Your Design CHOICES

I thought it would be good to have a dedicated topic to illustrate the How, for-Who, and Why any individual Wood Gasfier design element selected IS actually A CHOICE.
Ain’t no actual Laws to this.
Just general Principals.
Operating Principles. Principals of Practicality. Principals of limitations of current materials and fabrication techniques and abilities.

I will give just one example to get this started.
With a grate.
Without a grate.
Both work; and can be made workable.
Ha! Where do you want to spend your operational time, eh?
Occasionally servicing the below and above grate areas? WHY the factory Imberts distinctively had their three largish round external maintenance ports. To allow for this ashes/soots and fine char clogging maintenances. Pretty Practical solution to a ALL-Must-Flow-Through grate system.

Or CHOOSE to go Grateless.
Then system drawn velocity Must sweep all ash/stoots/fine chars out of the gasifier hearth to be externally separted out from the produced fuel gasses. Some seem to like having to downstream design for this. Then have to Maintnece slave all of that downstream elaborations. Not me.
Grateless makes you a slave to always having the internal system velocity to keep things from Not clogging up.
Right there you chose to have a gas-flow range limitation.
Chose to have a system slaved to the design narrow range of wood base ash percentage.

Me? Use a gasses BY-Pass grating system. A Command active moveable grating system. Retain as much as possible the wood released carbons in the active heating zones for highest percentage of to-gas conversion.
Ash is actually the remaining mineral core of the trees built up carbon chains. So ash in the hearth botton tells me success for my goal.
I want maximum engine driving fuel gases.
I am not a charcoal maker. My low carbons Doug Fir woods, always too wet, even if just from air humidifies, will not support handleably/storable charcoal making. Different climate. Different woods, and I would design Choose differently.
Above the grate clogging on my preferred center post supported Active grate system??
Shake it down. Over the grate edges spilling. Port scrape out, and remove. Manually separate out. Re-cycle, Re-Use the portions. Fused Ash found? Dramatically change Operation expectations. Operating too hot.

Choices see?
No dictated Laws. No you-must’s Always. No Pope dictates this. No Master dictates this. No Genius/Guru dictates this.
Results are your Guide.

Steve Unruh


Having a part “Z”


HenryB, later municipal and manufacturing plant systems solved individual gasifier systems maintenance problems by going-big and using parelled multiple units in cell-groupings.
Then one at a time rotated out of production for “maintenances”.

On, Your Design CHOICES I have been involved in the past 13 years with 2-3 groups that evolved past building from off-shelf and scraped sourced components to CNC intentional systems manufacturing.
The Best gasifier dimensioning then the Design driver? No. The best net usage of the 5 foot by 9 foot standard metals sheets.
And the whole system then once sales supported to being designed for standardized shipping pallet space/weights footprints.

And I am not criticizing these developers with these design drivers.
Vehicle wood gasification and the design Drivers are the space and weight demand that particular vehicle can accommodate.

So the Laws-of-Thermal Dynamics. The " Laws-of-Gasification". Need to be wide range accommodating. Not declared worshiped rigid Laws.
Guidelines. Area maps. Stay on the know trails. Or beat you own paths. Ha! Mountain ranges obstructions to travel past and there are only so many useable pass’s !! Only so many navigable channels into/out-of any estuary.
Steve unruh



Although interesting the Gas Plant systems you have both put up . . . .
These also represent Design CHOICES.
The choices here 1st was making and distribution out combustible gasses for Others, useages. Illumination. Cooking. Even heating.
So Large-Scale. And that means Investors (expecting returns) for the development, building and set-up moneys they have committed to you.
Now gas making for-sale Today, drags in many Safety and Regulating Agencies. Meaning even more single point keep from deployment blockages.
Back in 2010 I tracked over $200,000,000. of investor moneys sank into bio-mass Gasification energy systems 1990-1999.
Another $300,000,000 spent out 2000-2010. Where are the working system?? Sold/Boned off for pennies on the original dollars.
So Today it becomes far-far away from the science-engineering and even practical operation aspects of gas making.
E.g. when the stunting in-California Myth Buster fellows want to prove out the real/not-real of making rocket fuel from human shit they had to use a certified (in California) registered license solid fuel maker to convert their human shit. Televised publishing they could not just DIY their own shit. BTW, that shit powered solid fuel rocket did work. Very smokie.
Ha! And how they got that past the California Air Resources Board?? Do only ONCE. So- sorry. Apologetic for our air-sheet polution; I expect.

So the reality of doing any form of gasification today, for any purpose THIS is your first Choice:
Do this above board for others to use?? Good Luck with that, Chuck.
Do this for just yourself and your own usages? O.K. now. That is doable. Long as you can more-or-less keep your mouth shut.

Ha! Ha! I’d much rather address the Choices I seen, and operated, between squarish/flat sided builds versus always round vessels builds. Ha! You can operate the flat siders by the pressures popping of their sides! Lets you hear things happening systemwise.
Ha! Now automate that!

Automation insistent bound . . . ( a CHOICE. NOT a use wood demand must-do!!)
Just another Choice. Then make the possibilities done fit the Automation Shoe? Always driving you back to a standardized pelletized “fuel”.
Make a perfect wood pellet fuel system. Watch it crash when some dumb-dumb puts non-spec for ash % animal bedding pellets it. Puts their own made-up Municipal Sold Wastes pellets in it. Puts in their made-up consumer plastics pellets in it. This always happens.
Or go human manual control and then be wide open to the widest range of wood fuel input possibilities. Openly declaring that any fuel other than wood is a system goobering up. Dumb-Dumb . . . You made Gum-Gum. Now, you clean it up, and Learn to use wood.
To my mind the first Choice is catering to folks insisting on wanting served up ice water into the hells of their life choices. Lives of bought and sold into always wanting; more . . . more. All the while, Doing actually less, and less for themselves. Expecting served up to their waiting mouths perfect hamburgers made to their every whim, and cater.
The second: showing folks that Heaven on earth is DYI on all aspects of wood-for-power. For heating. For powers. For transportation.
Keeps you healthy, wealthy, and wise. The settling for; good-enough, way. That Less Is More. Ain’t no Perfects. Only Gitter-Done. Sweat it out. This is what gives value into lives.
Steve Unruh


I based my design choices on watching what the experts had done and using my materials to follow those principles. I tried one with all stainless we will see how it survives.


Ha! Ha! Ain’t no experts here Jacob.
Been burnt many timers.
And some just stick-too-it, carve-away’ers. Means once you’ve eliminated all of the woo-woo ideas what’s left will be the Practical.
And Practical will be different depending on where you use/live. And the using attention you are willing to commit to it.
Steve Unruh


I’ve just commented onto two different Charcoal making topics.
Just because I’ve tried, and decided Charcoal making and using is not for me does not decide this for others.
What I liked about the three fellows works that I positively commented on was that they were doing it hands-on in Practical ways applicable to anyone with source to fast grow shrub/hedge woods.
Freedom fuels makers.
Ha! is a universal language.


O.K. Another base choice we do make in wood-for-power, whether raw woodgasfication; or wood charcoal gasification is
The actual IC engine choice.

I know. I know. Most will say I had no choice but to use what I had.
Your “choice” was expectation limitations based on what you did use.
First be satisfied if you could just make the engine fireup an run on your made fuel gas.
Then gasifier fuel run with a useable power surplus.

Now here is where your engine choice will come into play:
How much of that engines original spec fuel power can you get on your DIY made fuel-gas??

A valves-in-block (flat head) engine and this will probably as low as only 25-30% of the engines power on it’s original fuel. Why? Torturous, flow resrictive air/fuel in passageways. Lower effective compression limitations. Shave the head to raise the compression ration will make the gases pathway from the in-block valve to the above the piston an even a tighter flow pathway.
And the largest possible combution chamber surface areas sucks the expasion heats out of the combustion before it can work powering the pistion down.

Now take the same wattage electical generator and have it driven be an overhead valve design and you can do more. Up to 50% equivency. I and Duch John were racing each other to ~70% equivalency. Ha! He consistently won. 3000 rpm power running versus my 3600 rpm was the trick of that imho.
A facory fuel injected OHV fuel injected design and do better yet. Yes. These do exist. in single and V-twin electrical gnerator engines.
It’s the no more flow restrition for a gasoline/propane/natural gas venturi. Wider, then intentionally non-heated straight in intake flow capabilty.
And most of the small engine EFI systems already do broad range cranking → idle → loaded power ignition timing changes. DIY Spoof-able.

See? Your engine choice was Expectations range setting.


Easy find currently available single cylinder EFI electrical gnerators:
a 7000 watt Ryobi at Home Base $999. USD if non-discounted
a Generac 8000 watt
a from California imported brand A I-Power 13,000 watt
So gasifier fuel one of these and then do get the 5000 watts electrical you expected.
Plus these larger unit s are dual 115/230 volts outputs. Most 5000 watt carbureted gasoline units are only 115 volts.

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Ha! Ha! I have expected the comment, “What about OverHead Cam engines?”
DYI gasifier fuel fed it really doesn’t matter IMHO.
True. Woodgas fueled you can tar up the intake valve stem (AND PISTON RINGS!) if you bodge the gasifier operation.
Charcoal gas fed you can carbons face deposit the valves killing the compression as a Charcoal electrical generator fellow just recently posted up.
So actual gasifier engine users have found what is more important is whether the engine is a hung-open-valve hitting the piston INTERFERANCE (valve bender) engine type or a NON-INTERFERANCE (free-wheeling) type.
Plus just how easy to access the valve stem and valve face to correct tared or carboned up situations.
OHC’s are always harder to valves corrections service. Flatheads easy to face service. A PITA to stem access un-goo.
Overhead valve rocker arm push rod types win out in gasifier fed serviceability.

And in a small electrical generator engine factory EFI lets you tag-along with the woodgasing benefits proven in this 21st Century by the many now EFI vehicle gasifer guys. Sweden. The Netherlands. Finland. USA. Canada.

The cheapest, quickest, most direct to results way to get going is to benefit from the positive, and negative, experiences of others.
Wood-for-engine-power fueling is actually 150 years multi-faceted experienced now.
DIY gasifing factory EFI engines is only ~20 years deep now. Still lots to explore here.
DIY gasifing the newest factory variable speed&power inverter-generator engine types is the newest least explored-for-benefits area.
The factory gasoline/battery hybrid vehicles are also ripe to woodgas develop.
Just DO use the larger engine types for your inevitable produced power set backs.

That genius "But I have never tried it! " (meaning it cannot but be Improved by Me) Types are real time losers to follow. Practical wood-for-power success requires a certain amount of humility gained from failures experiences. And, “That works. But is too damn complicated. De-humanizing. Tech-dependencies enslaving” experiences.
What you mean, Steve Unruh??
The Free demanding diesel vehicle users I know drive diesels that do not need DEF.
The no-care, not-aware, insistent on the newest, latest ,greatest diesel vehicle owners I know; dependecies buy a lot of DEF.
Pretty simple to see, actually.


Steve; your short hand is loosing me. “DYI gasifing”? “diesels that do not need ‘DEF’”? TomC

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hi TomC
Do It Yourself gasification, for use by yourself and those in your immediate care.
Diesel Exhaust Fluid. The additional must-use urea additive you must buy and supply for metered injection into all road diesel exhaust systems since . . . .?? These “modern” diesel vehicle electronically controlled diesel engine systems Will sence and scream loudly to the point of removing engine power and trans gears if you do not supply them.
Ask your friends, neighbors with within the last five years bought personal road diesel rigs.


Hey Steve I think you misspelled “DIY”. I didn’t know about DEF. I do remember when I was on the Town board and we planned to get a new dump truck. The dealer advised us to find the money somewhere and buy one before the new modles came out. He said the new computer system would just shut the engine down if you weren’t very nice to it. TomC


Thanks. Corrected.

Another base design choice set:
where will you get your woodgas information from??
Read EVERYTHING published?
Read selected works of previous efforts?
YouTube videos?
Forums trolling?
A published plans set like F.E.M.A; Mother Earth News, VesaM’s book plans, BenP’s book plans, Wayne&Chris’s book plan, etc.?
A pre-made, bought system?

Each one way will have it’s Pro’s and Cons.
The way you choose will depend more on you; and your way of thinking; than the actual validity of the material presented.

Me? When I decided to pursue woodgas for engine shaft power (to make home power electricity) back in 2006 I intentionally for two years just would use Internet sourced information. I wanted to see if Google-Info-the-World would really work.
It did not.
At least half of my first two years was Net/Google wasted chasing down woodgas fairies, woodgas myths, and high change-the-world woodgas social false hopes.
The best I got from that time period was references to the actual published books.
One by one, I sourced, and bought these books. Much, much better for me.
Ha! Then spent the next two years wasted trying to make actual heating stovewood firewood stick forms work not going through the chunking step. And pursuing a mass-thermal approach to wood into fuel gas making. Very, very difficult. Very heat conversion inefficient overall.
I did learn much though.
And that actual learning involved making (by invitation) others gasifier build-ups function. And that was from the books having studied the needed internal process steps needed to achieve true wood gasification.
And a willingness to bang with a heavy rubber hammer. Hand shake the whole hearth system. With my hands feel the heats system traveling. Tape up joints with adhesive, aluminum tape. Pre-hand load char beds. Select and dry wood chunks as their system builds demanded.
Good 'ol boy - Cheat-with-the-fuel, works.
For lower moisture content; true wood in-place char-abilty; ash percentage; and that ash’s resistance to melting.
And all of these I found that I could pre-trial in my home wood heating stoves. Made me a much better wood stove user. I now use 40% less wood. Less sooting… Much wider range of woods and wood portions able to burn clean with.

So no one way will be best for ALL, or even the majority.

Cut and weld. Try. Observe. Recut and reweld, try again, and again works too for your information learning too.
How Mike LaRosa became the very first American to woodgas drive modern electronic fuel injected vehicles.
How Wayne Keith evoled himself to become the longest and fastest driving daily woodgas user in the world.

Steve Unruh


I wanted to offer up a Third-Choice to home-power using woodgas.
Four-hour batch cycling/producing.

The other Choices pursued are continuous gas producing for as long as awake hours; and/or Grid feedback favorable. Gets really really complex.
The other Choice pursued is big batch making and then storing that “power” in a storable form for as-demand use needed. Has inevitable conversion state&storage energy losses.

Four hour batching evoled from my still working days with early morning firing up and heating up the house with the in-house woodstove. Leave. Be gone all day. Returning home from work doing this again, evening until bed time.

Wodgas making four hour batch systems can be more simply and easier make to work than any variation of the other two Choice approaches.
Ha! Four hour batch system stops making engine grade gas and the engine stops. Make easy air-in and gas out cuts offs. based on the engine stopping.
And this is not head noodling armchair speculation.
Been done. Used.
Why not you?


Steve would this be a way to covert diesel to wood gas ?
A hot-tube ignitor was an early device that fit onto the cylinder head of an internal-combustion engine, used to ignite the compressed fuel/air mixture by means of a flame heating part of the tube red-hot. A hot-tube ignitor consisted of a metal or porcelain tube, closed at one end and attached to the cylinder head at the other and an adjustable burner that could be moved to position its flame at any point along the length of the tube.
The compression stroke in the cylinder pushed some left over combustion products in the tube, followed by fresh (unburned) fuel/air mixture. When the compression was enough that the fuel reached the red-hot area of the tube, ignition occurred. On early designs, ignition timing was adjusted by adjusting the position of the red-hot spot on the tube—this was accomplished by moving the burner along the length of the tube. Most later styles used a fixed burner and varied tube lengths to change ignition timing.

Actually battery storage is much more efficient than taking oscillating power loads from a generator directly. This is unless the load is static and is matched to the static charger load.

I run the business off grid and I go through a third of the fuel if I charge verses I would direct power from the generator. Most of the time the generator is only loaded from the shop lights and this is wasting fuel away at this load. However my system is not capable of running the CNC machine or the 220 welder. So most of the time I dont have much of a choice. I do plan to change that as I will be working on battery storage systems for market. Big systems!! :fire: