Redstone Diesel: woodgas optimized engine?

[Steve Unruh]

Yes I did mean George Brekenridge(sp) and his Utterpower group in in Washington state. They seem to bringing these generator heads in from China in 400 lot groups. You can read his info Daniel listed on these unit and get a flavor for George. I do agree with every thing he says as far as gen head failure patterns.
My own 7.5 Kw gen head is a brushless Italian make Mecc Alte. It is as simple as I could find yet still has a lot of copper windings, 9 diodes and 3 thyristors.
As Jim Mason defined the 7-25hp mechanical engine output of this tread using the standard 2hp per kilowatt electrical generated rule of thumb it would take two or more of these non-size upscalable Utterpower/PMGs to effectively load/utilize the higher HP engines. I keep thinking Diesels as a heat ignited engine which MUST be loaded to produce the combustion heat to run clean. Gasoline/petrol engine can be unloaded and idle ran with fewer problems. WoodGas fueled I just don't know yet.

Old Chuck please do realize Jim has started a very specialized discussion here to explore what is the optimal engine configuration for the unique combustion properties of woodgas fuel, and can we acheive this in readiliy available/modifiable engines.
Some of the major engine companies know how to do this in large expensive industrial sized engines. The few engine companies doing this in small engines such as Arrow are designing for an expensive commercial user too.

Most are using what they have.
A standard unmodified gasoline/petrol engine suffers a minimum 30% to 50% power loss due to the lower BTU content and slower flame front burning. What could we gain back if we used the higher knock resistance of wood gas to use higher than possible with gasoline compression ratios? Is a long stroke/small bore (but high piston speed) going to be better than a bigger bore/short stroke (but slower piston speed).
Diesels used unmodified show only a 15% to almost no power drop if turbocharged. But they require a separate expensive fueling system and fuel. And if/when your gasifer fuel bridges, burn channel cavities, or just burns low of fuel unattended and then belches out smoky/tarry fuelgas and tars up a diesel engine they Are going to be much more expensive to tear down and repair.
So unmodified gasoline you must upsize (heavier, larger, poor fuel economy - just how much wood do you want to source and proceees?) to get your needed power output.
Unmodified diesel; pay more upfront and when/if you force yourself into teardowns, pay much more later to get it running again.

More later if anyone is interested.

Regards
SteveU.

[oldchuck]

Originally Posted by Steve Unruh

Old Chuck please do realize Jim has started a very specialized discussion here to explore what is the optimal engine configuration for the unique combustion properties of woodgas fuel, and can we acheive this in readiliy available/modifiable engines.

Regards
SteveU.

Yes, Steve, I do understand this. That's why I'm interesting in your comments. Learning from the experience of others. I may very well go out and buy a couple of gensets to see what works best but I'd like to narrow it down as much as possible. What you say suggests there are some serious downsides to take into consideration.

[Steve Unruh]

O.K. oldchuck it's been kinda' quiet here for a couple of days. I'll express some of my opinions learned concerning small stationary gensets.
Please: I DO want others to chime in with their own experiences!!
The actual generator heads (with expensive exceptions) come as 2 pole 3000-3600 RPM or 4 pole 1500-1800 RPM configurations. This is to achieve either 50 or 60 cycles per minute AC electricity. The higher speed 2 pole units are much less expensive to manufacture (less iron,steel and copper) and ship (less weight). The higher speed 3000-3600 units are notorious for centrifugally spinning out their copper windings and self destructing at the least provocation. Either can be directly driven by a high speed 3000-3600 RPM engine or medium speed 1500-1800 RPM engine, OR; BELT DRIVEN.
Oddly enough the cheapest intermittent usage 50-500 hour life throw-a-way 3000-3600 RPM units and the long life military/commercial duty 1500-1800 RPM units most all use direct mounted/drive systems.
I favor belt drive even with the 3-5% power loss and additional maintenance requirements.
1.) Allows you with pulley changes to optimize your engine running RPM do to fuels, climate, altitude, ect.
2.) Allows you to quickly use substitute generator heads. You are not locked into a proprietary hard to get/find only this will bolts up piece.
3.) Properly sized the belt will act as a safety slip joint when/if something BAD happens at either side of the system.
I choose only get involved with a slower (less than 3000-3600 RPM) engine or 1500-1800 RPM generator head.
1.) NOISE. To me. And to others. I personally work around 3600 RPM 4-cycle motors on my sawmill, woodsplitter and mowers. After a couple of hours your nerves are jangling, you are fatigued and you just want to kill something. I've oversized these and running throttled them back to 1800-2200 RPM the jingle/jangle is much more tolerable. Believe me; neighbors who hear less will complain less too..
2.) WEAR. The slower speeds do create much less wear and tear on the parts, will break less and will require less maintenance.
3.) WoodGas has very slow speed combustion characteristics. Even though it can make a 3600 RPM engine go roundy-round, ALL of the historic and current in useage applications say 2000-2500 RPM is the optimal upper RPM range.
I favor a Brushless generator head versus a brush type.
This is a personal prejudice. Brushes are inexpensive to make and service and are a low tech proven technology. Anything brushless will be a much higher tech and more expensive to manufacture and repair when needed.
I just remember it seemed the two or times a year when the mains power went out on the dairy the tractor PTO driven generators would more often than not NOT work due to hung up brushes in my wet maritime climate.
A huge factor is where you live.
"What you locally available is three times more valuable than anything you have to buy out and have shipped in."
Only a local will really know.
If I was in the UK or a former colony country I would search out and favor a Lister S-O-M unit. Bruce Jackson a poster on the Yahoo WoodGas forum said in Iraq currently the best units to obtain and relive were discarded 10KW Kubota diesel powered units the US government contractors had shipped in. Dutch John on the same thread made some knowledgeable comments on what was available in the continental EU.
Here in the US/Canada another AE poster named Mobile Bob pointed out that 8-10KW brand Miller, Linclon commercial gas/diesel welders are locally/Craigs list/eBay for sell for $500.-1500. USD. On most rering the piston, grind the valves and get a Free welder to go with your generator. Problems are when the gen head goes out IT will be very expensive to repair. His valid suggestion was for the cost just go buy another used unit.
On another AE forum for a longest life least maintenance ultimate gasious fueled set up for use on a Texas dude ranch this was recommended:
http://www.arrowengine.com/Products?.../C_Gensets.php
Note that this single cylinder unit is mounted on a 600 pound skid to control the vibration.

So it all depends on what you want, what is locally available and what you can afford to pay. Each of us individually have to make these decisions.

Regards
SteveU.

[oldchuck]

Thank you, Steve. As ever your comments are very helpful.

[Steve Unruh]

Good Morning All
Apparently I'm not being bold enough to get an engine discussion going.
So let me keep inching out on this limb with my engine opinions and prejudices.
Forget anything two stroke, gasoline/petrol or diesel. I just finished scraping the soot off of my wood stove glass front doors from using a wee bit too much pitchwood and forgetting to open up ALL THREE of the controllable air intakes. You really will not want to ever run smoky, tarry woodgas through any two stroke engine: crankcase bearings on the small ones and broken blower rotors drive train on the bigger ones will prove to be expensive.
So on four stroke gasoline/petrol and diesels what would happen?
The goo will coat the valve stems and faces and cause them to hang open and not seal with a loss of compression. On an "Interference" engine the stuck out valve will be hit by the rising piston. More on this later.
The piston rings will "carbon up" stuck causing a loss of compression and "suction" resulting in hard/no starting and loss of power. Loss of oil control past the piston rings will cause fouling of the sparkplugs and at diesel level compressions the crankcase oil into the combustion chamber could even fuel a catastrophic run-away (engine runs faster and faster uncontrollably until destruction).
According to Doug Williams and others the fine soot particles are soft and smooth enough NOT to cause metal to metal wear. I believe this. I also remember an oil called ARCO Graphite that had to be recalled off of the market because on some engines the graphite particles were clustering/clumping and and then heat fusing Blocking the oil flow causing failures.
And any uncaptured/unfiltered out Ash IS abrasive and will cause premature wear.
All of this leads me to believe I really want to use an engine that has readily available parts and is real easy and cheap to tear down, re-ring and de-tar.
Yes. I am assuming I will screw up my gasifer operation.
Yes. I am assuming my gasifer will screw me up with fuel bridging, channeling, burn outs, ect.
The engine won't care who or why - it will keep gulping down crap gas as long as it can. It's hungry, fuel starving.
Think it won't happen to you? Try this.
Get/dust off/go buy a simple cotton wick type oil lamp. Learn to arc trim the wick for an even clean burn (or you will smoke the glass). Learn to raise the wick to light. Learn to lower the lit wick before putting the chimney back on (or you will smoke the glass). Learn to now adjust the wick height to keep it burning cleanly (too high you will smoke the glass).
Let it burn for a few hours - when it goes dim or starts to smoke the glass you will have to adjust the wick height due to lower fuel, wick burning away, room temperature/humidity changes.
Learn to now turn the wick down to minimum burn Before you blow it out (or you will smoke the glass). Crank in down to extinguishing will cause enough smoking to smoke up the glass and drop the wick down out of the adjuster mechanism.
Now repeat and do this every day as training for every day you plan to use a gasifier. Never forget a step, ever, or you will "smoke the glass" and have to clean it up. You will understand why most people embrace a light switch and a wall thermostat.

Shows why many of the historic designs have a final easily clogged up to choke off the engine safety filter. But even that could get spendy if you are throwing away a non-cleanable/reuesable $3.00 -15.00 USD for a new filter a couple of three time a week.
Ever see an engine suck a clogged up filter inside out down into the intake??
I have. Cost that Honda car owner a new throttle body assembly to get rid of the idle surging from the bent throttle plate. Expensive filter change!!
Regards
SteveU.

[ToddT]

I agree 100% that filtration is of the utmost importance. The Moh hardness of the particulate may not cause damage but it may inhibit the oil from contacting the metal surfaces. The end result is the same... oil starvation. Bottom line: filter well.

Having run heated vegetable oil as a fuel in my diesel pickup, I've been thinking about applying the same approach to filtering woodgas. Filter in steps and using as many cleanable elements as possible.

The cyclone is the first step... spin out the big chunks. What else can we use as the next step? The BioMax 25 uses fabric bags that look like pillow cases. They can be shaken out quite a few times before replacement or even washing. Again, I like the idea of reducing the micron rating in steps. Big chunks, medium stuff and finally tiny particulates.

What about using a K&N oiled gauze type media as a final filter? That would give us a washable filter element as the final step.

What should be our final micron rating goal? Liquid fuel filters are typically 10 micron or better.

[oldchuck]

Originally Posted by Steve Unruh

Good Morning All
Apparently I'm not being bold enough to get an engine discussion going.
So let me keep inching out on this limb with my engine opinions and prejudices.
Forget anything two stroke, gasoline/petrol or diesel. I just finished scraping the soot off of my wood stove glass front doors from using a wee bit too much pitchwood ....

Regards
SteveU.

Hmmm, maybe biodiesel is a better idea.

[Steve Unruh]

WOW. I expected at least one of the European fellows to nail me down with the German 1940's experiences with woodgas in their 2-cycle industrial diesels.

Oldchuck yours and mine goals are remarkably similar - to start, we just want to turn some of our wood into electricity. We both have our own wood. I don't have coal, oil, natural gas or even any power capable solar, wind or hydro. I do have a family branch that after shutting down their 100 cow dairy 5 years ago set up 20 of their acres to make their own biodiesel. Please let me off thread for a moment to contrast my 20 acre woodlot against their now 20 acre energy field. I currently supply 5 households with firewood for a full years/270 days of heating. I could easily double that to 10 households for heat, OR; supply enough wood to also supply the electrical needs for the original 5 households and do this substainably. My 20 is untillable glacier rock and fill mixed with old volcanic ash. Their 20 is a heavy so-so drained clayish bottomland. Their 20 produces enough canola oil for them to run their personal diesel vehicles, the tractors and hay/stock trucks for half a year. They heat and power with federal hydro/nuclear grid electricity. If they diverted their biodiesel off the 20 to supply all of thier heat and power needs they could support 1 family only - thier own. If they put their tillable 20 into a people food crop they could feed what? 10? 50? 100? families. This same 20 used to produce enough corn and rye grass silage to feed 30-40 of their hungry Holstein dairy cows for most of a year. They have to plow, disc, lime and fertilize, harrow, plant, weed spray and harvest twice a year. And maintain, fuel and oil the equipment to do this. My trees pretty much selfseed and grow by themselves. You and I know about the harvesting. O-well - keep us fit and spry and add at least decade to our life barring any widow-makers.

High energy dense liquid fuels are really nice - that is why they supplanted all other transportation fuels a hundred years ago. Well the "cheap oil" is effectively gone now. I am sure the new ENERGY companies will keep suppling us with some type of burnable liquid fuel . . . for a price.
In the meantime my trees keep on growing.

So back to engines. These follows ARE currently running their own woodgas through modern multicyclinder electronically controlled engines: Dutch John, Mike LeRossa, Wayne Keith, Johnathan Spreadbough, Terry Nichols, some of the Finns and a few others. The first two are members here now. Reading theirs and others real life starting up, running and shutdown procedures says it IS possible with the same amount of attention a gasoline/petrol vehicle operator had to give back in the 1920's thru 1940's. Jim Mason and some of these follows through better engineering and automation controls are determined to bring this down to the level of vehicle operator attention required in the 1960's. Remember: pump the throttle twice to set up the automatic choke and and fast idle cam and to give it a squirt of starting up gasoline; once started - blip the throttle to kick down the now too high speed, let 'er warm up a couple of minutes, blip down the idle again, drive off slowly/carefully for the first few miles until fully warmed up. Oh yeah, take it to your local mechanic (me) twice a year to clean, adjust and make all of these automation controls functioning. We've gotten spoiled with our modern "no touch, drive-a-way" fuel injections.
Sometimes one of these fellows will mention an early learning mistake engine OOPS. They all pretty much say do your learning on a walk-away, throw-a-way engine first.
As a former auto tech/mech. I'll save my multi-cylinder, multi-valve overhead cam work for people willing to pay. Two jobs already on my plate waiting for warmer weather: DOHC 2.4L Chrysler and a SOHC Ford V8.

So my opnion is for this 7-25 HP application best to use a V-twin, opposed 2 cylinder or 3 or 4 cylinder inline engine so long as it has overhead valves.
I cut teeth on valve in block (flat, I, F head) engines. They were cheaper to manufacture but with the large offset combustion chamber you will never get above a 9/1 compression ratio. Also the gasses in and out path is a restrictive torturous "S" then "U" shape. Valve in head designs with the heads removed sitting on a bench are Much easier to work on. Can have compressions up to 23/1 and can have fairly reasonable flow paths.
Overhead cams are unnessary, we don't need their RPM speed potential. OHC won't hurt but YOU get to work with the long stretchy chains, worn guides and gears; or belts, tensioners, pulleys and covers all just to get the cylinder head(s) off. For this application I'll stick with nice simple cam in block and pushrods design.
Still need to cover "Interference/non-interference" and diesel DI versus IDI.
Anybody?

ToddT I do use K&Ns on all of my road vehicles. They are suppose to work better with intake pressure pulsations like small engines have. I am going to try if i can get the woodgas cool and dry enough. I burn wood for heat and am/was an automotive emissions tech. We were trained and shown that every gallon of liquid fuel with complete combustion would produce Over one gallon of condensible water vapor. I would not have believed how much condensible water comes out of a GEK gas flow untill I saw it. Excessive fuel moister, air in relative humidity and combustion H2O DO add up. Only some gets H2, C0 disassociated. Wait till you see this yourself. Read Dutch Johns posts here and on his web site and hear his gas drying concerns for his dry filtration. Once you see this moister output you can divide the guys I listed above who do know this into the wet cyclone/washing group from the ones who know this this would freeze up solid on them in the winter.

Regards
SteveU.

[oldchuck]

Steve-

Interesting post. We do have some things in common and some interesting differences. I think I'll start another thread to talk about all that, maybe in fuels or maybe general discussion would be better. This thread has wandered some. The tech talk suffers from Jim's silence. Hope he is busy solving my problems.

I do read the wood gas Yahoo group although it is often a PITA, poor format, many irrelevant posts, and a lot of stuff that just goes over my head. I am mightily impressed with Dutch John's engineering, also with that guy in Florida, Bruce Chovnick. Problem is I ain't an engineer or a mechanic.

I'm wondering if Chovnick's good results are due to extensive water filtering. And you mention a water filter freezing in winter. A guy in Florida wouldn't have that problem. Anti-Freeze? Moisture- very dry fuel- clean, dry gas, connect the dots.

[jimmason]

Originally Posted by oldchuck

The tech talk suffers from Jim's silence. Hope he is busy solving my problems.

folks, sorry i've been so quiet. we have multiple new new things about to come out of the shop and they have been consuming my time. most importantly we're finalizing the v3.0 gek, which has various new interesting things. i'll post elsewhere with the list of changes to get everyone's input. but generally, the long running list of "what should be improved/changed/altered/etc" we've all been contributing to for months has been integrated into the new version. we keep an internal running list of desired changes and these all get integrated at every new major version change.

the integer version changes are major things which require new cut file sets and major component reorgs. the .x version changes are adjustments within existing sheetmetal parameters. the v3.0 changes sheetmetal things so it is a major process to verify a full new file set and associated production issues.

bear also has some interesting updates on the internal tar recycling nozzles that he will post tonight or tomorrow.

you all are most welcome and encouraged to carry on without me when i need to disappear into offline fronts of gek work. i am only one. you are many.

jim

[Terry J Reich]

Originally Posted by jimmason

the integer version changes are major things which require new cut file sets and major component reorgs. the .x version changes are adjustments within existing sheetmetal parameters. the v3.0 changes sheetmetal things so it is a major process to verify a full new file set and associated production issues

jim

Hi Jim,

Hopefully there will be a kit to upgrade GEK V2 to V3?

Cheers,

Terry

[RobWindt]

The last update on the Fluidyne site mentions the Prakash 15 kWe gas engine generator made in India - it looks like a diesel with spark ignition but details are hard to find
http://www.fluidynenz.250x.com/index.html

[Steve Unruh]

Good find Rob Windt!!
Looks like a three cylinder engine pictured on the Fluidyne Tasman Mk3 Update.
Looking at the "Renewable Energy" section on the Prakash site:
http://www.prakash-india.com/product/biomass-genset.htm
this looks like a derated #PNG-20-M genset with a #PN-3-BM three cylinder engine.
In the same section under Biomass they show a gasifier assemble:
http://www.prakash-india.com/product/about-bio-mass.htm
Under Biogas they list the a compression as 13.5:1
And yes, to me the block and cylinder head casting DO look just like their diesel engines.
Odd they list a different displacement and bore sizes for the Biogas versus the Biomas 3 cylinder engines engines.
As an old engine man what do you think of the 3 cylinder engines versus an inline 2 or 4 cylinder configuration?
Regards
SteveU.

[RobWindt]

my knowledge of diesels is sadly lacking but the wish list that you and Jim have proffered here makes sense, my background is mainly auto' LPG conversions and keeping stuff running well past it's use by date

The Indian unit looks well suited to the job but like most of their machinery, I would be inclined to strip and inspect it before firing

Rob

[jimmason]

i agree. good find. i need to write these folks and explore the particuars. while we can convert china diesels on our own, a purpose made done unit is very attractive. this is also aimed at a more industrial market than most listeroids, thus i would guess the quality control is better.

[Terry J Reich]

Originally Posted by jimmason

i agree. good find. i need to write these folks and explore the particuars. while we can convert china diesels on our own, a purpose made done unit is very attractive. this is also aimed at a more industrial market than most listeroids, thus i would guess the quality control is better.

Here's the prices (FOB Delhi, $US, 1 yr warranty, 4-5 weeks delivery):

Engine alone (Power at 1500 RPM (BHP):

20 HP: $4395
38 HP: $6920
56 HP: $8450

Engine & Genset:

20 HP & 12 KW: $5220
38 HP & 24 KW: $8590
56 HP & 32 KW: $10570

Of course these are prices for one....Jim would be ordering 100 units at a time! LOL

[kerrynzl]

Why are you guys looking at spending lots of money on foreign rubbish and considering spending even more converting diesels to spark ignition??

Use a Small block 350 Chevy and raise the compression to about 14 to 15:1
Both petrol or a diesel engines have the same piston to valve clearance problems [ worse for a diesel ] , It's all about valve timing and piston notching.
Buy a 350 crate engine and install "327" Chevy Flat-top pistons [ these have a 0.135" taller 'compression height' for the shorter stroke 327 ]
On a standard Chevy at TDC the pistons are approx 0.040" down the bore so the 327 pistons will be 0.095" above deck height.
Use a set of small port 305 Chevy cylinder heads with 58cc chambers

Then get a competent machinist to "flycut" the cylinder heads for the protruding pistons and also notch the pistons for valve clearance.
Get a good short duration industrial cam grind for low RPM torque

A new engine is $1599.00 part # 10067353 [ buy a $50-00 junker for all the manifolds etc ]
all the other mods could be done for less than $1000.00 [ DIY except machining ]

http://www.currymotors.gmmotors.com/...350Engine.aspx


In a pickup these things can do 500,000 miles
[ at 1800 RPM it'll still be going at my funeral ]

[Dharris894]

I am no mechanic but I know there are a lot of big bore high compression motorcycle engines out there.

Also (again just a newbie) how come natural gas/propane engines wouldn't be the best place to start?

[kerrynzl]

It's all about being economical [ otherwise we would not consider wood fuel at all ]
natural gas / propane generators cost too much for the average DIY person

most motorcycle engines have long duration cams which lower cylinder pressure [ but also have high compression ratios to compensate for cylinder pressure loss ] this makes for a peaky high rpm engine.
For a gas generator engine it is desirable to be operating at low rpm constant revs so it'll need a short duration cam [ valve timing ] and high static compression [ for gas ]

In the late 70's early 80's the New Zealand govt was promoting CNG as an automotive fuel [ the Govt even gave out subsidized fuel vouchers ]
The Chevy I mentioned previously was very similar to one I had built in the 80's except it had a 400 crank and rods fitted into a 350 block making 383 cubes with 327 pistons and old 283 heads were flycut.
It slugged around like an old diesel but only cost about $5.00 a week on subsidized CNG

[ToddT]

Thanks for your real-world input. I've been thinking along these lines for quite some time.

What about filtration? Have you considered a diesel particulate filter for cleaning up the woodgas prior to the engine? I like the idea of a staged filtration: cyclone, larger micron bags, etc. Don't try to do all the cleaning in one step but rather drop down the particulate size in steps.

How would one of these engines run as a dual fuel unit? I like the idea of having a backup fuel option. And, with that in mind, what fuel would be best? Natural gas or propane would be good. What about E85? How do you modify an engine to run on high percentages of ethanol? Higher compression or lower? I'm thinking it was higher compression.

Thanks again for your input.