Hi All
I wanted to have a place to share some of the “small” engines we have seen and experienced successfully woodgas ran.
Whole bunch of people now woodgas ran the years produced 1976 to early-2000’s Single Overhead cam Ford I-4’s in their different ignition 2300 and 2500 cc configurations. Works well. Ever wonder how much actual power potential these have as a stationary 1800 RPM gen-set?
Gasoline 36 shaft horsepower (27 kW) mechanical
Natural gas 33 hp (25 kW)
Propane 38 hp (28 kW)
These are Ford factory ratings on thier LRG-425 LP engine used in a certified 20 kWel Telecom system. Full data at 3600 RPM with pictures was put up here: http://www.microcogen.info/index.php?topic=2670.msg30547#msg30547
Both APL/GEK and Victory Shop have evolved to the Kubota DG 972 3 cyclinder natural gas engines. Why? They work very well and Kubota wanted this usage to be developed and publicized. But yeah, couple of three thousand dollars a unit new.
Hey Chris/kymetro! Wanna read about a fellow took one of your Geo Metro engines, made a 4 kW home gen-set (propane fueled), a made a home built electronic govenor system? http://www.microcogen.info/index.php?topic=2662.0
Starts at Relpy #10 and goes on from there. Fellow who built this put it up as a $2000. COMPLETE system challenge point.
He is now here a member here wanting to learn how to woodgas fuel it.
Then there is Daniel/foxridgecampground with his 22R SOHC Toyota gen-set. Matches Bruce’s in Iraq Toyota PU and the International Geographic/JohanL. built Toyota pickup.
I personally do like a pushrod overhead valve operated engines much better for the “weak link” of a bent pushrod when a stuck valve incident may occur. V-twins are my favorite smallest engines in these. Experience now with Kohlers and Genracs V-Twins. APL/GEK has now logged many hours on V-twin Hondas and Kohlers.
In my opinion now best to 2-3X oversize the engine versus when on gasoline or propane;
Down speed operate it below 3000 RPM just like Wayne and others overdrive and down speeds their vehicle engines on slow combustion woodgas;
Stick with multi-cylinder engines to help even out the intake pulsation’s. The woodgas gets easily push around in waves screwing up even delivered air/fuel ratios;
And MUST have electric starting!! This frees you up to fiddle with the gasifier/mixture stuff without huff and puff hand pulling/cranking passing out. Allows you to build useable woman, older responsible child capable system from the get-go.
I could go on and on but enough for now from me.
Others experiences?
Oh, and you can tell your Geo Metro friend that if he decides to go with woodgas, the compression ratio can be raised to 12:1 or even higher without issue, these are non-interference engines and there’s metal to be shaved. Here’s a thread on the Geo Metro Forum about a successful 12:1 engine: http://geometroforum.com/topic/4286813/13 [start at post #187]
Hey Steve great to see some posts about power generation. Whats everyones thoughts on a scaled down Keith style build for smaller less heavily loaded engines. I`m thinking about a 20hp twin Briggs off of a lawn tractor.
Best regards, David Baillie
Not to bomabard you from all directions Steve, but how about a 15HP thumper with hydrostatic drive… think there would be enough rear wheel power to make a wood chunker ? I have no idea of the specifications for the hydrostatic pump or how the rear wheel torque or PSI is rated, but I want to make a chunker similar to WK’s, but using this small tractor if possible. This one has electric start, a 12v electrical system and output shaft on the front that could drive a generator too. It has points style ignition though… would I need to convert to an electronic trigger off the front shaft? This would probably be my first engine to try to run on woodgas since the mower deck is shot and I have been keeping the tractor for a R&D project like this…
Hey Steve,
That is more or less my plan too. 20hp Lawn tractor, wood gassifier, turning an alternator, secondary battery bank in the greenhouse backcharging the house through an inverter then a 24 volt charger in the house seperate from the inverter charger setup. The charcoal 110ac I built works fine but those small fluctuations in the AC drive me mad and the ever so slight delay between load change (pump, dishwasher, fridge) can make the inverter/charger kick off. It’s one of the vestiges of inverters being derived from RV units I think. The makers seem to think that you have unlimited AC when you plug them in So you need 3 times the AC generator you otherwise would use for battery charging just to handle peaks therefor more fuel usage. I figure I can do all those conversions and still come out ahead in terms of efficiency. Off to the salt mines, David
I forgot. If we can figure out a sizing for it I thought of building one for my real tractor. A 1951 Ford Ferguson tea20 4 cylinder 28HP with pulley at the front for turning an alternator and pto on the back. would be perfect I think; the engine is a tank and easy to work on huge air intake with easy access. Steve, what should I be reading to figure out sizing the main unit? Need some advice.
thanks, David
My experience with the small ones is that they are very picky. The small dimensions ask for very well insulation which is difficult, because the ratio radiation surface/volume is large compared to bigger gasifiers. And small wood is seldom good flowing blocky, but often flat, sharp and light. Resulting in an intermittend flow.
I did not test it yet, but using dimensions as if the engine were much bigger and putting more effort in heavy hearth insulation would be a better way to go. Heavy insulation allows a larger turndown ratio. Of course the power demand of the small engine has to fit into the ratio.
Hi Steve, I got a used car the other day that has a cute little engine in it. EFI 1.6L DOHC . Not sure what the power rating is for this on gas, but it seems like it could make a decent, fuel efficient engine to run a genset or do some other work around the house. Of course, I cant rip it out yet. This is in my Daughters first car : (
I run a DOHC engine on wood gas and never again. It runs good, but like Steve says it is too risky. Plastic intake manifolds also present a problem because they run colder than normal and they are difficult to clean out the soot after running a few thousand miles. I would recommend against this type of engine for wood gas unless it is an emergency.
Hey Steve,
Great article too much red meat reading for right now but I’ll file it away. As an off grid house lightning is one of those things that can ruin you. I assume you would have lightning arrestors in your own place? They are not code here yet but more and more common. I prefer the off grid ones myself just a one time use fryable unit supposed to be more sensitive then the resetable types you see in on grid places. I have even heard of a lightning arrestor installed on a dedicated line for electronics. Probable no good for a direct hit but a near miss maybe. I suppose it was the utilities that got zapped not you? Sure does drive home the whole self sufficiency thing though don’t it. My joke is that I can only tell if the power is out by my neighbours knocking on the door to take a shower or fill water jugs… Projects are all on hold right now til I can wittle down the backlog of work that pays money…
Best regards, David Baillie
I loved the way Ed Stoller made pickup coils on his wife’s sewing machine. Posted pdf files back in Woodgas but have been updated since then - current link is enginesandmagnet.com (http://home.earthlink.net/~edstoller/index.html)
i.e. electrical storms… had a hit that killed a 36" pine tree off the back corner of our place last year, and 2 strings of mini Christmas lights - packed in a box with the tree on a shelf in the back store room - were all fried. The filament was still in the bulb, but if you tapped it with your finger it would fall apart. Craziest effect of lightening I’ve seen. Lost 2/3rds everything else electronic… William in GA
Hey Steve
You stated problems with single cylinder engines running on gasifiers. Is the pulsations screwing up the cycle in processing of the wood? If this is the case there could be a chamber of X volume with tuned orifices of Y diameter on the inlet and/or outlet of the chamber to filter out the pressure waves. Pressure to me is any pressure is relative to intergalactic pressure. Aristotle goofed when He stated “Nature abhors a vaccum”, is only relavant on this third rock from the sun.
Seriously the pressure waves should be tuned out to prevent them from reaching the gasifier, and help give the gas a good push into the engine about the time the intake valve opens. Of course this will be rpm dependent.
Hi ErnstG
No problem is/was not with the pressure waves back into the gasifer/producer. In the hearth charcoal area pulsation is actually beneficial for clearing the char of surface ash.
System pulsation does screw a bit with effective cyclone separation. This is easily worked around with a settling chamber separation system instead.
Yeah. I thought it would be easy on a single cylinder four stoke to tune in some intake manifold induction length ram charging. Worked OK on the air side. Terrible on the gaseous fuel side when sucking through the restrictive char/fuel bed of the gasifier. Reverse pressure waves would stack back pulsation’s of fuel gas to the gasifier bed restriction point and the reflected pressure waves of fuel would never co-ordinate with the delivered air pressure waves for good consistent air/fuel ratios…
I did work on this all of the winter of 2010-11 with different tuning lengths and air and fuelgas side pulse dampening reverse flow edges and restrictive balancing air filters.
Bottom line was unit had always worked just fine through the original restrictive gasoline carburetor venturi restriction with stupid simple mixing in the original air cleaner housing. Just choked back to 1500-2000 watts out of a potential 5500 watt electric output rated unit.
Eliminate the venturi restriction with wide open like fuel injection tubing and I could manually tune and hold 3200 watts load continuous. All of this was without engine compression, valve or ignition timing modifications and at a demanded 3600 RPM +/- a 150 RPM for 60 hertz fequency control to be able to operate consumer electronic devices.
Problem was with electrical load changes all of my affordable KISS mechanical pressure balance actuators for multiple cylinder control ideas would NOT work without a steady intake vacuum. Sure, sure. Could have been high speed electronically controlled. But $2-300. of electronics (retail) on a $600-800. Sears/COSTCO/Harbor Freight gen-set in addition to the same (retail) in intake manifolding, valves and actuators did not make sense.
For the same few hundred in electronics for off the shelf DC to AC inverter(s), then simply engine over-sizing, and now spinning “I do not care about RPM” high output DC automotive alternators put “Replace with known good part” user KISS back into the system package.
Active woodgas fuel producing makes things not straight forward as compared to gasoline, LPG and CNG techniques on small engines.
