Wood Gas Only

I’m rather new, but getting well versed in wood gasification. I live in Northern Maine, and teach Automotive Technology at the high school level. Building things is always been a hobby for me.

I have read that most everyone uses a “HyBrid” setup, starting on gasoline then quickly changing to wood gas. But I also see folks starting generators on wood gas only.

Are there any vehicles that are just wood gas fired, and what are the pros and cons of doing a wood gas only vehicle. Seems like you would just have to have a good flow of vapor to the intake to start it on wood gas. Might have to wait a few minutes to get it up to temp, etc.

Any input ???

It makes for quicker and easier start ups…plus you have the extra power when needed…if you know about wood gas you know about the power loss. Also you have a way to get home just in case you have a gasifier problem.

Hello Kenneth,

I have two trucks that I can run woodgas only and a third by adding a blower. If you will drop down a few threads and read 'dino cost". I posted some thoughts on the subject yesterday.

It is difficult to drive 100% wood but easy to drive 99% wood.


As I see it, starting it on wood can be a challenge, but once it gets warmed up, and the system is purged and gas starts flowing freely, it should not be a problem.

Another thing is that there would need to be a way to “Choke” the gas, by cutting off the clean air inlet at start up.

But if there is a problem with the gasifier, then I have AAA to get me home, but I do see the point of a HyBrid.

Hello Kenneth,

One can start up on wood gas each time but it will take some time to learn the procedure . If the gasifier has been heated up with vacuum motors the gas pipes may have air/oxygen in them. If the gasifier has been run and shut down the pressure may fill the gas pipes and push gas up through the air /gas mixer and also push gas into the fresh air/oxygen pipes (flooding)

Even with the best trained ear it takes a few revs to determine if it is too rich or too lean . When starting on gasoline the computer will adjust to the proper fuel/air mix and start the engine. I think with most motors the timing is retarded when starting and advances as soon as the motor starts . Wood gas will do much better if the time is advanced and by having the motor running it is advanced.

Gasoline makes sense as a starting aid, for short hops (under 2 miles), as a power booster, and as a fail safe - meaning all else fails it still runs gasoline OK; a non-woodgas driver can operate it, etc.

If you plan on running without a safety net, it’s similar to travelling with no spare tire, or no cell phone. You can do without 99% of the time. But there’s no reason to, and you’ll regret it when that 1% comes along.

Generator failure isn’t catastrophic like a truck that quits. If the genset quits, you’ll spend a day monkeying with it - at home. If the truck quits, you may be hundreds of miles from home.

If you really want to be a purist, build a truck like Wayne’s and just never use any gas. The great thing is, you can choose what MPG you find acceptable, all the way to infinity.

Building a rig to run either or both beats waiting on AAA any day.

I know what you mean by waiting for AAA,… Up her in Northern Maine, we are far out, at least 50 miles past the end of the earth. AAA may arrive anywhere from a few hours till maybe the next day “Latter is usually the scenario”.

I once had a Cat Motor Grader with a “Pony Motor”. You would start this pony motor, which was gasoline, run it 20 minutes and it would heat the water jacket on the diesel engine, then when it came time to start the diesel, it would turn over the diesel and get that fired adding diesel a little at a time. Was not a modern “Turn Key” operation.

But this set up worked, and you knew what to do. If you wanted to start a daybreak, then you started getting the engine ready 2 minutes sooner. Seems like this is what driving on “Wood Gas” is all about.

Maybe I will remove the fuel tank and make a small starting tank to draw from just for starting.

Good morning Kenneth,

You may not believe this but I have one . Anyone that has watched me go through the starting procedure can’t believe all the steps. The exhaust of the little gasoline motor goes through the intake of the diesel motor.

D-6 Cat 9U series


I’m extremely familure with that. Most likely has a D4600 6 cylinder engine. I can remember to process well. Wasn’t easy nor fast, but a lot better than using a shovel and rake !!!


Project vehicle for my Wood Gas vehicle is going to be a 1977 Ford F350 Four door Club Cab. Going to change it over to 4WD from 2WD. Back bed is gone, but frame is mint. Cab very restorable. Planning on a gasifier that sits a little lower next to the outside of the frame so it sits a little lower even with a larger hopper. Has a stock 400 CID with stock compression, but have my students building up a 460 CID with 12:1 compression (Better combustion), RV Camshaft and better flowing manifold.

Axles will be 4:10 ratio, with Posi-Traction Duel Wheels. 4 speed standard tranny. Starting with the truck restoration at school as a training aid, but gasifier is my home project. Looking to have a up and running unit by summer. I’m extremely lucky as my shop (Home) is better set up than our automotive shop at school, and it is 2000 sq ft, and fully heated all 10 months of winter up here.

Wow. That will be interesting with the new motor and higher compression. I don’t know if you can still run premium gasoline at 12:1. You might consider ethanol or CNG as your alternate fuel, those work well at higher compression.

Hey Chris, and Everyone

I will most likely plan on running a Propane Vapor setup from a forklift as the secondary fuel. This way I could get away from the EFI for this older truck and easily shut down, and easily started.

Even with the high compression and advanced ignition, this should work well. I have done my homework on a lot of this stuff, but still need guidance and advice. Like I tell my students, “You can always learn something new every day, even from a child”.

I have read all over the internet about wood gas use. Some just as a hobby,… some as they don’t want to pay for gasoline, and others planning for the doomsday scenario. Whatever the views of the individual, the same thing applies. We can all learn from each other. Propane cylinders can be transported easily, and won’t start breaking down (Like Gasoline) in as little as 3 months. I read somewhere that Propane can be stored for century’s.

Propane is almost as available as gasoline in a lot of the country. Some Gas Stations, Wal-Mart, Hardware Stores, Etc. Plus the Vapor Carburetor can be used as a control for the air intake. My plans are to be able to use the truck for work, travel with the family (Reason for 4 door cab), and to use wood gas. Not to run to the store for a cup of coffee 3 miles away.

My opinion is that something is in the works, as far as the country being in poor condition, but who knows. I am lucky enough to live way, way out in the extremely rural area. Our pantry would feed us for a long time, and my farm would feed us even longer. Have lakes to fish in, can hunt, and farm. Own over 100 acres of woodland, and burn wood. But this isn’t the issue, having a backup is what is needed, regardless the reason.

Hey Kenneth,

I am old enough that I have owned and operated a diesel that had a small carburetor on it for starting and warming up on gasoline and low compression then switching to high compression and diesel.

(TD-14 International)

Howdy Wayne,…

Yep,… Me Too,… Farmall SMD “Super M Diesel” tractors was the same set up. So were the International UD series of generators. I lots of experience working on them, but I won’t admit to my age. Ha, Ha, Ha,…