Producer (wood) gas : LUSENET : Freedom! self reliance : One Thread

Has anyone converted a small gas engine (3 ~ 8 HP) to run off of producer or wood gas?

The whole concept intrigues me, and I really would like to get (or build) a generator to keep the batteries charged and maybe run the satellite dish reciever and the small tv. But at the same time I don't want to buy and store that much gasoline.

-- Eric in TN (, September 17, 2001


Hey Eric! Runnin an engine off of vapor is purty well the same as usin propane. Those conversions are simple and can be used on most any type of 4 cycle gasoline engine. Different adjustments will have to be made but that's not difficult with a conversion that's available. I converted my 6 hp Techumpseh to run on l.p. Works great. I thought about usin charcol gas, carbide gas etc and decided no more than it used I'd go ahead with l.p. It's not that expensive to run on it and the gas is always consistant where other types of gas may not be consistant and that would cause real headaches keepin it runnin. ole hoot. Matt.24;44

-- old hoot gibson (, September 17, 2001.

As far as I know there is virtually no engine work to be done. Make the gassifier, supply the vacuum with the engine intake thru the carb, and install a butterfly valve to atmosphere in the vacuum line. Start the engine on gasoline with butterfly valve all the way open. Lite the gassifier and very gradually close the butterfly valve till the gassifier is fully up to temp. while keeping the engine running. At that point shut off the gasoline supply to the engine. Pretty simple.

Remember tho that there'll be a power loss, about 50%, in the engine due to the lower btu content of the producer gas. So if your starting with a 5hp engine, cut that in half to 2 1/2hp and divide that in half to give you the max KW you can expect from the unit.

-- john (, September 18, 2001.

I apologize in advance if this is a double post. This puter's been quirky lately.

I assume Eric you're interested in producer gas because its renewable and locally available as a homemade fuel.

A system I worked with worked like this. The carburetor intake was hooked up to the "outlet" of the gasifier. To start the whole thing up we'd first start the engine on gasoline. There was a butterfly valve on the line connected to the carb mentioned above and the butterfly valve would be fully open to permit air into the carb. We'd then ignite the gasifier and very slowly close the butterfly valve to assure a vacuum going thru the gasifier. Once the gasifier was up to temp we'd shut the gasoline supply valve off and the engine would run on producer gas.

Producer gas isn't as "hot" as LPG is. It contains fewer BTUs so you have to compensate. Assume a 50% power loss so if you have a 5hp motor you'll only have 2 1/2hp available on producer gas. Then as a general rule of thumb assume 2hp/kw. In the example given above you'd have a 1250watt capacity with a 5hp motor run on producer gas.

-- john (, September 19, 2001.

Thanks all for the replys. sorry it took so long 4 me to get back ta ya'll, but the wife is sick with a cold, the 8 year old is catching it, and the 3 year old has the croup and a sinus infection, so 'puter time has been limited.

-- eric in tn (, September 24, 2001.

we The "Tata Energy Research Institite" in India,working in the area of power generation form very long time.We have experience of more than 1,50,000 hours of running gasifiers,on different biofuels & more than 500 hours on engine,succesfully so if you are interested please send me the further requirements loocking forward for your reply with warm regards mohit

-- mohit pushp (, February 18, 2003.

Sorry I do not have an answer to your question. I would like to know the easiest way to purify producer gas so as avoid problems in the engine. At the university of Dschnag in Cameroon we have a lot of problems running engines on producer gas due to impurities.

-- Tangka Julius kewir (, February 28, 2003.

I think what would solve a lot of running and performance/longevity issues would be to make the gas and be able to put it in pressurized tanks. It could be filtered before going in the tanks.....if in the case of using it for a motor would just have one or more tanks with you.....eliminating the "on the fly" conversion. This method would also make wood gas more readily available for the general public as youcould have wood gas refilling stations just as you now have propane refilling stations. I don't know the legalities for everywhere but I think in at least some places in the US the authorities would not like someone operating a firebox or furnace apparatus in a motor vehicle on a public road. So, does anyone know how someone making wood gas at home could compress it into their own containers/tanks?

-- Brian Holt (, March 10, 2003.

Check out my website, It is a must that I offer a wood fired engine design to go with BasiCar. I am initially attracted to steam power. Strictly non-prophit effort. All help is welcome. Bob

-- Bob Essert (, April 29, 2003.

I have another question? What about using another material for the fuel? In my area there are a lot of old tires for instance. Do you think a good process could be developed to handle that fuel? It would solve a waste problem and gain some fuel to boot. Of course I suppose something would have to be done to handle the sulfer in them, but aside from that they are very high in energy content.

Please also repeat any answers to my email address as I don't often come this way. I just ran into it doing a little web research. thank you all very much.

Mark (grgeek)

-- Mark Jones (, June 09, 2004.

Ok....a couple of answers here, yes you gould build a gassifier system that runs on OTHER things than wood, tires would be fine to a point, the reaction you are looking for is pyrolysis , do some searches on tire pyrolysis a, although this is for LARGE scale operations, but yes it would work and probably much better than wood, as tires are loaded with hydrocarbons and dont forget thats what youre after the hydrogen part, as well as the CO ,

Second many posts have suggested that you will be looking at as much as a 50% power reduction , that is true BUT avoidable. Ok part of the decrease can be made up again from the increase of compression, there are 2 ways to do this, change the volume of the combustion chamber at TDC (top dead center), sometimes this is done by "shaving the head" taking of 20,30, 40, 50 thousandths whatever, I personally DO NOT Like this method on Flathead engines, you are better to deck the bloc itself, BUT beware you will need to take some off the valve stems or tappets to compensate OR supercharge the engine, on small engine (under 80 or so CI) you can use an "Air Pump" that is part of a cars emmision system, they have a very low drag and put out a good CFM rating for their size and power requirments.

The other thing is TIMING , now opn most all small engines this is fixed on points type ignitions, I suggest modification of electronic aftermarket ignition modules, what you are going to want to be able to do is advance your ignition WHILE switching from Gasonine to Wood Gas, just a few degrees but advance in the spark will greatly increase the performance when running on wood gas.

Beyond all of that something that might be of interest to anyone considering pyrolysis gassifications is the immortal Smokey Yunich , in 84 or 85 popular hot rodding or HotRod I cant remeber he had a Fiero converted to run of gassification of gasoline, he wasnt buring the gas itself but rather all the componets gas breaks down into under heat. An amazing concept, using gasoline I mean. I spoke with Smokey about this design several times the last time he said although he was considering building a modified version Crane Cams had bought all the patents he had on it so it might be worth looking up.



-- Chris Wertman (, June 10, 2004.

I just stumbled onto this site and noticed your question. I had this same discussion today, and wondered if the compressor in a refrigerator would pmp the wood gas into a p;lumbers tank--store it for use as you are hoping for?

I'd welcome any e-mail or comments. I'll send you copies of the pictures of my gasification system.

Operating as we speek August 2004

-- Ned Towle (, August 10, 2004.

Ned! I'd like a picture of your device. I'm workin on my own at present but am far from bein done.

I don't know why an OLD fridg compressor wouldn't work. I've used'm for vacume pumps before in refrigeration, a/c work. The ones we used to use were from old fridgs and not the newer "pancake" types. They may work but the old'n did a good job. oldhoot. Matt.24:44

-- oldhoot gibson (, August 10, 2004.

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