Donor vehicle help and compressed woodgas

So this my options for donor vehicles right now. I have a 93 Chevy 3500 with a 350 “throttle body” this truck is a truck I use to haul wood on a 16ft trailer for my tree business. I was thinking fossil fuel for tree work and wood gas for cruising on days off. Of coarse I would have to try wood gas at work out of Curiosity and testing purposes:):stuck_out_tongue:… or an 80’s Chevy half ton with a straight 6 engine. Not sure if this is multi port or not but will post pictures for help. This isn’t my truck but it’s in my field and I can buy it cheap if that’s the route I should go. I understand bigger engines is better but this is where im at right now. If y’all think neither one of these vehicles would be a good choice I will go with my old lawn mower for now until I find a better donor vehicle. Which would probably be a spring time thing when tree work pics back up. So that’s it just looking for some pointers.

Compressed wood gas. I know this has probably been talked about a lot. I tried searching on this site but only found one conversation. What I’m curious about is would it be possible to compress wood gas into a big propane tank “like a house propane tank” and run a furnace with wood gas? The conversation I found was talking about tar being a problem I believe. If that’s the case, is there a way to filter it enough where the tar would be completely gone and that work?


I’ll post pictures of the donor vehicles. Here’s my wood pile as well lol

This is my hard wood for heating my house and garage

My wood chips pile. Hoping these could work in a gasifier


Number 1. My opinion on the compressed woodgas. If you are heating with wg I don’t see where the tar is a problem. Many people have messed with compressing it but I don’t know of anyone who has stuck with it. They used canvas bags on top of buses in Stockhelm during the war but you would not call that “compressed” gas to the extent you are talking.
Number 2 Choice of truck. First I know of very few gasifiers that use wood chips We have one member who builds them for sale but they are very small. Chips are not labor free for gasifiers. A couple of fellows on here who do work with chips have to sort the chips to a certain size and them they have to be thoroughly dried. ( tree limbs have to be chunked and dried-- a tossup. )
The truck to choose— If you are serious about this, the 3500 is your best bet. The 350 is a little light for a “work” truck but there is a solution to that. A truck can be run on wg and when you run out of power or speed, you can “drizzle” a little petro in to boost everything up. When you reach the speed you want or get the load delivered, turn the petro off and run on wg. I would not build anything other than a Wayne Keith design and this will require time and a reasonable amount of money depending on what you can obtain in the used items that are needed and suggested.
The Chev 6 would be a truck to experiment with and get your feet wet in DOW. How much would it take to get it road worthy right now??? I probably would not put the time and money into a WK gasifier for that. Start out with a simpler Imbert or something or you could ever try the simplest which is a charcoal. Compared to wood the charcoal is accepted to be a little more labor required, but if some of our charcoal experts think like me, you could make charcoal out of chips easier than making it out of wood chunks.
Final note; all gasifier do require extra maintenance compare to petro. TomC


Tom thank you for your reply. As far as the older Chevy I’m not sure. I know the truck runs but haven’t looked it over much past that. I can buy it for $300 maybe less. I would really rather do my 3500 and wish it had the 454 with MPFI but if it will work ok, I’m more than happy with that. My next vehicle will be exactly whatever works best for gasification. I’m going for Wayne’s design with whatever new upgrades I’ve heard a little about for sure and am waiting for the book to arrive. I’m gonna try to salvage as much of the build as I can. I’ve already started to collect a few things. And I have several 50 gallon cans and some smaller one’s already. Idk what all it calls for yet of coarse until I get Wayne’s book so I’ll know more after that. That’s interesting about turning the chips into coal I’ll look into that. Not sure I wanna do the coal way for awhile yet though. I love the idea of using wood. Yeah Tom I’ve just been curious if anyone has filled a big propane tank and used the gas for a furnace to heat the house. I’ve seen a few YouTube videos where they fill the small tanks. That’d be cool if so. Be something I’d do for sure. I already heat my house with a forced air woodstove but it’d be sweet to have the option to use the furnace on days when it’s not real cold and you just wanna take the chill off. So i have a question. Is it ok to have the gasifier going and the truck not running for an extended period of time? Ive been wondering about that. I’m ok with a little maintenance. I know it’s not going to be as easy as gas but it will be worth it for sure! :slight_smile: seems like everything I own needs a little extra maintenance anyhow lol. Thanks again Tom!


Hi Elijah,
compressing wood-gas is not the best idea for two main reasons.
First, it contains poisonous carbon monoxide. No smell, no colour. In a gasifier, there is a slight underpressure due to the sucking action of the engine. So, small leaks let air to the gas pipes, but no gas is leaking out. Only if the engine is shut off. There have been a number of deaths related to this during the wood-gas-days of WW2!
If the gas bottle is leaking you probably wouldn’t notice it until too late.
Only use wood-gas outside, burn it directly in a stove or an egine. If it is possble that some amounts sum up, for example garage, use a CO-detector.
Second, the heat value per volume is quite low. You can’t liquify it with pressure like LPG. The energy you need compressing it is more ore in the best case the same amount you store in the bottle.
Hope that is helpful for you.


If l remember right, at WW2, there was about 1 casulty per day from wood gasification.

Allso, woodgas is unstable and breaks back to soot and CO2 over time, pressure elevates the process.

We like to say the gas is already compressed in wood. The gasifier us just a “carbourator”. Actualy, in German, a wood gasifier is called a “wood carbourator” (Holzvergaser), right Til?


Yes that’s right. But in german, the carburetor is already called gasifier (Vergaser) or evaporator, because in the very early days of automobiles, the gasoline was actually evaporated in this devices before fed to the engine.


Think baby steps.

Learn to focus on one goal at a time, unlike me. :wink:

Maybe a gasifier on a trailer.


Hi Elijah, If I recall correctly, Wayne said that he tried throttle body inj., and it had problems. Maybe Wayne will address this. (don’t want to speak for him).


The main reason I don’t like a TBI or carb is because of the carbon build up that will happen over time in the intake manifold. With a MPFI it is real easy to burn out. With the carb and the TBI it is a pain.



I remember the day’s… untill 1960 - 1980 the Gazometers were everywhere…
The coalgas or Towngas was piped into every home… guess what the content was ?
Yup Carbon monoxide… only replaced by natural gas because of the profit…

Those day’s every village had a coal gasifier… why not return to those day’s but now with a wood gasifier ?

2 cents: compressing woodgas for household does cost energy for the compression… about doubling the cost of energy compared with straight gasifying.
However, if making charcoal and using the heat from that process for heating house, subsequently compressing the evaporating gasses in a tank, you end up with pure gas, no dilution from nitrogen, making it a feasable thing to do.

The charcoal would then end up in a generator, or car…

A good gasifier nearly produces tar free gas, some very good gasifiers are real tar free…

A good automotive gasifier, as the WK type, is always the best choice, to learn, to observe and to learn more…
But you’ll need a lot of lemons to get the grin of your face when passing the petrol stations…


Hear hear…

and yes… if all of us did learn from the old folks , how to lite the fire with little more then a match and some kindles…
Nowadays if the batterie is empty people would freeze to dead, not being able to do things without a smartphone…
(surprise … a smartphone can not start a bonfire to make you warm )

I learned from those older people… becoming aged myself :grin: the best stoves where always cleaned and refilled before litting them up, they never let you down…


Hi Koen,
yes, you are absolutely right. Town gas consists mainly of CO, and there have been casualties and suicides because of this.
On the other hand, the town gas network was on low pressure and thus easier to maintain. I agree that we could run a town gas network with wood gasifiers. Gasometers as storage.

But this topic started with compressing wood gas to higher pressures into propane tanks. And that doesn’t make much sense.


With all that chipping I would say you are a good charcoal candidate. Most of the raw wood guys do chunks for their consistency, density, and ease of processing. Charcoaling is time consuming and an extra industrial process but it can greatly simplify your build cutting down weight on the vehicle… It’s a “discussion” as old as gasifiers probably. I think most of us would say compressing is a non starter due to all the reasons laid out above.


If I had that pile of chips I would use the heat from the composting to heat my home and shop.


I bought a built truck. old, carbureted. If you are going to invest in woodgas, I suggest you stasrt with a nicer, newer vehicle. Unless you want to build several. There is a lot of time and money involved. I have also considered Jeff’s trailer idea myself. Maybe we’ll do that after the charcoal system is finished. Sell the other truck and buy the Dakota. There is a thread on here called “deals on wheels” It has some good options. I think there’s a white extended cab in Gadsden AL right now. …Why is tree work slow there? It’s booming here.


Hello Til, I too am new to this site and am enjoying reading and watch you guys. So My two cents in this discussion is as follows. I see too many obstacles in straight wood gasification in comparison to charcoal gasification. I just made my first batch of charcoal with an indirect method kiln made from a few pieces of pipe and a tight 55 gal barrel. Additionally there is a fellow on you tube who shows how to compress the gas into a propane tank. Seems easy enough if you want to do it. Here is a link: Pretty new here trying to see if I can post a picture of my Charcoal retort/kiln

Just imagine a four hour burn and all those chips turned into charcoal ready for you to turn into CLEAN gas for your truck or whatever. It does take about 3 times as much wood for the fire than you turn to charcoal. And that my friend is where the discussion will begin. LOL

Hope This helps answer your question Yes it can be done is it worth the extra trouble?? That is up to you. The down side is how much can you get in a tank safely.


Waste wood chips might be too fine for charcoal. I made some good engine sized char from sawmill chips which tend to be more in the line of flat chunks. I sourced some road crew chips but they would only do for biochar. If you are running your own chipper maybe it could be set to a coarse size?


Regarding compressed wood gas, that has been much discussed on this site. Yes, it can definitely be done. There is a bit of a question mark yet about how stable it is at high pressure over time, but there is a YouTube video of a fellow who stored gas over part of a winter. Given the low temperatures it may not be a completely fair test (reactivity proportional to temperature), but more or less it demonstrates.

But… Wood gas is not efficiently compressible like butane or propane, which could be likened to mousetrap springs. Also, wood gas has a low calorific value due to nitrogen dilution. So the energy required to compress it represents a significant proportion of the energy of the gas.

So the conclusion is that compressing wood.gas can be done, but is not practical in energy terms, but may serve for special applications, recognizing that the efficiency is practically nil (ie, cutting torches).

Retort gas, as you seem to be aiming for, may be a better candidate, as the gas isn’t diluted, so is more energetic.

My suggestion - aim for the proven “gasometer” technology. Basically a large gas bag, weighted at a few pounds pressure, minimum energy input, maximum functionality. For stationary applications bulk isn’t such a bad thing.


I think you hit the nail on the head Garry. Compressed gas may have it’s applications, but does not seem worth the effort for long distance applications in a mobile environment. I am looking into a small stationary set up for an engine generator and see where that leads me. I like the “simple” charcoal retort so far for starters. Thanks for the feedback.


JohnL there once was a youtube up on a SE Asia stationary engine/electrical generator being ran off of woodgas stored in big overhead clear polyethylene tube/bags. I recall only a 45 minute running time?
Past the combustion passed trough air/nitrogen energy dilution is the fact that CO gas with only one carbon can never match the energy density of any of the multiple cross/long chained fuels like butane, propane, methane (CH4!). Let alone super carbons/hydrogen’s rich gasoline or diesel fuels.

Butane and propane CAN be with just a wee bit of compression and comprehensive heat build up removal condensed down to a super-dense easy storeable liquid form.
Methane? Woodgas? Charcoalgas? Thousands and thousands of pounds per square inch and the containers to safely store that and it still cannot match energy store density of any fuel able to be liquidfied.

Ha! Why many of us will “work” for the raw woodgas . . . the live made ready to use CH4, steam vapors components to go along with the woosie H2 and low energy CO. Surprisingly in a piston IC engine the extremes of each of these balance each other out.

Blended is better in whiskeys and engine fuels.
tree-farmer Steve Unruh