Leitinger wood gasifier

Hey Kristijan

I believe your gas is asking for a motor :grinning:


Looks more like the first wood fired rocket to me :grinning:

Beautiful Flare. Looking forward to filter results.

1 Like

Hi guys,


Jan, the first is just a old rusted chimeny pipe, about 12cm wide.

So much work lately, been loging for the last 3 days, about 10 cords of beech firewood prepared for a customer. Its, funny, Once you DOW, you look at every log and limb with deep respect.

Painted the new asembly today, this means its near to DOW :grin:


Kristijan, I feel I can speak for those who have been following your thread. We are waiting anxiously for your first run with this new Gasifier rebuild. It aways exciting to see the engine running on woodgas, no matter where you live on the earth, and also get to share in your achievements and learn. The Internet is a wonderful tool for this, it’s like being there with you. DOW.



i posted this in the topic Oilbath filter
using this on the most of my outgoing gasifiers and on my car’s

1 Like

We are still talking about charcoal gas right? Man l love that black gold. Wood is a nother thing…

I was thinking to put a oil final filter on, in the engine compartment, but not so much for the filtration, more for the purpose of lubricateing and rinseing intake valves, in case traces of tar start to produce. A cheap engine oil wuld be filled in, with a purpose of some of it escapeing with the gas stream.

Just a thod thugh…

Hello Koen,
Forgive my ignorance of the vehicle gasifier system. On my imbert gasifier the final filter is at the end of the gas cooler before the gas enters the engine. My filter also has a sort of catch basin for moisture getting through that far. It’s just a thought but there could still be moisture in the gas right after the cyclone seeing as how it is still quite hot. Even so I would include a drop down pipe(with draincock) just before the filter to catch any liquid water carried through with the gas. Just a thought.

Hi Pepe,
To give some idea about temperature and moister; 1 kg air at 20ºC could contain 3 grs of water or 1 gr at 30% saturation
Now, 1 kg air at 80º could hold a cup of water but still you would think it “feels dry”…

Meaning only, that to get the moister out, you’l need to cool it down as much if you can/afford.
Cooling it down below ambient and only before the final filter lifting to ambient could do great to keep the filter tissue “dry”

It all depends the system that can be build… the physics will be the same, the results predictable but differ from system to system.

If your gas has ambient temperature and ambient moister level, thats perfect to go with, but not easy to achieve :wink:

1 Like

Hi Kristijan,

Experiencing Tar is a difficult issue, it deserves a in depth case study to find out where it does come from, not only try to threat the symptomes but finding the fitting cure…

As Steve U and Max are telling, its now to find your correct balance in your gasifier to avoid the troubles, it might being the correct gasflow at given speed or given idlle… A moving vehicle is more difficult then a stationary system…

Try to focus on 1 item at the time, finding for each the min and max settings, then proceed to the next…

If you have tar or soot, before starting to filter it out, just find the reason before applying a cure…
One trick you can use: using a course aquarium sponge filter, soucked with airfilter oil ( motor cross ) this will catch a lot of soot for a long time… it will not ad a restriction on your flow to much.

Tar is always difficult to catch, especially with different species wood used. Some Tar’s need a long hot charcoal bed before they are cracked, some Tar’s develop late, some Tar’s early…

The collection of Woodvinegar from my retort charcoaling system is teaching me a good lesson on that, maybe some of the things i test/build could be used for preventing tar in a gasifier system, who know’s… I will post some pictures later on, probably in its own thread


I agree.

My previous sistem was something l considered “tar free”. But a unfortunate occasion, posibly my fault (l strongly suspect a case happened 2 times, where there was a big cavity in the charbed, that l only noticed after lightup) or like JO sayd, useing pellets, produced tar to cause trouble.
It is those occasions l wuld like to buffer, in case thay might happen. Not so much for everyday tar elimination.

Anyway, HAHA!! Finaly DOW today!
Sure felt great to ride on the right fuel once agen. Althugh it was a short one, it was like a drug after a long regab :joy:
l finished the gasifier, the coolers, the filter (in hay mode, need to cast the venturi for the scrubber) and saw no reason not to test it out.

Long story short, the drive was like someone substituted my 109hp engine with a 60hp one, besides less power there was no hasitation on driveoffs after idles (the 30l hayfilter might aid to that) , the power is there when you need it (the big wide charcoal reserve/reduction zone), it run cool and strong, but then my improvised plastic pipe too near the gasifier melted and deformed (wich was expected… l just culdnt hold on any more :wink:) the dino was back on.

I realy need to make a video. Have to show you guys something that realy made my day. The WWII style air intake non return flap. The sound of it when the engine is idle on wood gas is nothing less thain hypnotizing!


Yeees! Intake flap video, complete walk around video, driving video and… We can never have enough videos.
Are you saying this gasifier provides more power than the previous one? How much more are we talking about?
Congratulations! :smile:


Hi, Kristijan!
Congratulations! I still try to keep my feet on the ground. But Drawings with measures would be of great value for comparisons!
Specially, is the firering now the only air route into the hearth? How many 3mm holes are remaining?


Jan, its a bit too soon to say but l might have squeeze some more hp out of the wood with this gasifier.
I think you were right before, my foot was to havy fot the privious gasifier, entring heater mode often.
With this one, the oxy zone is the same size, with smaller restriction, but the reduction zone is much larger.
I found water in the cyclone dust container after a 10km trip!
Allso, the first impression shows lower fel consumption.

Max, l agree on staying grounded. Like l sayd, those are first impresions.
I have about 45 3mm holes nozzle circle 20cm and 3 8mm on top, protrudeing in a nozzle circle of about 15cm. Shuld be enough penetration, plus the air is strongly preheated WK/JO style.

Allso, l like the hayfilters ability to catch moisture. I only got about a spoon of water in the engine compartmet condensation catcher, wich means l am les likely to draw tar poluted water in the engine-a occasion that did appen before on longer driives!

The sistem still urgently needs condensing hopper. But for now, a 25l bucket will have to do the job :blush:


Hi, Kristijan!

Thank you! Full documentation will feed a long discussion…

Yes, I think our hearts are a bit on the small side. I like to run around 2000 rpm, which is also where I seem to get the best tourqe. If I shortly reach 3000 rpm (right before shifting after a redlight) I pull 30 in H2O even with a perfect 3:1 vacuum ratio. On the other hand idle capabilities are good.
Yesterday I was delivering firewood all day (25 mile roundtrips) with Rabbit and trailer. I didn’t have time to prepare food for the nightshift at the mill, so I stopped by the drive through and idled for a good 10 min. Out of the cyclone temp went down to 80 C but I could drive off like nothing happened. I’m glad you put some effort into the preheat on your new build. I think you will discover it cures the “get going hesitations” even more than the the hayfilter volume.
I’ll get out now and make a quick cyclone and condensation dump before fireing up. It’s been too long.


Congratulation!!! You amaze me how you can bend the rules and come up with something as good or better than most. The idea of a ring with 30 small nozzles ( holes ) and 5 larger nozzles on a separate plane just is not covered in the books You obviously have a better knowledge of what is going on in each step of a gasifier.
Couple of questions;

Are you saying the car drove like it had 1/2 the hp it had on petro?? Later you say " you squeezed more HP out of the wood with this gasifier" A little confusing.[quote=“KristijanL, post:875, topic:2677”]
plus the air is strongly preheated WK/JO style.

What is your preheat system? Mr. Wayne’s is quite complicated fins and channels along the outside of the fire tube. On JO’s as I understand it, is a tank around his cyclone and then I thought the heated gas went to the engine, not heated air going to the gasifier. I am in the process of removing the “air” pre-heater because it added so much weight. I am wondering if I am going to regret removing it.
As Max and JO shave said, “VIDEO PLEASE” ( pictures are good also ) TomC

1 Like

Hi, Tom!

With Kristijan’s consent, hopefully.

You seem to be a “Mary Contrary”, as nearly all others try to utilize what heat there is available to improve the process!

Reconsider! Or build it more convenient.

1 Like

Tom, my initial AIR preheat around the cyclone is only very mild. The major preheat takes place after that, when air enters the container surrounding the whole gasifier (1/8" void) before it enters the nozzle jacket.

Grrrrrr!!! When I have finally made up my mind to dump the big heat ex-changer, two of the people I respect the most, say I’m going the wrong way. Maybe I could encase the lower portion of the gasifier – below the hopper – with a container and feed it into the air intake. I have had insulation around the gasifier in this area. I’ll have to look at it but maybe I can put a mantle ( an English word I learned from Max) around that area and then put the insulation around that. First nice day we have had in months — got to get to the shop. TomC