may be more worthwhile.

Bob B.

Just a thought regarding governors. We "generator heads" love the diesel's centrifugal governor arrangement  but such a governor is sorely lacking from any easily available gas engine that I know of.

Since about 1990 or so when cars all became fuel injected the OBD system has controlled idle speed. Notice on a standard transmission EFI car how if you feather the clutch the idle automatically maintains the RPM?  This did away with all the carb solenoids which compensated for AC pumps, and such.  It should be a simple matter to hack into the program to get the idle to 1800, or whatever rpm we desire. Anybody know how to do this? I know that the tuner car guys can control every aspect of their OBDII cars from a laptop, so these old dinosaurs should be easy. 

Unlike an automotive application there is no need to recurve the distributor....  set it to whatever total advance you need and forget it.  It's a constant speed engine we are building here. There's lots of propane and natural gas conversion  equipment is just sitting in junkyards in Canada. We had a fad for NG auto conversions in the 90's, but it died out.  Propane was a 80's fad, it pretty much died too... 

Old Chevy base model S10 trucks had a 2.5 liter oversquare pushrod all cast iron TBI engine.  Same engine in Fiero's...   It was a tank of an engine, all torque and no horsepower.  A 2.5 liter TBI chevy pulled from an S10, set up with the ECM hacked to make it idle at say 1200 rpm, with 25 degrees total advance, belt driven to an ST head, running on natural gas. It would be almost silent.  If you need less displacement just take out two piston/conrod assemblies, and 4 pushrods.  Voila! Instant 1.2 liter 2 cylinder industrial gas engine with ECM controlled governor. Ultra cheap.

I think the trick is to find a junked old fleet truck that had been converted to NG and build from there.

Quote from: TimSR2 on December 16, 2010, 05:32:19 PM
Since about 1990 or so when cars all became fuel injected the OBD system has controlled idle speed. Notice on a standard transmission EFI car how if you feather the clutch the idle automatically maintains the RPM?  This did away with all the carb solenoids which compensated for AC pumps, and such.  It should be a simple matter to hack into the program to get the idle to 1800, or whatever rpm we desire. Anybody know how to do this? I know that the tuner car guys can control every aspect of their OBDII cars from a laptop, so these old dinosaurs should be easy.

The problem I see with that is that the idle speed is usually controlled with a small aux. electric valve seperate from the throttle. I doubt that would be large enough to let in enough air to run your engine at 1800...especially with a load. Also, if you're trying to use natural gas instead of gasoline, you're going to have a ton of problems trying to use the stock ECU...you don't have EFI anymore.

there are woodward and hoof belt driven flyweight governors that would work to hold the speed steady enough for a genset, also
there are the electronic servo governors that are capable of very tight control.

there is also a couple of other methods based on mass air flow that are fairly accurate once set, although they might require a bit of tweaking
depending on changes in ambient temps, baro pressure  and possibly loading.

far easier to deal with governor control than adding proper lube and filtration systems, electric start and all the other odds and ends one has
to contend with using ancient designs.

bob g

To Biohazard:

90's propane and NG vehicle  conversions always used a black box that reinterpreted the ECM signals, (they were costly at the time, 3 to 400$)  to recurve the distributor and input signals . Although the fuel injector would be out of service, the Map sensor and TPS , O2 sensor would still do their job. To increase the idle speed to 1800 we should just have to hack the software, and increase the length of the lever that the solenoid operates.  OBD feedback loops will take care of everything else.

However, I think that we can easily get the power we need at 1200, on belt drive, which should make a very nice CHP, and this should be possible without physical mods to the idle solenoid. A 2.4 liter Iron Duke should be good for 10 kw at 1200 rpm on Methane fuel if it has all 4 pistons firing.

A Marijuana grow house burned down a quarter mile from my inlaws a few years ago. It had previously belonged to friends of the family and apparently ended up being a Hells Angel grow house.   They had quietly installed 2 matching  300 cubic inch Fords on  illegal Natural gas tap intercepts driving 30 kw heads in the 2 car garage. They ran all their grow op lights on the gensets, leaving all the power for the house on the grid,so the electric company had no indication of anything wrong. They grew Millions of dollars of Pot on stolen Natural Gas, for 8 years, in a wealthy neighborhood, and the neighbors didn't hear a thing.

This on a half acre lot, with neighbors 200 feet away. It ran 8 years before a failed fuel line burned the house down. My inlaws live a quarter mile away, line of sight from this house,  and never suspected anything, never heard a sound.  It was never in the news, I only know because I have friends who are firemen.  
T

One thing I've read about, though not understood much of, are "lean burn" natural gas engines. What if one left the throttle wide open and changed the gas ratio based on engine load - like a diesel? Seems like it could work in theory but probably not very easy to control...

Could a tractor engine be used for this application the ones I am thanking of are about 154 cid and have a governor and there were a lot of them used on lpg and other fuels this would give the bell housing and maybe a gear box for drives. Tom T

One thing about the 2.5L Chevy engine is that it was used in marine applications...might be easier to find some water cooled exhaust parts.

Just heard on the news, electricity is going up as natural gas goes down.... ::)

 Tom, LP tractors used a special rare high compression head that the Antique pullers will walk through fire for and some of the old controls are obsolete, plus nearly all are high dollar collectors items.....
Sorry to pop your bubble.
Ron.

Sorry but you did not pop my bubble was just a thought that's all ! Tom T

Tom T: wow I did not know that. A Mechanical governor Iron Duke would be awesome. So much simpler!   You would probably have to put stellite seats in the head but it is not very expensive to do that. Disable or replace the exhaust valve rotators if your engine has them. You don't want valve rotation on a Gaseous fuel engine.  

On my motorhome I  shaved the heads, removed the rotators and put in  a skinny .019 headgasket.... boosted the comp from 7.8 to 9.5 to 1. That is as high as you want to go in a 'severe service' engine. The machine shop guys calculator did the math for me. The power  from the compression increase is just unbelievable. And the fuel consumption dropped too.  On a lightly loaded engine you can push it up to 11 to 1 on NG or LP.  And gaspots love to work lightly loaded, unlike diesels.   The stoichometric ratio increases as the compression ratio increases, so a large displacement, high compression engine  can be run leaner, and will be more efficient.    Iron duke 2.5 chevy has the typical studded rocker setup so the valve geometry will not suffer.


There is no need for a gearbox. Just a double 3/8 inch automotive vee belt drive off the front, or a serpentine belt system off a late 80's  Chevy s10 will do.

But I'll bet if we do some research we will find commercial gensets built on this block that are available as obsolete surplus,  so we may only need to buy one of these and add a heatex (marine manifold) to have a decent CHP system.  We may be reinventing  the wheel here.


Biohazard : that is  a very relevant observation that I should have well known, as a boater...  There are Water cooled exhaust manifolds freely available for this engine, since the 1960's.....    And they have great circulation pumps as factory equipment. Just design the heat harvest system to cool the engine first, then the exhaust heatex, , through the heat absortion load system... back to the block

I love this thread.  It reminds me of Junkyard Wars on TV, in the 90's

That old Iron Duke sounds like a winner. From 75 up will probably already have stellite valve seats due to unleaded fuel compliance.
Or... I have an old Hercules flathead four banger power unit. Anybody up for trying to modify an ancient artifact?
It's complete with magneto ignition and a crank to start it with. :D  I don't know how one would ever get the compression ratio up high enough,
it's probably all of 6 1/2 to 1.
Ron

Here's a good list of things the 2.5L was used in for craigslist searching:
http://en.wikipedia.org/wiki/GM_Iron_Duke_engine

I notice a lot of old buick century's with the iron duke on the local craigslist in the $600 neighborhood. One of those with air conditioning could really yeild a lot of fun parts to play with. You guys are are really winning me over on the Iron Duke.

I can vouch(sp) for the durability of the "Iron Duke"  It is one tough sonofabitch. Ive seen them overheated multiple times and still run out a normal life.

Rob

Yep guys this is what all of us woodgasing fellows are up to alright.
Self fueling big/er spark ignition engines at a nice quiet slow speed. You can see pictures and comments about some of our current activity on the Main page here without joining:
http://victorygasworks.ning.com/
My hands holding a turbo up to a Ford 240 I-6 in a 20kVA Onan genset. I personally DO think it would be better to compression increase it. See AlexeyA's gasifier on thier 30kVA container CHP unit. See my small spark and deisel engines, AC gen head and Elecrtodyne truck alternators, ect. It is these small units are the hard to woodgasifiy, the big stuff is Much easier

The GM iron Duke is great esicially the pickup version.
Also the earlier single spark plug Ford 2000 and 2300 SOHC engines and the Chrysler 2.3 and 2.5 SOHC engines too.

Yeah local growers been trying to recruit my work already.

Regards
Washington State Steve Unruh

On the durabiilty of the Iron Duke:

I bought a new GMC S15 in 1987,   4 speed,  no overdrive, and 4.10 rear. She was a total screamer on the highway.  I sold her after 4 years, she apparently changed hands many times, and was very sorely abused by the later owners. I met her owner about 5 years ago, by chance. He had just put  in a junkyard mill to keep her going for a while. The original engine failed at 376,000 km, was reportedly doing fine until a rad hose failure caused a fatal overheat.

Those engines are very tough.     

Was the iron duke used for industrial purposes? There may very well already be generators based on them that we could...well...copy.  :) It works for the chinese....

Quote from: BioHazard on December 18, 2010, 10:18:08 PM
Was the iron duke used for industrial purposes? There may very well already be generators based on them that we could...well...copy.  :) It works for the chinese....

Well I remember working on an lp engine in a fork lift that was a 4 cylinder older form chevy. I would think as the years went by the and the iron duke came to be it also would have found it's way into forklifts. Any forklift mechanics here???????????

I just checked the specs. 4 inch bore, same as a 350 or 302 chevy. I havent time to check if the piston pin height is the same yet but it sure would be easy to find high compression pistons if...   And the way GM 'parts box engineered' stuff I think it's likely that we can fit 350 pistons  12 1/2 to one, anybody?

Quote from: TimSR2 on December 19, 2010, 09:45:47 AM
I just checked the specs. 4 inch bore, same as a 350 or 302 chevy. I havent time to check if the piston pin height is the same yet but it sure would be easy to find high compression pistons if...   And the way GM 'parts box engineered' stuff I think it's likely that we can fit 350 pistons  12 1/2 to one, anybody?

Why stop at 12.5:1  when 15:1 are available. ;)

OK I found it. It's half of a Pontiac 301.  So the  151 Tech4 is actually a Pontiac, and is NOT the GM 153 Iron Duke that is used in Marine outdrives. The original Iron Duke was a Chevy II engine, based on the early stovebolt 6 design.    Back to the drawing board guys, there are no off the shelf marine manifolds for the 151. 

i don't want a marine manifold, in my opinion they are not efficient enough,
all they were made to do was cool the exhaust enough to keep the boat safe from fire hazards

bob g

The Iron Duke was used in boats they used a different cam than an auto but they were the same block I know of more than one that has been used out of boats and the other way.Tom T

Another engine that is often overlooked is the Engine 2.3 four cylinder engine that is used in the 240 Volvo.It is the B230F. My wife and I both have 1993 240 Volvo's and they have been the most reliable cars period.
My sedan has over 286,000 miles and my wifes wagon has over 310,000 miles. Both engines have lots of life left. These engines have been known to last 600,000 miles. The reason the engines last so long is the high nickel content in the block and the oiling system. The compression ratio is 9.8 to 1 so this might be a good engine for LP and natural gas for engines in the 2.3 L. class. another thing is there is lots of them becoming available in the bone yards. They are a very easy engine to work on also. Another thing is the timing belts last a long time I replaced my wifes belt over 170,000 miles ago and it only takes 30 min. to replace. If the timing belt ever breaks the valve train will not get wiped out because it is a free running engine design. This engine has a taller deck height than most compareable engines and the crank to rod angle is also better than most. This will mean longer burn time near TDC than some engines well known engines. These engines never needed an EGR valve to pass emissions so the only smog control was a catalist. They were pretty clean and efficent running engines.

Henry

Natural gas is 130 octane, I just checked. Wow! We can push the comp way beyond propane engine territory here.

The ideal donor engine will be something small that had some aftermarket racing support at one time, and cheap and common.  But better if it has small displacement, so we can get better control on the rpm. Even better if hydraulic lifters and pushrods   Cross flow design preferred for ease of getting at the exhaust manifold to build a heatex. Anything that had or has a any use in a racing class that will give us access to the high top pistons that we will need to make an efficient engine on NG.  130 octane should support 13 to one compression ratio easily.

Datsun in the 60's and 70's had a little pushrod job that was based on a British design. Used in 60's trucks, Datsun 1000,, Datsun 1200,   B210 . That was a good little engine, very tiny in size too. Still in production as an industrial engine. Might be a good prospect.

That Datsun/Nissan pushrod Austin designed engine was built up to 2009 over seas. I know lots about that nice engine. I built one engine using Nissan performance parts I purchased from Bob Sharp Racing back in the early 80's. Any one that wants a 9000 RPM screamer pushrod 1400 cc engine that is a good one to start out with. The engine had to be wound up to 5500 to get the car moving. ;D

Even stock they lacked torque.

Henry

http://www.datsunhistory.com/Sharp.html

I did meet Paul Newman and talked briefly. He was a very down to earth guy. He brought a lot to racing and he is missed.

Henry

The Datsun engine is the about the same as used in the MG I know the rocker shafts and some other parts will interchange not sure about all parts but the shafts will.It started out as a tractor engine.  Tom T

I rebuilt one in a 66 truck for my buddy in about 84 , it was 3 main bearing design. Datsun dealer wasn't any help so I crossed over the pistons and rings from a Spitfire. That's how I know it's really a british engine. By the way that truck had crank start and was super easy to hand start. Now that might be useful!

There's one on ebay right now, they always turn up in power sweepers,, or apu's for tour buses, always   on propane.  Just search propane engine, there's usually at least 1 nissan 1A on offer

the volvo looks good

so does the mercury topaz 2.3hso engine

http://www.tempotopaz.com/main/index.php?name=Sections&req=viewarticle&artid=35&page=1

iron head, pushrod enigne, looks like a contender to me
they seem to be readily available and don't bring much likely because no one in their right mind is going to repower
a 20 year old dead topaz.

having both manifolds on the same side is a minor issue

there is one here in tacoma for 250 bucks with 46k miles, i think i will go have a look at it.

it looks like the 88-91 engine's had their peak torque at 2200rpm, that makes it close enough for a direct drive generator application.

bob g

Quote from: mobile_bob on December 19, 2010, 08:45:14 PM
they seem to be readily available and don't bring much likely because no one in their right mind is going to repower a 20 year old dead topaz.

You haven't met my russian neighbor. ;D I still haven't ruled out removing 4 pistons from the old 350 I have in the corner... ::)

How does increasing the compression ratio effect the overall durability of the engine? I would think low compression engines would be under less stress and therefore last longer...then again diesel engines kinda blow that theory away. I wonder why the Olympian 2.4L LP/NG generator I posted only has 8.5:1 compression?

Let's get one thing straight here though: There is only one Iron Duke. That's the 151 Pontiac. All the 'others' are just random chevy motors that have similar displacements. I don't think any of the others are cross flow.

Edit: I just looked up the specs on the Mercruiser 3.0L engine, which I think is based on the iron duke but never used in cars. They list a 4" bore by 3.6" stroke with 9.1 compression...looks like a stroked 2.5. More torque....

Another consideration might be the AMC/Jeep 2.5L engine. It's basically a shortened Jeep 4.0L, which is known for it's amazing reliability and tractor like qualities. 3.875 bore by 3.1875 stroke makes more torque than the Iron Duke, and it's got the same bellhousing. Both the iron duke and the AMC 2.5 have five main bearings.
http://en.wikipedia.org/wiki/AMC_Straight-4_engine

I have an old Cherokee with the 4L inline six version and it's only parked because the CPS sensor went out at 230k. Everything else is original. If I averaged 35mph, that's just over 6500 hours, though I'm sure it's much higher than that.(and I'm certain I could double that with a new CPS) My cousin has one that she's wrecked 3 times and the engine is still going past 300k. I wrecked one myself and pushed the engine back about 3 inches into the firewall. It was still running, though spewing coolant, ATF, oil, and freon. I still remember having to climb back in the wreckage and pull out the key. :D 24mpg on the highway in an automatic 3500lb vehicle with the aerodynamics of a barn and the A/C on. You guys are making me want to convert my old Jeep to propane....

Quote from: mobile_bob on December 19, 2010, 08:45:14 PM
the volvo looks good

so does the mercury topaz 2.3hso engine

http://www.tempotopaz.com/main/index.php?name=Sections&req=viewarticle&artid=35&page=1

iron head, pushrod enigne, looks like a contender to me
they seem to be readily available and don't bring much likely because no one in their right mind is going to repower
a 20 year old dead topaz.

having both manifolds on the same side is a minor issue

there is one here in tacoma for 250 bucks with 46k miles, i think i will go have a look at it.

it looks like the 88-91 engine's had their peak torque at 2200rpm, that makes it close enough for a direct drive generator application.

bob g

The mercury topaz 2.3 HSO might look like a nice engine but they are known to crack heads. And I am talking about more than a few. We had a company car that cracked a head. and it took three trips to the bone yard to find a good one. They crack in the exhaust valve seat and up in the exhaust port. Not a very reliable engine in my opinion.

Henry

Quote from: TimSR2 on December 19, 2010, 05:52:13 PM
I rebuilt one in a 66 truck for my buddy in about 84 , it was 3 main bearing design. Datsun dealer wasn't any help so I crossed over the pistons and rings from a Spitfire. That's how I know it's really a british engine. By the way that truck had crank start and was super easy to hand start. Now that might be useful!

There's one on ebay right now, they always turn up in power sweepers,, or apu's for tour buses, always   on propane.  Just search propane engine, there's usually at least 1 nissan 1A on offer

That engine was and early version. They all changed to a 5 main block after that.

Henry

after doing a bit of research it appears the 2.3hsc engine's did have some issues with cracked heads
the reasoning is that the induction hardening of the exhaust seat area places significant stress in that area.

might be best to have the head reworked and fitted for hard seats, cutting out the induction hardened area
ought to remove the culprit.

also i am not sure if it is a problem with all the years that this engine was available?

from what i can tell the base engine's if you have a good one, and maintain it well will make 300-400kmiles which is good
and as i suspected they are about worthless as they aren't worth the effort for the yards to pull them because the cars are of
no real value that they go in.  so they don't pull many unless they check out as being good ones.

from the topaz/tempo forums, it appears one should not give much for these engine's because they just aren't worth much
one guy suggests good ones should be in the 200 dollar range, and certainly never as much as 500bucks.

i think i will still go have a look at the local engine, it is pulled on in their warehouse so i can at least get a good look at
what it looks like it would be to use it for our application.

maybe if it looks good, and worth messing with i will offer him a couple hundred and see if he takes it, then see how it works out.

it might be that because the cogen application only requires 1800rpm, and less than 12kwe with a good cooling system, it won't be under a lot of stress
and be ok? 

just because the have a history of cracking heads does not mean they all cracked

from another head repair site, apparently the late model dodge 318, the 87 and up vortec chevy, the iron duke and a few others also have a history of cracking heads, and we know they didn't all crack.

point is "if" the engine fits the need, is easy to work with and can be found with low miles and in good condition for ~250 bucks or less, i think it might be a decent platform to develop into a cogen.

if it works i think i will start collecting them as they come up.

as i see it the engine needs to be relatively cheap to start with, widely available, reliable, and simple to work with. i think apart from the head issues this engine fills the bill nicely.

the only other one i like is the volvo engine, and i might look into that one as well.

ideally we could come up with a platform to develop all the ancillary bits and pieces for, things like engine mounts, generator drive components, pumps, heat exchangers that are optimized for the specific output of the engine, etc.

the one thing that the lister/oid and the chanfa/oids have in spades is a certain level of consistency where if someone develops a part and finds it to be a good fit, it will not only fit his but every other lister/changfa on the planet.

going to be hard to do with gas engine's unless we boil down the jillions of possibles to perhaps a couple base engines.

bob g

On reflection,

I think that the idea of a lightly loaded ng chp should  for household purposes be much, much smaller than what we have been discussing, like a  24 or 48 v dc generator  used with an inverter  and battery bank. DC alternators would allow us to run any rpm.   Autostart on low battery signal from the inverter or low temp when there is a 'call for heat' from the heat system.  We should be avoiding continuous runs like a storebought generator and moving toward a demand system.

A system designed around a small currently available industrial watercooled  engine,run at low load and medium rpm , on natural gas,  with storage batteries, hot water storage, autothrottle and a reasonably sized inverter..., say a 3 kw Grid tied?  Built into a small package with boiler heat interface controls and autostart. That would be impressive.

i am thinking a step ahead of you on this one

if the unit is running it should be only when there are sufficient scheduled heavy loads to be serviced, therefore 1800rpm 60hz operation,
while this is taking place additional alternator(s) to provide for direct battery charging, and a differential governor so that it only runs at 1800rpm
if there is a load that needs serviced, otherwise it could drop to something more economical like perhaps 1000rpm.

having the ability to also drive an A/C compressor for refrigeration loads would also be of a benefit so that any combination of loads could be serviced
at either 1000rpm or 18000rpm and optimize the load on the cogen

an ideal control system would sense and evaluate all of the load demands and make the appropriate setups, start and service those loads in the most efficient manner
and then shutdown the cogen, poll for data and restart when programmed conditions are met.

with nat gas currently priced at about 1.04 per gas gallon equivalent, the unit could be fueled for about 1/3 the cost of pump diesel.

and if we use some sort of control scheme that limits the run time to optimize the overall system, the cost of operation gets cheap enough to not want to mess with burning waste oils once one factors in the true real costs of those waste fuels.

imho

bob g

Quote from: TimSR2 on December 20, 2010, 08:05:32 PM
A system designed around a small currently available industrial watercooled  engine

Such as? I think one of Bob's best points here is this machine can be made from junkyard automobile parts, thus they are much more common and easier to find, and I would guess that I could buy a 4 banger car engine for cheaper than a two banger 'industrial' engine. That's the whole problem with small water cooled diesels, they are almost non existant unless you're rich or you happen to get your hands on a foreign copy, and that's only getting harder and harder. With an iron duke, on the other hand, I would bet you can get most parts from a GM dealer...

As someone noted above even if you only want two cylinders it might be easier to start with a 4 cylinder and take two of the pistons out. I still think a target of around 1200-1500 RPM would be good, with a belt drive.

My opinion is that the Ford 2.0 and 2.3 cast iron I-4 engines are hard to beat. I had one in a '74 Mustang II and have on now in the '92 Ranger 4X4. The first engine was a carbed job whereas the last is am injected version. The carbed version was far more powerful than the truck motor, but both were/are bullet proof. My truck engine has 234 K on it and still runs fairly good. The compression is down, but that is just old rings. "Racer Walsh (http://racerwalsh.zoovy.com/c=3C7ZQPQTGRVbJJMTkWsRP4bzD/category/4cylinder/)" has performance parts of all sorts. Ford built a version of this motor with a turbo they put in T-birds and some Mustangs. They have a flow through head with intake in one side and exhaust on the other. I'm pretty sure Ford made a diesel version of this engine.

R

The 2.3 engine in the turbo mustang and thunderbird are known to crack heads. There are other places to purchase performance parts cheaper than from Racer Walsh. I used to purchase loads of parts from them when they were up north when I was building ford drag boat engines. The 2.3 OHC is a good engine as long as you have a good head. talking about a 2.3 diesel in a Ranger, Don't even think of getting one of those!!! They blow up. And they are made by Mitsubishi and they are total junk. one of the worst engines Ford ever used.

This is why I like the B230F engine from Volvo so much. They are easy to find. They do not crack heads. they do not have all the smog junk on them. They have a taller deck block than the Ford 2.3 OHC. They already have 9.8 to 1 compression. they can be dialed in for what you want. They can be built up to have 11 to 1 Compression with just pistons if you want. The engines hold up to well over 500 hp. One of the easiest engines to work on. And have been known to last 600,000 miles.

Henry

One thing for some of you to explore is if your local power company offers a "time of use" billing plan. I'm switching over to this now, I used to pay $0.10/KWH 24/7, now I'm going to be paying about $0.125/KWH during peak hours and only 4.5 cents "off peak".

Basically my NG generator will run during the peak electrical price period, and store enough heat for 24 hours.

Quote from: Jens on December 22, 2010, 07:33:32 PM
Would battery storage of energy be economically feasible with that kind of a cost discrepancy ?

I've thought about it, hard to say really when you add in the cost of the batteries. Batteries aren't as fun to play with as engines. ;D

i figure that if i can get a 2.5 cent spread, it is enough to cover the depreciation on a set of batteries

actually anything over 2 cents/kw/hr spread will cover the depreciation on most batteries.

i hadn't looked into the time of use plans, and i am not sure they are available in the small town i am moving to.

however i have looked at the different rates between commercial and residential natural gas, with commercial being about a third less than
residential, so maybe i can get that rate if i setup a business on the same property and put the cogen between the house and the shop?

;)

also am looking into the rates for bulk cng to see how that might compare, having the bulk tank allows for buying off season when rates are lowest
that might be something that makes economic sense as well.

now if i can get the electric company to buy back at parity any power i can produce, that would eliminate the need for batteries all together.

bob g

Quote from: mobile_bob on December 22, 2010, 10:33:56 PM
also am looking into the rates for bulk cng to see how that might compare, having the bulk tank allows for buying off season when rates are lowest
that might be something that makes economic sense as well.

Wow, I didn't realize that was possible. Just how big a 'tank' are we talking and how much do those run? I want to setup my cogen so that it will run from NG or propane, having propane as the stored backup fuel.

I have *BRIEFLY* looked into cogeneration on an industrial scale...that is, start my own "power company" that sells electricity AND heat to the neighbors. I seem to remember bulk NG being only around $0.60/therm...except there was like a $500 monthly 'basic' charge. I've even considered partnering with the city sewer system for a source of "methane"....

I know this is off topic for this thread but with "exploring another option" I thought I would post anyway somewhere and this seemed to be the best option without starting a new thread.
My question is Does someone have a refference for SAE bellhousings and all that goes with it? IE a new idea is to get some junked engines for co gen. The Iron Duke and others. I can speak for the ole Volvo four banger that was in the 122, P1800 and was used for I/O stern drives. The engine is bullet proof if there ever was one.
So say I have one of these engines and want to driect drive it to a single bearing ST or other gen head. How do I figure out what I need. I know I need some sort of bell housing to fit between the engine and the gen. An adaptor plate that looks something like a clutch plate, but bolts onto the flywheel of the engine. It has some "Springs" similar to what is on a clutch plate and the gen head slides into it similar to what a gear box would do. So how do I figure out what to order? I think the whole confirguration is governed by SAE code/guideline or what ever. I think this would be a good reference for all of us.
"Who moved my cheese" GREAT book we should all read and if we have read it read it again.

Chris

Here's a thought...could you make an engine run on alcohol and/or natural gas? In the summer time you could use your waste heat to make your own moonshine. (denatured, of course ;) ) Use waste products like bad fruit as a feed stock.

http://cgi.ebay.com/Lister-HR2-G-Industrial-Natural-Gas-Engine-Cores-/180448183293?pt=LH_DefaultDomain_0&hash=item2a038cc3fd#ht_500wt_1156

Lister HR2-G Industrial Natural Gas Engine Cores

How about this for a starting point?  With an air to water heat exchanger for the cogen, should be easy as these have very powerful cooling fans

What do you guys think about running an inline six engine on three cylinders, with the other 3 pistons and pushrods removed? The Jeep 4.0L would make a great candidate, it has the same bore as the 2.5L with a longer stroke. 3 cylinders would give you a roughly 100hp, 2 liter engine with seven main bearings, and, if you ever need to do a rebuild, you still have 3 cylinders that you haven't been using! I wonder how smooth it would run?
http://en.wikipedia.org/wiki/AMC_Straight-6_engine#4.0
Not a cross flow head, but I tihnk some of the Ford sixes were? The first thing a 4.0L Jeep owner will tell you is how reliable it is.

Jeep 4.0 HO

An awesome all cast iron engine, with quite high compression, and  super common.  They are derived from  the Rambler 232, through the 258 Gremlin/Jeep engine,  and share cylinder head and port designs with the 2.5 liter 4.   They are unbelievably tough  ( I own one for the last 8 years, my wife's daily driver) Torque peak is about 1500 rpm .

But.... they are huge!  Great engine for building a chp  greenhouse operation off grid in the PNW... but way  too big for a house.  And we still have the problem of rpm control, unless we can adapt a governor system, hack into the ECM or go with alternator/battery/inverter system.

If we were talking about building a 30 kw 1800 rpm NG genset it would be top of the list.  But ike so many prospects the jeep 4.0 is way too large for a house size chp project. Now if we could cut off the back 4 cylinders and close up the block and head and get the flywheel back onto the crank, then maybe we'd have a winner. 

Quote from: TimSR2 on December 25, 2010, 10:41:01 PM
But.... they are huge!

How much do listers weigh again? ;) Take out half the pistons and it's smaller than an iron duke, with a lower torque peak, and more of it. I just wonder if it would run smooth enough? My guess is that it would run quite stable at 1200-1500 RPM with no real need for 1800 direct drive.

removing pistons is not a straight forward proposition, most especially for an inline 6 engine

1. you have balance issues, to contend with

2. you have extreme torsional issues to contend and overcome, otherwise a broken crank will result

3.  you have oiling issues, the crank will bleed off oil pressure through the big end holes, and

4. you will have issues with simply removing the rockers, and pushrod, because the lifters will need to be
retained in order to maintain the oil system integrity

and likely a few other issues as well will come up, some of these and others can be worked around fairly easily while others not so
easy.

for my money, either find a suitable small engine to start with, or cycle the larger engine so that it matches the loads both thermally and electrically
this will likely require some form of battery storage or grid tie, or a rather elaborate management scheme with combination of one or the other.

screwing around with taking out cylinders from an inline 6 or even a v8 is just asking for problems, lots of problems.

other possible problems are ignition related, with crossover arcing because of vacant holes, burnt out distributor caps and rotors (yes this happens if you run
the chevy vortec with a dead hole for any length of time, and can't imagine it would get better with multiple dead holes) coolant flow issues, are likely also to be a problem, with half the engine being cold and the other half hot?

while it is fun to speculate on what is possible, i think it would be more fruitful to work with what is known to work as is, a cogen project that is most successful
is a big enough hurdle to engineer and integrate effectively, without the added layers of complications brought on by trying to alter an engine to run on
half of its cylinders.

my opinion only of course.

bob g

Quote from: Jens on December 26, 2010, 12:49:54 AM
The bottom line - you are right, it's much easier to start with an engine that matches for the task at hand.

The problem is there is no such thing. Period. Any engine being discussed for this purpose is going to have to be completely built for this purpose. Nothing will be stock about your engine. If I could buy a water cooled, iron, industrial 2 cylinder high compression NG engine with a built in governor, then I'll take one. I don't think it exists...and even if it did parts would be harder to find than anything automotive. (actually something like an Arrow engine would be absolutely ideal for this purpose, but I don't think any of us can afford one)

The only issue I see with killing cylinders is the engine balance. Sorry bob, but a lot of your concerns are unfounded. Air compressors made from half of a Ford V8 are as common as dirt. They run fantastic on 4 cylinders while pumping with the other 4. The engine would only run smoother with pistons removed. We are talking about an 1800 RPM or less red line. Balance might be an issue, but not one that can't be fixed. I don't see why cooling would be a problem, water would still be circulated through the entire engine block. I used to have an old truck with a 454 that was only firing on 7 cylinders...I drove it more than 10,000 miles like that. I didn't even know at first, and have no idea how long it had been running that way. I took out the spark plug to kill the compression in that cylinder after a while.

It really depends on which engine you're trying to kill cylinders on, and which cylinders. Maybe killing half a V8 would work, but half an inline six won't? I'm not sure, but you also have the choice of removing 3 pistons in a row or just every other one. Or maybe killing half of a four banger would give better balance. Sure, it will take some fiddling around to get it right, and it might not work at all...but that can be said about everything we ever talk about on this board. The commercial availability of "multi displacement" engines in cars seems to suggest there isn't a problem with stress on the crank...especially with seven mains. I also find it interesting that most of the 4 cylinder engines talked about so far, are made from either six or eight cylinder engines cut short at the factory.

If you want 'off the shelf', you need to spend about $100k on a microturbine. Otherwise it's going to be a completely homemade machine with a very custom, one off engine. Just the fact that you need to bump up the compression means you'll have to tear the engine apart and do a custom build if you want efficiency.

Hell, who's to say six cylinders is too many anyway? Take a look at what Arrow has to offer...
http://www.arrowengine.com/products/Multi_Cylinder/VR_Series.php
The VR330 is a 330 CI inline six. It's rated at 26 HP at just 900 RPM, designed for natural gas.

Some quick fuel calculations show it's about as efficient as any other NG generator...
http://www.arrowengine.com/Tools/fuelconsumption.asp?engine=VR-330

Too bad I'm guessing they cost more than my house...

A bit more research shows inline six engines to be inherently balanced, because the crank throws are 120 degrees apart and the front and back pistons move in pairs. This means killing every other cylinder would result in an engine that is still rotationally balanced, but tends to rock front to back more than a six. This could be a problem in a car at 5000 RPMs, but probably not when mounted to concrete at 1200 RPM.

I'm starting to think an inline 3 would be the best option, whether you 'make' one or buy one that was built that way. Four is more than you need, 2 isn't enough...3 balances nicely. A 60 degree V6 running one bank of cylinders could be another option. The extra weight and length of the inline six would help dampen some of the vibration a factory built inline 3 might see.

I'm not "allowed" to spin my meter backwards with an engine, thus without a significant investment in batteries and inverters, an oversized unit would be of little use. If I could just fire the engine up long enough to spin the meter to zero I'd use a huge one...but that won't fly with my power company.

I welcome anyone to poke holes in my theory...but I think inline sixes are more common in junk yards than inline threes, and I still like the idea of having 3 spare cylinders you can use later. You could theoretically seize a cylinder or two (been there) and have the engine up and running again the next day without machine work.

let me explain my rationale further

the reason aircompressor conversions work is they retain the rotating components, right down to the use of a modified cam and lifters

without the use of the lifters you will lose all your oil pressure, because of the way an engine's oil system is typically routed.


while i would prefer a 3 cylinder over a 4 cylinder, i would also have to agree that there are precious few 3 cylinders to choose from.

your report of driving an old chevy 10k miles with one plug removed is something i too have had to do in the past, however it doesn't have much
that applies here, in that the rotating assembly is still intact and the lifters are still in place.  my experience was with a 7 cylinder ford 460 and i suspect
yours was an older and not the newer version of the hei ignition, which is likely what we will be needing to work with when it comes to high compression
ratio's if we want to go that route.   the new caps and rotors will crossfire and they will burn out the caps internal traces killing cylinders in operation.
we can probably get around this issue with some work, but why do we have too?

another issue, is one of efficiency,  we can harness up to about 90% max, the remaining 10% is radiated from the block, if we use half a 6cylinder we just doubled those radiant losses,  allowing us a new ceiling of about 80% max.

i will also say this, i don't want to discourage anyone from doing whatever it is that they want to do, however i would be remiss if i didn't voice my objections
if i felt there were problems with the route proposed, leaving a forum member or someone with the possible outcome less than what it could be, or worse a failure due to some problem like a broken crank, or continual ignition issues, or something else.

youj are also correct in the assertion that there is no one engine that is good for everyone, as there is no way to satisfy everyone's needs, let alone their wants.

although i would say that meeting the real needs of a large percentage of folks could be done more easily with a 4 banger, than would be the case with just about any other engine i can think of that is readily available.

lets also talk about efficiency a bit more, as it relates to the cost of this sort of project

we really don't need to spend a fortune making the perfectly optimized engine, because we are not needing to match the mechanical efficiency of any other engine like the arrow or some others, because what fuel that is burned to make mechanical power is only part of the overall target.

so long as the engine is good enough to burn relatively cleanly, i don't care if it is 20% efficient or 30% efficient mechanically, because the balance of the fuel burned will be recovered as waste heat,  that is the beauty of cogen.  depending on what one needs from a cogen, or rather what his focus is, electrical or heat
will determine how efficient the engine really needs to be.

i would assert one needs to look at the engine more as a furnace than a producer of electrical power, mainly because it is about 3x better at making heat than it ever will be at making electricity.

i would also assert that we would have a higher degree of the expectation of success if we choose an engine wisely and use it as it was designed to be used, or as close to that as possible, and not start off with having to heavily modify the engine.

and there is no way i wanna bolt the engine down to a ton of concrete to tame any issues with balance or vibration, an automotive engine was never designed to tolerate those stresses and i would bet my last dollar that anyone that does this sort of thing will be met with much disappointment.

again these are just my opinions, don't let me be a wet blanket
if you are sure of the outcome, and have the time and money to do it, go for it.

i hope you are right, i hope it works out well.
because if you are right, there will be many more options at a time when our options are few.

bob g

Interesting topic guys.
In my humble opinion good engine usability begins at a 90 degree V-Twin. Still got 9 working vertical and horizontal single cyinders I use to prove this point. Yes a watercooled 90 degree V-Twin is a new production rarity - but Kawasaki's and Kohler's are out there.
I have two inline 3 cylinder diesels in my life and have had a few Suzuki/GM Sprint/Metro's too. GM insisted on 3 cylinders versus the  Suzuki four cylinders to get the ~15-20 real world efficiency savings from less ring and bearing drag. I have yet to be able to get ANY of these inline 3 cylinders to run on two cylinders.
But my favorite and most used lifetime engine is the watercooled 4 cylinder. I've not yet had an inline 4 cylinder I could not get useable power out with one dead cylinder and only running on 3 cylinders. I've been from 1098 cc's to 2700 cc's on these - best inherent balance is in the 1600-2000 cc range.
No reason with a gaseous fuel to be so picky on engine choice. Use what you've got or use what is common and cheap around you. Even as much as I've learned to hate timing belts especially when as on the newer engines they insist on water pump driving with these (kills the bearings) one of the reasons for the no push rods/overhead cam design was to allow larger in and out gasses flowing valve porting.
Look here at what can be done:
http://www.youtube.com/watch?v=wKMlCqkloF4
DANIEL, woodgas fueling a Toyota OHC 22R 4 cylinder engine belt driving a 3 phase motor for 240 volts 69 amps (16.6 kw).
I have no Grid tie possiblilities or desire so would just go with as small of 4 cylinder as possible.

Regards
Steve Unruh

I don't know anything about this topic, so don't beat me up too much.   Biohazard gave a link to the Arrow engines.   I notice they have single cylinder oil-field engines w/ huge flywheels and rate below 10 hp @ 400-800 rpm.   Looks like a modern-day gaseous lister.   Appears perfect for woodgas, NG, LPG....   Are they just really expensive?   

i would be shocked if you could by any of the arrow engines, even the singles, new for much less than 10 grand

however i haven't check into one in a very long time.


going back to the cutting off half of an inline 6 cylinder or half of a v8
to what end?

we can get 4 cylinder engines fairly easily between about 1.3 to 3 liters just about anywhere.

the reason i like the pushrod engine's is based on their ability to make more bottom end torque
where generally the overhead cam style, requires much more rpm to get into the gains made possible by this design.

the former statement of course is a general one, and this is not by any means all inclusive.

as for comp ratio, i don't see the need to go over what is commonly available, with engine's available with 9:1 that is good enough
by me, and likely would present fewer problems down the road than one optimized for natural gas running 15:1 ratio.

with some of the enigne's available with low miles from the bigger salvage yards  for ~300 bucks, why not just use em like the top fuel boys
did with the hemi's in the 50's,,, where they pulled salvage  engines on monday-thursday , then mounted them with blowers and nitro on friday, saturday
and ran them till they puked, and went and got another one.

granted they might only have gotten a few runs out of a junkyard engine, however i don't think we will be asking the same sort of performance as don garlits did back in the day.

it lust seems right to use what is widely available, relatively inexpensive, and readily adaptable to our application, that way more of us can work with a specific engine, or family of engine's, leaving us the ability to develop all the ancillary parts without having to reinvent all the varied wheels  involved.

if that makes sense?

what i am not suggesting is going out and buying an engine if you already have an engine such as an inline 6 you want to remove cylinders from, or alter in some way,, however if you are faced with going out and buying an engine, why buy one that needs anymore alteration than is necessary?

bob g

Why are you guys beating your heads against the wall?
ONAN made tons of these engines. Lots of boats had water cooled MCCK 6.5 gensets. 1800 RPM.
I have a few CCK air cooled units, in 4 Kw and 5 Kw.
MCCK engines are higher Kw rated than the air cooled ones because they can carry away more heat.
They are sized right for house hold Co-Gen.
I'm having a hard time finding the high compression heads, but a web ad for them has a nice picture and CC volume, so I can weld in and mill a standard set to get the compression ratio up. (from 5.5:1 to 7:1)
with a condensing exhaust heat recovery system, total power plant efficiency will be over 90%, heck you could get an EnergyStar rating!!
My house has an oil fired hydronic heat system. It has an old Crane 'Sunny Day' cast iron sectional header boiler. I'm going to change it out for a natural gas boiler. The Zone Control heat system has the possibility of back feeding heat from the Co-Generator, so even if it doesn't add enough heat to the house, the boiler could fire and supply the remainder.
Although we get several power outages per year, the natural gas has never had a failure in over 50 years. My son Peter completed his Natural Gas powered back up generator last week. It's an ancient ONAN 705CW 7.5 Kw plant, an opposed twin like the later models, but with removable cylinders (!) It carried the whole house and shop with ease. No fuel tanks, no mess, no smell, and with the motorcycle muffler, very quiet (out side).  ;)

Don't get the wrong idea bob...I'm not trying to fight, like I said, feel free to poke holes in my theories. That's why I post them here first. ;) As for mechanical efficiency, I want as many kilowatts as I can squeeze out of a therm of gas - because I have a much greater need for electricity than heat.

Quote from: mbryner on December 26, 2010, 10:14:57 AM
Are they just really expensive?  

That would be an understatement. Search "Arrow engine" on ebay.

Quote from: SHIPCHIEF on December 26, 2010, 11:22:58 AM
Why are you guys beating your heads against the wall?
ONAN made tons of these engines. Lots of boats had water cooled MCCK 6.5 gensets. 1800 RPM.

That would be great, if I can find a junkyard that has a pile of them out back for $300 each. I have been looking on ebay and craigslist for just one, and have yet to find it. Parts? I'm sure many can be ordered from the internet...but for how much longer?

I'm sorry but I just don't think ANY other engine MFG can compete with GM or Ford for engine and parts availability, prices, and long term support...

What we're looking for is the "350 Chevy" of cogenerators. The 350 has been in continuous production since 1955, all around the world. Parts are available in any country for peanuts. The engine has been used in everything from cars and trucks to boats and planes and even generators and other industrial uses. It's just too big for what most of us need...

I've really been studying the Arrow 4 and 6 cylinder engines and I wish I could afford one. That will never happen. I can however copy it.  ;) Their literature is an interesting read for a generator geek. Something noteable, the 4 cylinder engine comes with an optional balance shaft that "greatly reduces vibration", while the inline six does not get the balance shaft because it doesn't need it. (their 4 cylinder is 4.2 liters) About the only thing I can't copy are their wet cylinder liners, but I don't see that as being very important. For a governor they use either a mechanical unit gear driven off the front of the engine, or newer models come with an electronic version. I like their CDI distributorless ignition system. They also have a newer cross flow head for their engines, which claims a 6-8% increase in efficiency over the older head. Most of that stuff could be fitted to an iron duke.

http://www.arrowengine.com/Literature/VR_Series.php

Inline six would be overkill for most houses but it's probably the smoothest running/longest lasting engine you'll find. I think it might be the right size for the new shop I'm planning. My boat has a 1.6L inline six, too bad it's a 2 stroke, that would be great in a 4 stroke.

Maybe I'm overcomplicating things, but you're talking to a guy who cleaned and sorted 50 tons of gravel by hand for a barn floor...because it was too dirty. ;)

Bio

i don't think you are over complicating things at all, as a matter of fact having this discussion likely will work out at least some of the
kinks and at least lead us to what likely will be the best group of alternative engines for this use.

otherwise we end up using what we got, and maybe that won't be the best use of our time and resources.

i have found this to sadly be  on of lifes truths, often times when i try to use what i have and get in a hurry, the end result is somewhat less than
what i had hoped for.

then when i look back that part that i had on hand that saved me 300 bucks in first cost, turned out to cost me many times that in the end
and then even more over the life of the finished product due to lower efficiencies and other problems.

i guess what i am saying is, one would hopefully gather from discussions like this one that perhaps he might be better served to use an iron duke
rather than a pristine vega motor he either has or can pickup for free from a buddy down the street.  i know this is an extreme example, but i think it
illustrates the point.

even if we conclude from this discussion or another , that perhaps removing rods/pistons to reduce displacement as being not the direction to go, perhaps
we still learn something from the discussion that might be useful somewhere else down the road.

besides i don't think anyone can be anymore "anal retentive" than i am.

:)

for me at least i think i have boiled it down to the following engines

the iron duke, the volvo, or perhaps the topaz/tempo 2.3 from the automotive world, each has its strong points i guess.

i am also considering putting in a coin op laundermat on the opposite corner of my property, laundramats are useful in town and there no longer is
one in the little town i am relocating to. this would do two things for me,

1. i could get commercial nat gas rates, which cuts the cost ~30%

2. laundermats need lots of hot water,

3. the waste electricity could be moved over to my house for direct use.

4. i might even make a couple dollars off the laundermat from normal operations?

that was one thought anyway.

another was building perhaps a 6 plex housing project of high efficiency units, where i could rent them and include the utilities,
and balance the demand between the cogen and the utility company.

i think there would be enough heat load year around to supply me with paid for electricity as a waste product of the system, certainly
in the winter months this would be so, and the cost of rent includes the cost of the nat gas anyway,, and i am not sure but i might also
qualify for commercial rates.

another alternative is the shop idea like you have,
if i put in a repair shop it can probably pay for the cogen operation and i can borrow some of the work products for the house
and have the shop/business write off the cost.  this is a little sticky, but if setup right probably could be done in an irs friendly manner.

in the end however in my opinion the holy grail will be a continuous operation absorption chiller that can provide A/C from the waste heat
of the cogen, that would make the unit vastly more efficient over the balance of the year where cooling is needed more so than heat.
if we ever get there, then we have really arrived in my opinion.

bob g

A gas turbine? ;D http://cgi.ebay.com/TURBINE-GAS-ENGINE-GENERATOR-SET-/200436078003?pt=BI_Generators&hash=item2eaaebd5b3

What kind of fuel can a gas turbine be run on?

Quote from: rl71459 on December 28, 2010, 01:51:16 PM
What kind of fuel can a gas turbine be run on?

Jet-A, Jet-B, kerosene, pump diesel, home heating oil thinned with kerosene.

For what we would use it for it would not be practical. The only way you will get any effency out of it the unit has to be ran at full 100% output at all times.

And if you think Diesel engines are expensive to rebuild. You will have to get a second mortgage to rebuild this puppy. And to run it you better have deep pockets.

Henry

And deal with complaints from neighbors about the noise!

I like this "my generator is too big, what else can I hook it up to?" mentality. ;D At this point turning hot to cold would be like turning lead to gold. I'm pretty sure I've seen waste oil fired commercial A/C units somewhere...maybe that would be a start.

Sometimes I wonder how the neighbors would react if I tried to sell excess heat/cooling/electricity to them. I'd love to be the neighborhood utility company. They already think I'm crazy enough though. I guess there are worse things a guy could do with his free time... ::)

Random thoughts regarding this thread....     Of course we are all trying to reinvent the wheel here as others have stated. There are great old technology units on offer cheap.....Shipchief has noted the Onans from old motor homes, or pleasure craft are quite heavily built, and I must agree. If MCCK's could be found from fresh water environments and the heads planed a bit... they would be excellent dry gas engines. But Onan parts are expensive, even more than English Listers.

There are also the Honda watercooled motorhome sets....  Expensive, but  long lived. I've seen 5000 hour units in mobile kitchens that are still running well.

But do we really want to put all our eggs in one basket ? We want more heat than power here, right? Let's think like a power engineer for a minute .  In a large boiler installation if the 'call for heat' exceeds the supply they just bring another boiler online. So maybe two or three tiny engines could fill our requirements?  2 , 3, or 4 easily replaceable, drop in units, that can be swapped out quickly with spares.  Units that will synchronize their electrical production with each other automatically......

What about Honda EU1000's, or even EU2000's?  They are reasonably priced, standardized, can synchronize with each other, and are common as dirt. We only have to build a rack to mount them in,  and an air to air,  (this is off the shelf; it's called an air exchanger, my house has one)  or air to water heat exchange system. Easy tri fuel conversions available, also off the shelf.  We could have complete generator units stocked in case of failures, rotate the units for service, and to keep the hours distributed evenly .

Standardization, compact size, reliability, inverter built in..  90% of the engineering already done for us...   All we have to do is get over our water cooling bias  here  and engineer a heat exchanger solution to suit the base module.  My preference would be the EU1000.

we certainly have kicked several idea's all over the parking lot with this discussion, however my original thought was more inline with
trying to agree to a common platform  that several folks could work with to develop the ancillary parts that are needed to make a cogen unit.

i guess the problem will always come down to choice of fuel, sizing issues, and personal preferences to some degree or other.

for me at least, i have been kicking this idea around for some time, while i may still build up a cogen power by a 4banger fueled by nat gas, it would probably
be more for the R&D experience, but more likely would only be used intermittently or during times of the year that it can be used to best effect.

at the end of the day, sticking with the s195 changfa and simply dual fueling it with nat gas makes probably more sense, would be far simpler and could seamlessly  change from diesel only operation to dual fuel without any changes to the engine.

the changfa is sized most appropriately for my end use, in that it could be ran over a longer period of the year at max efficiency than would a 4 cylinder driven
cogen,, at least from what i think at this time.

bob g

Timsr2 wrote,What about Honda EU1000's, or even EU2000's?.

Wel just seen on youtube that the engine is a new type ,with timing belt ,no head to remove .
i am not so happy with them ,dont say that there not good but not for me.
The old engines are great gx/v series .but at the track [gokart]were had new honda,s 20 gxv200.
on the box was printed made in korea???.
Cheaper ok but after 2 jears of driving ,its not the same as made in japan .
Little more ware on them .

Greetings Wiebe.

Quote from: TimSR2 on December 28, 2010, 07:35:55 PM
What about Honda EU1000's, or even EU2000's?  They are reasonably priced, standardized, can synchronize with each other, and are common as dirt.

I guess you and I have a different idea of "reasonably priced".  :) While I really like the idea of multiple parallel generators, I don't think air cooled engines are a good choice. It's going to be a lot of work to catch that heat and I would have concerns about how efficient that is. One EU1000 cost more than a 4 cylinder engine would.

The other issue is that water cooled engines simply live longer, since they are much more thermally stable. What I'm thinking is that I'd want to entirely insulate my engine so that it never cools off, at least not for a few days, so it doesn't have to warm up again. The other thing about the EU generators is they run at pretty high RPMs for full output, more than 3600 I think. They are long lasting compared to, say, "Chonda" generators, I don't know if they're quite up this task though.

Then again, if you could get the air/air heat exchanger worked out, maybe you could simply get a $299 Harbor Freight generator with a 2 year unlimited hour warranty, and plan on buying a new one every two years...

Quote from: mobile_bob on December 28, 2010, 10:31:36 PM
we certainly have kicked several idea's all over the parking lot with this discussion, however my original thought was more inline with
trying to agree to a common platform  that several folks could work with to develop the ancillary parts that are needed to make a cogen unit.

i guess the problem will always come down to choice of fuel, sizing issues, and personal preferences to some degree or other.

Certainly we could share a lot of ancillary parts between different engines - specifically stuff like carburetors and governors. Even though we're all interested in different engines, we're usually all looking for roughly the same amount of HP...

This could be an option to look at for air conditioning...
http://www.econoheat.com/waste-oil-equipment/air-conditioners/
I wonder how hard it would be to simply replace the oil burner with an exhaust pipe? I bet they aren't cheap...though the oil burner part is probably the most expensive.

How about this - what if you used a manual transmission with overdrive to drive your generator? (engine/trans come in pairs cheap) This way the engine would only run ~1400 RPM - BUT - you could also easily use the stock cruise control setup for a governor! No?

How (in)efficient would a small manual trans be in overdrive vs a belt drive? And, would a normal cruise control setup have tight enough tolerances to keep a generator at the right speed? "Old car parts" are cheap and plentiful. "Generator parts" are custom and expensive.

(seriously, it's 4AM, this cogen idea IS keeping me up at night!)

One last thought before I go to bed.  ::)

The GM Ecotec 2.2L engine.
Available "off the shelf" here:
http://www.jegs.com/i/GM-Performance/809/19156263/10002/-1?parentProductId=956489

QuoteA reputation for performance, durability and adaptability has made the Ecotec the "small-block" of four-cylinder engines.

(since it's a GM performance parts crate engine I assume all parts are available through any GM dealer)
They are probably available from your local junkyard significantly cheaper, I haven't checked yet.

Better yet, this engine comes stock at 10:1 compression and more stroke than bore!
http://en.wikipedia.org/wiki/GM_Family_II_engine#Displacement:_2.2_litre

QuoteUnlike its notably harsh predecessor, the L61 was designed for smoothness. Dual in-block balance shafts were integral to the design, and all accessories were mounted directly to the engine block to reduce vibration.

I like the Idea of a self regulating (kw sizing) system.

Somewhat like Bio mentioned with the transmission to set the rpm... I do not think using a transmission of any type (Mechanical) will suffice, due to losses. Although if it was acceptable to do, I feel one could use an Automatic Trans with the converter "Locked" and by doing so a control could shift the unit as needed to attain the desired load matching. I still think the mechanical inefficiency would still kill the concept.

What if we build a system using an engine sized for the highest expected "Typical" load and direct couple it to a generatoring device (The optimal type for the job) that can output useable power from IDLE to MAX RPM. Then Via Electronics (Inverters, Rectifiers, Regulators, Controllers...) we throttle (size) the unit to match the demand. By using this approach we could also have engine driven AC when desired.

The engine could be Multifueled if so desired in your favorite flavor's to suit the situation at hand. e.g.  Woodgas, Gasoline. or Diesel, Waste whatever, Woodgas, Nat or Pro Fumigated/Ratioing.

O.K. I will quit rambling on now... Sorry
Rob

There is a product out their that i saw for sail boats that had a variable speed belt drive system hooked up that kept the generator at 60 hertz.
I tried to find it, but can't seem to locate it.
There are many variable speed belt drive systems that adjust by cranking a handle.
What would be cool was if a system could be developed that would adjust the belts to suite the load. Small load and the engine just idles along.
Increase the load and the engine speeeds up, the belts adjust to keeps 60 hertz on the gen.
Sort of like and mechanical inverter generator.

Chris

Just a thought on engine options for natural/propane gas.
How about forklift engines. There must be a bunch of those around. Propane and probably about the right size.
I see many of them running aroud wharehouses etc.

chris

I think the belt would be less efficient than a transmission. I do think you could use a fork truck engine. although I dont think that is an advantage unless you can find the right one... if it exists.

I also think that when some of the more knowledgable members read my lofty post, they will likely advise of the cold reality of such an approach... Maybe I'm wrong but it all sounds to good to be true for the average DIYer.

Rob

a very good manual transmission probably will still eat 10% of the available power, an automatic would be out of the question
at the low power levels we are seeking due to the hp needed to drive the internal pump, heating and converter losses.

a well engineered belt drive is on the order of 2% in losses.

another issue with using a transmission and shifting gears will be a problem in maintaining stable rpm
i suppose one could put the belt driven governor on the genhead instead of the engine, but not sure in the end
if the gain in utility would not be largely or wholey offset by the losses.

bob g

FORD VALENCIA (VSG) engines are currently available in only one model, a 1.3L engine rated at 32.8hp at 2800 rpm. (A limited supply of service replacements for the earlier 1.1L size with a continuous rating of 27.5hp continuous at 2800rpm are still available).  These four cylinder engines are very smooth and exceptionally quiet when compared to most air cooled engines. Either model can be CARB (California Air Resources Board) certified when in equipment requiring less than 25 horsepower and can operate on gasoline, LPG or natural gas.
http://www.powertechengines.com/20_30.html
Additional information is given on the Ford Power Products web site at  Ford North American Engine Chart, which also has a link to a .pdf file version of the VSG-413 engine data sheet.

VSG compact engines include cast iron cylinder block and head for durability, replaceable exhaust valve seat inserts for operation on dry fuel, and five main bearing crankshaft for smooth performance. We are aware of VSG engines reporting in excess of 14,000 operating hours before repair in co-generation applications.

Valencia engines are distributorless (DIS)! No more replacing ignition points, condensers, distributor caps or rotor . . . there isn't any! Scheduled ignition system maintenance includes only spark plugs and spark plug wires.

Compact, these engines weigh less than 240 pounds, are 29"H, 25"L and less than 20" wide with radiator. Aerial lifts, sweepers, generators, carpet cleaners, and airline ground support are just a few current applications for these engines.

Interesting web site. Here's a story about 50 year old Ford pump still running on gas:
http://www.powertechengines.com/Ford254WaterPump.html

Really doesn't surprise me that much with a big old hunk of American iron...then again I drive a 37 year old truck every day. (all original)

I'm really thinking hard about a CNG conversion for the truck now...we're talking a dollar a "gallon" for natural gas or $3.29 for premium unleaded with 10% ethanol and even more for diesel. I see some home CNG compressor units on ebay...tanks are sure spendy though.

How about a spark ignition Kubota, it's the same engine as the super-mini diesel factory converted to gas/lpg.

Lloyd

http://www.ai-engines.com/pdf/kubota_engines/spark/wg_df752.pdf

Dammit Loyd!

Now I want one of those little Kubota's. My wife is gonna kick my ass if I drag one home! ;D

Rob

Quote from: Lloyd on December 30, 2010, 09:32:50 AM
How about a spark ignition Kubota, it's the same engine as the super-mini diesel factory converted to gas/lpg.

Lloyd

http://www.ai-engines.com/pdf/kubota_engines/spark/wg_df752.pdf

I like...how come the cool stuff never has a price tag?  ;)

I still would like to know more about the total combined efficiency of natural gas and diesel. If you convert a diesel engine to spark ignition like that kubota, will it run better on diesel/NG mix or straight natural gas with a spark?

Quote from: Lloyd on December 29, 2010, 11:12:00 PM
FORD VALENCIA (VSG) engines are currently available in only one model, a 1.3L engine rated at 32.8hp at 2800 rpm. (A limited supply of service replacements for the earlier 1.1L size with a continuous rating of 27.5hp continuous at 2800rpm are still available).  These four cylinder engines are very smooth and exceptionally quiet when compared to most air cooled engines. Either model can be CARB (California Air Resources Board) certified when in equipment requiring less than 25 horsepower and can operate on gasoline, LPG or natural gas.
http://www.powertechengines.com/20_30.html\

wonderful thread here guys.  a very interesting read.  and where did tim come from?  he seems to know everything about engines.  thank you for all the knowleged explored here. 

here below is what i've learning investigating the same.  i too think the fuel hacker future is increasingly in spark vs diesel. 


-----------------------------------------

inline 4s and 3s

sadly, the ford vsg engine is gone.  i wanted to use it for our rig but couldn't make it a regular sourcer.  its still a great engine for a one off, and already set to go with gaseous fuels usually.

the nissan A14 and A15 are similar go to solutions, but they too are no longer available new in the US new.  i tried that too.  lots there used, and they are well proven and loved.  for one offs, a great choice.

the kubota 3cyl 962cc is my current favorite.  they are 3k new, but nearly no used.  the oil field guys report 15k hours and still going on the first prototypes that were put in somewhere in montana.  kubota is making noises about coming out with a bigger one.  so far unseen.

the current gm small industrial spark engines are here:
http://www.gm.com/vehicles/innovation/powertrain-technology/engines/specialized/industrial/industrial_engines.jsp

people seem to frown on the 1.6 and 2.4 4cyl vortecs as having too much plastic and not terribly robust.  (no personal experience.  anyone here have one).
the 3.0l 4cyl is another story.  it is a full cast iron motor with a long history.  i think (maybe) a descendent of the iron duke, but not sure.  the 3.0l gets lots of marine use too.  the gm suppliers in the oil fields steered me away from anything below this.  the v-6 and v-8 vortecs in the industrial lines are highly regarded from reports so are

the current line of ford engines seem the choice in the 4cyl sizes.  i tend to see current gen builders using the fords in 4cyl, then chevy in v-6 and v-8.  can anyone assess this summary?  my confidence in it is middling.

ford has a 1.6 and a 2.3 inline 4 currently.  i do not know the gen or pedigree of these engines.
http://www.edi-dist.com/ford_TSG_416.asp
http://www.edi-dist.com/ford_DSG_423.asp

is this the ford engine you all were reviewing positively a few pages back?  not sure if that was a previous generation or not.

the toyota r22 seems a wonderful choice with lots of parts.  it seems one wants to stay with the double timing chain versions to minimize their known propensity to break and take out the rest of the show. 

the wisconsin v-4 engines seem about gone.  not much work on them these days to keep up with emissions issues.  a side valve engine gets difficult.
http://www.mgbryan.com/products/engines/wisconsin

diahatsu has a 950cc 3 cyl that gets used in small ute trucks all over the world, but not too much in the us.
http://www.daihatsu.com/catalogue/engine/showroom/

-------------------------------------------------------------

v-twin options.

in the v-twin world, there are growing water cooled options.  i went through the large air cooled options and found them a bit loud, and the lack of water to do things is less than ideal.  i decided that water was not negotiable.  otherwise, kohler goes up to 980cc and it is a great engine. 

kohler has a 750cc water cooled job for about $1900
http://www.kohlerengines.com/onlinecatalog/productDetail.htm?productNumber=Aegis%20LH755

kawasaki also has 750cc and 850cc water cooled units.

750cc water cooled
http://www.kawpowr.com/engines/detail.aspx?id=6&cat_id=1

850cc water cooled, efi
http://www.kawpowr.com/engines/detail.aspx?id=54&cat_id=1

at least on the kohlers, the mech governors don't like to perform well below about 2200rpm.  they get particularly fussy below 1800rpm.  the weights are calibrated for elsewhere. 

subaru-robin doesn't have any water cooled

yanmar is diesel only

perkins no spark at small scale


but course there is the harley.  many generations and many parts there to make your slow speed shake the house down thumper . . .

j

On the subject of adding a distributor to an engine that didn't have one before, such as converting an existing diesel to spark ignition. This I have seen done.

A very handy old friend of mine had a machine shop powered by a 8 hp Fairbanks Morse gasoline engine, but the original ignition system failed and was hard to find parts for, and was noisy even when it worked.  Rather than change the engine out to something more modern, he added a 70's datsun distributor to it, on an external toothed belt drive. IIRC the gears and belt were from a vacuum cleaner power head.  He just fitted  a little gear, added a zerk fitting to it for lubrication, ground off the points cam,  used one wire on it. Engine ran fine for years that way in daily use.

It looked pretty wild, but it worked great.  At the speeds these engines turn even a bicycle chain would work.

The point I wish to make here  is that it is probably easier to knock down the compression ratio by adding gaskets or base shims to spark convert a diesel than some of the other things we have discussed in here. For many of us that would mean being able to keep their investments  and just change direction a bit.  So putting a lister CS or a changfa on NG or propane is a reasonably straightforward proposition. And they have the mechanical governors we need for electrical production built right in.

One need know the CC displacement of the combustion chamber, (easy to measure for yourself)  thickness of gaskets  and the bore and stroke, and what compression ratio you want achieve. It doesn't take much shimming to knock a few points off the CR. Calculators are online on most racers websites. 10 to 1 is  a good conservative number for propane,  or 12 to 1 for NG.

Then just get rid of or disconnect the pump(s), Connect the governor to the carburetor throttle lever somehow, stick a sparkplug in the injector hole somehow, pick one that doesn't hit the piston crown.  Bodge on a modified old 4 cylinder distributor with a toothed belt or a chain drive, install your lockoff and mixer....  Adjust spark timing to about 25 degrees total advance..... crank her up and set your fuel mixture as lean as possible.

Then some fine tuning for governor response, and ideal spark timing and fuel mix and you have a lovely low speed  understressed super quiet dry gas engine.  At reduced power of course :-(

Quote from: TimSR2 on December 31, 2010, 11:15:19 AM

 So putting a lister CS or a changfa on NG or propane is a reasonably straightforward proposition. And they have the mechanical governors we need for electrical production built right in.

Then just get rid of or disconnect the pump(s), Connect the governor to the carburetor throttle lever somehow, stick a sparkplug in the injector hole somehow, pick one that doesn't hit the piston crown.  

interesting coincidence in the universe that otherwise tends to not cooperate:

1. the injector hole size in a standard lister cs head is a perfect fit for a standard automotive long reach spark plug.  you can even repurpose the injector bolt down assembly with a hollow tube to hold down the spark plug.  for those who didn't see the earlier threads, here's our doc on doing so.  http://www.gekgasifier.com/forums/showthread.php?t=312.   (we later did it through the compression adjust plug, so as to retain both the diesel and spark ability at the same time.  you can see that here: http://wiki.gekgasifier.com/w/page/30448258/Spark-conversion-for-Lister-slow-speed-diesel-engines)

2. the injector hole in our local changfa r175 is about perfect to insert a 10mm motorcycle/chainsaw plug.  there are now 10mm and i think 8mm very small spark plugs that make installations in these smaller holes possible.  some engines you can likely even get them in the glow plug holes.  

so in both the lister and changfa case, you can convert to spark without machining or compromising the original motor.  and as tim said, adding gaskets is easier than milling heads and considering new piston clearance issues, on the road to reasonable compression.  

there are many ways to spark the result.  one electronic option using an arduino is explained here: http://wiki.gekgasifier.com/w/page/30448258/Spark-conversion-for-Lister-slow-speed-diesel-engines.  this is ken boak's work.


jim

while i find the spark conversion of a diesel interesting, the engine will have to have its compression reduced
this is not the case for a dual fuel diesel, where there are examples of the chinese engine's with greater than 17:1 compression
doing just fine on natural gas, and there is evidence that propane can also be used but with a lower percentage of offset

a couple of advantages

1. the engine does not need to be modified

2. no spark plug and ignition system

3. no alteration to the governor or fuel system, allowing for seamless changeover to diesel and back again

4. lower emissions, lower NOx, lower particulate, lower co2

5. perhaps most importantly little to no loss in efficiency or output power

disadvantages include

1. having to have two fuel sources in order to run in dual fuel mode

2. possible detonation, rough running, vibration, damage if the gaseous fuel is not meter correctly to suit the load on the engine.

quite frankly i don't know why the gasifier boys haven't worked more with the small diesel in dual fuel mode, aside from the need for a pilot fuel
(diesel) the pros more than offset the cons in my opinion.

having said all that, i too plan on doing some experimentation at reduced comp ratio and spark ignition, however it would appear that the diesel left as is
and fueled in dual fuel mode would outperform and be far simpler to deploy.

at least that is the way i see it... maybe i need to clean my glasses?  :)

bob g

2. possible detonation, rough running, vibration, damage if the gaseous fuel is not meter correctly to suit the load on the engine.


Doesn't happen. Methane and Propane have  a much wider useable range of efficient air/fuel mixtures than gasoline, and so much higher octane rating that pinging is rarely a concern...   if the mix is too lean the power is low, if too rich the exhaust smells fuelly. They are easy to tune by sound and smell.

If the CR,  load, and ignition advance are kept within reasonable limits, a drygas engine can be run at WOT virtually forever. The valve seats will probably clap out a couple times in the life of the engine, if not made of Stellite. No big deal, Stellite seats aren't very expensive at  a good automotive machine shop.

Tim

it most certainly is a concern in a diesel engine that fueled with natgas or propane in dual fuel mode
if you exceed the upper offset limit (which changes with loading and engine design, along with compression ratio) you end up
with vibration, detonation, pressure spikes and engine damage.

this is a totally different animal than a gaseous fueled spark ignition engine where the comp ratios are from 10 to 12:1

a diesel engine running in dual fuel mode often is higher than 15:1 and sometimes as high as 20:1

read the test results from the pdf link i provided for the bangladesh testing

at full load the amount of natural gas has to be reduced from about 88% (at 75% load) down to 67% at full load
otherwise the engine becomes very erratic in operation, with heavy vibration/detonation and other less than desirable things happening, that
left unchecked usually end up causing engine damage.

natural gas, and definitely propane does not have anywhere near high enough octane rating to operate  at very high compression ratios in a spark ignition
engine, and in order to operate successfully in a diesel in dual fuel mode certain metering must be adhered to on the the rich side,

on the lean side you can get away with whatever you like, the only thing you lose is fuel cost savings by running overly lean rather than up to near as practical to the offset matching the load.

excellent matching of the amount of nat gas to the load will require some sort of computer control to optimize to the Nth degree, however this is a very narrow window to operate in, the window widens if we back off the amount of natgas and run at less than optimum offset levels.

i think that is a fair trade off or compromise, at least in testing
after deployment it might be that a computer control to adjust the offset on the fly, might well pay for itself in fuel savings very quickly.

bob g

Quote from: mobile_bob on December 31, 2010, 10:41:21 PM

quite frankly i don't know why the gasifier boys haven't worked more with the small diesel in dual fuel mode, aside from the need for a pilot fuel
(diesel) the pros more than offset the cons in my opinion.

here's at least what happened with me.  

in principle, i agree is sounds great.  in practice, i found the dual fuel control on these small engines to be extremely touchy.  it takes such a small amount of liquid to get to no load full rpm, that a minor error in your set liquid amount can lead to an overspeed.   larger engines with larger rpm seem to have more running resistance you need to overcome to get to speed, thus less sensitivity in the liquid set amount.

also, it only really works for the lister, as you can get to the governor linkage and detach it from the injection pump so you can use the gov for your gaseous valve, and pin the injector pump where you want it to hold steady.  on the changfa, it is all internal and you can't easily repurpose the mech gov to control your gaseous fuel, nor easily hold the injection pump in a single place.   doing it the other way (pinning the gaseous portion and varying the diesel) gets into even more problems.

before actual experience, i too thought dual fuel would be the way to go.  that's why i started with the lister and china diesels to make integrated gasifier gensets.  you can see the early lister and china diesel ones here:  http://www.gekgasifier.com/wpgallery/gek-gasifier-genset-older-versions/ (http://www.gekgasifier.com/wpgallery/gek-gasifier-genset-older-versions/)  it didn't really work that well.  the result was not something a non-expert should ever touch.  also, i just got tired of fighting the variable quality, old engineering and weight issues of the lister-changfa options.  i wasn't finding a total value.  it was not "cheap" in the end.  so then i started on the v-twin route spark, which you can also see above.  then the kubota.  

if one has a good and constant load, all should be fine.  but as soon as you have detached the injection pump and pinned it in some place, you no longer have the certain safety in overspeed that the governor usually provides.   if doing dual fuel with the liquid set for pilot, i would encourage only doing this with a solenoid shutoff that is run in parallel with spark.  don't pin the liquid rack physically to the run point.  put it on a solenoid to the run point, thus when you shut off the ignition, the rack still goes to absolutely shut.  the pilot dual fuel can be sneaky and easily get out of control.  

remember, diesels can run away on crank case bypass oil.  this is why some have intake dampners.  true, not usually needed.  in a dual fuel pilot injection scenario, if a hack injection rack set screw can easily come loose and bad things will follow quickly.

then adding the new butterfly to the above, i was quickly getting into as many or more control issues in dual fuel than with a spark engine.


more reasons.

wood gas tar converions falls apart at low pull rates, as temps fall.  minimizing wood gas use has not been the problem.  at this point i can run down to about 1kwe without external gas dumps and still keep things hot enough, but that was far from the case in the beginning.  dual fueling only made the low end fuel consumption lower, which was the wrong direction to be going.

also, after one has suffered through the pain of getting a wood gas system to work, it is a let down to use any liquid fuel at all.  it is much more pleasurable to run 100% wood gas.  that is the magic.  junk in - -  power out.  it is better undiluted.

all this led to an assessment that there was no "simplicity" and little pleasure to be found in the dual fuel small engine scenario at least for wood gas.

this calculus may change if working with nat gas.  and mileage always varies given your specific context.  i just clearly wasn't working out in mine.

jim

Quote from: TimSR2 on December 31, 2010, 11:15:19 AM
On the subject of adding a distributor to an engine that didn't have one before, such as converting an existing diesel to spark ignition. This I have seen done.

I think you would be much better off with a distributorless system. I've always hated distributors. There are a handfull of aftermarket spark systems mostly based on Ford EDIS parts. The Arrow 4 and 6 cylinder engines have a distributorless CDI setup. Probably some efficiency to be gained if you're not driving a distributor...

Quote from: mobile_bob on December 31, 2010, 10:41:21 PM
while i find the spark conversion of a diesel interesting, the engine will have to have its compression reduced
this is not the case for a dual fuel diesel, where there are examples of the chinese engine's with greater than 17:1 compression
doing just fine on natural gas

And with that I have to wonder...is that a good thing? Is it a simple "rule" that more compression = better efficiency? Or is there a certain point of diminishing returns? Something I have noticed about all these dedicated natural gas type engines we've been looking at, like the Arrow units, is that they are not converted diesels, and they usually only have 9 or 10:1 compression, even though the rest of the engine is optimized for fuel efficiency and natural gas. Why do the commercial spark ignition NG engines not use a much higher CR? Obviously it's not about saving money, when the engine cost probably 15 grand or more...

With my system I would really, really, really love to be able to produce electricity at the same rate as the power company - though according to my calculations I'm still going to be at 16-17 cents/KWH vs ten cents from the PoCo. I need a more efficient engine or cheaper gas. They won't notice if I dig a hole next to my gas meter will they?  ;D

Here is some intresting stuff.

http://www.dualfuelstrategies.com/

http://www.energyconversions.com/ECO.htm

http://www.energyconversions.com/Ecohardware.htm

http://www.cleanairpower.com/components.php

http://www.cleanairpower.com/duel-work.php


Henry

thanks for the links Henry, the second of which provides support to what i stated in the thread relating to making a case for natural gas.
and follows very closely the results found in the pdf report from bangladesh as both relate to "knock" limit and the non linear natural gas
offset vs pilot diesel injection once you get over about 90% power level (in the bangladesh paper) and over about 75% in this second report
that shows up in the graphs on the catapillar engine's.

their use of computer control and fuel mapping for the offset of natural gas vs pilot injection is the epitome of dual fuel operation, however
it is doubtful the DIY community will ever adopt such strategies unless the technology is available for a very low price (which is also very doubtful)

the link you provided clearly illustrates some of the issues, showing clearly that dual fuel with nat gas is not just simply fogging the gas into the intake
in some crude manner without concern to outcomes, thinking that the engine will respond like a spark ignited engine that has much lower compression.

clearly two different animals all together, each having their respective pros/cons and set of compromises that must be made.

bob g

"not just simply fogging the gas into the intake"
Too true, I convert vehicles to LPG and have done several diesels - post '01 diesels (in Aus') require a computer controlled management system and they are recommended for hard working vehicles, the exhaust temp' probe that shuts off the LPG over 600C is worth it's weight in gold, but we're not talking about road trains and those systems are pricey.

For pre '01 vehicles and gensets I'm happy to fog the gas in through a small orifice, about 3 to 5mm and have it powered via a throttle switch or turbo boost switch so that vapour only flows when the engine is starting to work, not at idle.
The orifice sounds tiny but it is easily checked by running the engine up to 2800-3,000 rpm and then switching the gas on, you are looking for the rev's to rise by 200-250 rpm

At this flow rate you will use one litre of LPG to every three of diesel and no modifications will be required, it will act as an accellerant and burn up the normally wasted diesel - no more black smoke, more power and, after two or three oil changes, no more black sump oil

Cheers
Rob
http://nakedmechanic.blogspot.com/

In the spirit of finding something cheap, and available, take a look in your local craigslist for old CNG vehicles. Alot of CNG fleet cars are around from ~10 years ago. This way the engine will already be setup for natural gas use, and you might get some extra stuff like tanks, plumbing, intakes, and ECMs all specialized for NG.

This would be a perfect example:
http://portland.craigslist.org/mlt/cto/2146254395.html
I think I might find out more about that engine...