Introduction post, professional mechanic and tuner

Just found this forum yesterday. So far I seem to like it. I don’t have hours and hours to search but appears not many folks have really tried optimizing compression ratios nor cylinder head flows for woodgas. So far it appears people like big cubic inch engines for the kinetic energy they provide and run them at 3000 rpm or less roughly emulating a diesel.

So I own n automotive repair and performance shop. I have tools and specialty automotive equipment at my disposal most people would dream about. I am starting 2 projects and will most likely become a semi daily poster here as it progresses .

As of right now with the insane state of the world I run a diesel truck that runs on waste engine oil and vegetable oil. That truck had head gasket failure after 500k miles so has been decommissioned while I do the rebuild and with parts shortages looks like will be down for 6 to 8 weeks… Buying fuel at 5.30 a gallon. Isn’t acceptable. I have only 2 diesel rigs and 15 or so gassers. I am a fairly serious "prepper " and over the years have pulled out of the system. A wise man once told me if you depend on anybody or any company for a daily need you are not free and independent but a slave to a product or service. So we grow and raise 99.9% of our food and slowly moving over to solar. Before I found this group I was building gasifiers to run a 9500watf
gen and now a bigger 25k. We are planting 5 acres of sugar beets for home ethanol production so I can always drive a wood hybrid and still run my chainsaws and such without big oil and insane fuel taxes. So that’s the backstory on me

Now the questions. What are your intake air temps with your setups ? I have a 5.3 LS style pickup that I am going to use syngas. These trucks have a plastic Intake so am curious what the average intake air temp is. I look forward to the LS because I have full control over timing tables with the laptop. And am thinking I am going to piggy back another pcm in order to use two diffent drive by wire throttle bodies in order to have independent control over gas and air and keep truck user friendly for the wife so there will be no manual air fuel ratio adjustments. The truck is already equiped with wide band o2 sensors that will accurately read from a 9:1 afr to 21: afr… Stock o2 sensors are only accurate to stoich of 14.7:1 … So with full control over pcm I will be able to make custom spark and even fuel maps when I hybrid it.

Second rig is a big block Chevy that’s never driven. This truck is a tbi 454 and will throw a burner on it fairly soon. Before the LS powered truck anyways. I have sitting in the shop a 14:1 565 cubic inch engine I will most likely put in after I perfect the process for non stationary engine and apply a stand alone ecm for fuel and syngas mixing. I am a little worried about it , with size of cam and airflow of the heads… It’s just over 1000hp on methanol… But maybe just maybe I’ll see what it does if I can keep the 454 clean of tar in intake.

Just thought I would say hello to the community .


Welcome Rob. In my personal opinion I think you have a decent setup to build a vehicular gasifier. I would say the most proven design for big engines that runs a wide variety of wood species is the Wayne Keith gasifier. Others will work just fine but I think Wayne’s power to weight ratio for his specs are really good. If you end up buying the book you’ll get 6 months of Premium access so you can take a look at all the WK builds in depth.

Take some photos of the gasifiers you’ve built in the past! We love pictures over here.

One of the big aspects of any gasifier is to make sure the gas is cooled down enough, down to the Dew Point, to drop moisture out of the gas before it’s filtered. You should be at ambient temps once it’s made it’s way to the engine.

A PCM system would be really neat to see. Now are you saying the second electronic throttle body would be for air mixture, or do you mean a second throttle entirely?

If you mean for an air mixer, that could make for a decent idea. A lot of guys make a vacuum controlled automixer to govern the amount of air that goes in. They have a manual air control for Gross Adjustment and the automixer dictates Fine Adjustment to maintain stoich.

With an injected engine you can run the gas through the original TB and hybrid gasoline with a PWM to the fuel pump to bring it down.

Almost any decent system operated correctly can prevent tar from going to the engine, it really comes down to Due Diligence.

Also forgot to mention, with any plastic intake or any intake for that matter, make sure you have a valve to vent gasses in case of an intake event/backfire. Some make their own and others use large flapper one way valves that will swing open when positive pressure comes from the intake.


Dont poor gobs of money into an engine. Yeah there are many of us on here that are engineers, engine builders, experienced auto techs etc. If you wood gas an LS motor your gasifier better make clean gas at all times. As soon as one valve gets a little sticky, you will smash the valve train!,… Been there and done it on a $10k plus GM performance engine that was sent to Italy. Yeah try getting parts for one over there lol took them 6 months to repair this engine.

We are all very aware of the benefits of high compression engines. Many ways to go about it, turbo is a no go, the wood gas will destroy them in a heart beat. Some have used super chargers with success. The other is to bump compression. If you have the time and money great. But for most its not really worth it just go bigger, as the saying goes there is no replacement for displacement.


To put on top of what Matt excellently put, it’s also a matter of expectation. Wood gas just doesn’t have the same BTUs as Gasoline, most fuels don’t. When I put a gasifier on my worn out 1986 Mazda B2000 I had the acceleration of a VW Beetle, but I could still climb hills(I live in North Carolina in the mountains) and I could still go country road speed limits. Wayne has exceeded 80mph with his Dodge Dakota with a 318 V8, lightweight pickup. He hauls a lot with his Dodge Ram V10, pulling hay trailers and cattle and I’m sure can go highway speeds pulling them or at least keep up speed on the Farm to Market roads.

The Flatlanders get to have all the fun with speed. I never went into Overdrive in my Mazda.

Edit: Also while I think the automixing can be valuable I also think you should have redundancy for manual override. Your first vehicle build I’d highly recommend you use manual controls to get a feel for what’s right, and use an AFR meter. In my Mazda I didn’t have any gauges to tell me what was going on, and I was still able to bring it to stoich by ear. Since you’re a mechanic you’ll be able to tell if it’s running too lean or rich just by ear but of course you can’t beat a gauge to tell you more accurately.


Yea I will be incorporating egt probes as well. So far haven’t found good analysis on what a stoich afr or lambda is …and I’m sure it actually varies from load of wood to load of wood. I have methanol powered and e85 powered performance cars and the best way to compensate for lower btu in those fuels is indeed compression. Of course will have manual controls as a back up and most likely right off the batt on the big block Chevy as I won’t be going for optimized but rather just functional to be able to drive without spending 300 week on fuel since my waste oil burner is down. One thing I am going to do for controlled environment testing is machining up an adjustable dome cylinder head for a flathead engine on a generator …I will then incorporate a stand alone ecm and fuel injection to learn what the engine likes for electronic controls and hybrid use… It’s not prime to test this way being a flathead and flow characteristics will be way off and power per cc or cubic inch will be way off as well but it will allow me to create a data base and really start figuring out the automated mixing apparatus.

As far as that. 565 BBC I will test in in stages… As it sits now and I suspect will have way to much cam and not enough down low and actually flow too much air. I mean any engine is just an air pump and the more you can get in and out the more power you make. However using a stable liquid fuel is way easier than an onboard reactor that fuel quality and btu content will vary greatly …

Initial thoughts is I will end up with that 565 with a close to stock cam with high compression and possibly a lower velocity and CFM head. Cylinder pressure is gonna be sky high. And as a backup I will have an onboard water meth system to be able to drive truck home on gasoline if a gasifer issue arises… Trying to run a high compression stock cam engine would detonate itself to death in short order without water injection to keep detonation under control.

It’s all gonna be a very fun project and wish I started it 20 years ago when I first read about gasification. It’s not that I can’t afford 5.00 fuel but it’s the principle of it… And honestly want to pull out of the system as much as possible and depend on nobody got anything so if stuff collapses I’m not scrambling to maintain quality of life.

My biggest fear is when locals start figuring out I don’t rely on big oil or energy companies… People will want conversions and if it’s true it takes an experienced conversion tech 300 hours I want no part in doing that for someone. That’s a lot of labor and way out of budget for most. Kinda like these people saying they can’t afford 150 fill ups so go buy a 60k electric car at 900 a month and then sit idle when the power goes out for a week at a time in my area …lol


300 hours is a rough estimate if you take your time on a first build or a really in depth build, for a charcoal unit on a smaller engine I had it ready in a weekend once I had parts at my house.

That being said I wouldn’t go about selling vehicle units, since you’re not paying road tax for the wood and all that. Guys that sell gasifiers they’re intended for generators and other stationary engines

Compression definitely gets you closer to stock power. Also avoid a Lopey cam. Steve Unruh has suggested an RV designed cam profile.

Also you can run the wood gas straight through the carburetor, @Norman89 does it on his 350sbc powered Toyota. Gets it dirty though but it still brings in the gasoline.

A good habit is to start and stop on gasoline so it can clean the intake valves of any accidental tar and other mess.

Also check out @JO_Olsson Volvo build he recently did and take a look at how he filters the gas, he doesn’t get a lot of soot on his throttle body. You would just need to scale it up for your Big Block.

If you have any questions don’t ever be afraid to ask on a post or in private message. If you do buy the book have a little patience, Chris Saenz runs the site but he has a day job and a family to look after.


Thanks for the suggestions. Yes definatley don’t want anything to do with retrofitting cars even if I get pcm control… The states will go after the road tax like you say and fall back on me. I would be open to getting close prepper friends or family set up on stationary power but not even them for motorvehicle.


Welcome to DOW. If you haven’t seen it yet, I think you will enjoy this DOW thread:


You will need to set up your instrumentation for woodgas. If you can find the scale for NG that will be very close. I use AEM O2 Sensor kits using the Botsch wide band sensors. I believe you can set up the gages for different fuels. I use these kits for the lambda input for electronic fuel controls but I dont mess with changing the scale. Woodgas likes to run a little higher up on the gasoline scale around 15.5 ppm. There is code here on the site to build an electronic mixer control, I am the creator of it. This controller is now 8 years developed and hundreds of them have been built.


Wecome to the DOW RobW.
You experience and goals should make you fit in well here.

Couple of points about woodgas. The three primary fuel gasses are SIMPLE molecules. It does not take nearly as much oxygen molecules in-cylinder to have them fully combusted creating the needed pressure pushing.
And that is good.
Because they are space taking up physically bulky to also have to stuff into a cylinder.
50-50; 1 to 1 +/- maybe 10%.

2nd point to get yourself out of RPM for power watch a lot of WWII piston aircraft engine videos. Puts you mind-set into piston power makers in the 2000 +/- RPM range.
But beware of the seduction of their compound boosting and then even added exhaust turbo charging.
Consensus is now you’d have to equal pressure boost the whole gasifier hearth, cooler and filtering train to get the woodgas forced into the engine to match the air boosting capability.
And that’d be super Gov’Mint cost-plus expensive, and dangerous.

Steve Unruh


Welcome Rob. You have definitely fallen in with the right crowd. You will find common ground with Bruce Jackson on your bio-fuel endeavors and others of us are always interested in any form of self made alternate fuels of any kind. I was not always in the category but the more I learn the more I find the Kiss principle to be the wisest path. I spent a fair amount of time and money in the past enamored of Chevy performance engines. Too old to try and learn to adapt to electronic anything but having the ability for have a ECM monitor timing is a definite plus. If you have the equipment and funds to build a high compression engine and can still hybrid it then more power to you. Otherwise most here have found that displacement will overcome the shortcomings of Woodgas fuel without a lot of engine modification. You meth injection system is very interesting to me and something I have been considering for some time. Details would be appreciated. Being a “fairly serious prepper” you are aware that the supply chain is broken and is not likely to recover. Outside of a geared distributor with a supply of extra HEI modules I am committed to old school engineering.


Hi Rob,
I have long suspected that a 14.2:1 CR engine should maximize power on woodgas. We have a Ukrainian guy on here, Joni, who did 12.7 with positive results. Link
We also have a Slovenian guy, Tone, who wood gassed a diesel farm tractor. Says he gets about the same power as with diesel. Link
My ideal wg engine would be a diesel with a thicker head gasket to reduce the CR to 14.2 and a spark ignition system. Of course I’d match the ports while I was at it.
I’m in process of making a water/meth breather. Just a simple way to put extra humidity in the intake air and increase economy. Your thoughts on this?


Hi rindert.

I have only done gassification on a small engine as a science project decades ago so the experienced operators would have better idea with large cubic inch stuff . I know :100: running a bubbler with water meth will absolutely increase efficiency with liquid fuel engines but my concern with wood gas is the water especially turning the soft soot in the intake to a more abrasive sticky tar with a higher durometer. In fact I have been really pondering this exact issue long term. You see in heavy class 8 trucks I saw engine reliability go down by a factor of 50 to 60 percent . In frame rebuilds used to be 1 million to 2 million miles. Well in epa2007 trucks that went down to 500k or less. The egr was introducing large amount of carbon into cylinders via egr… It would wipe the crosshatch and rings right out of them. Now the carbon was much more course and sticky than soot from my old gasifiers. My hypothesis is the carbon created from combustion of diesel is much different in durometer and particulate size. Carbon in the right form can be a lubricant but also can be one of the hardest elements or more specifically make elements harder. … But the diesels also use a egr cooler that is very rapid and no place for condensation to drop out like gasifiers have.

So I’d be curious on results of a test like you out forth bit would definatley try on something like a back up rig or stationary genset.

Another subject I ponder is the mpfi vs tbi thing… To me a tbi could be used to clean intake runners on every use… A simple use of liquid fuel on shutdown to wash out carbon. A mpfi won’t do that because of location of injector. My hypothesis is to use either home made ethanol or methanol for the liquid fuel as it evaporates fast without leaving trace substances in tract and is a more powerful solvent to the soot. And the fact it needs 30% more by volume means the soot dilution is greater. My fear is the caking when ethanol is introduced and possibly washing too much soot at once making a mechanical hydrolock if you will.

My current project is my 454tbi so will be testing this. First thing is to get rid of egr crossover cast iron manifold with an air gap aluminum manifold that I can cut apart and orings intake part for rapid intake removal and inspection without coolant loss and valley exposure. Got lots of testing to do and will be a fun journey .

Also looking at a 20kw stationary genset that uses a log straight 6 ford tonight. Hopefully can strike a deal and will be installing a microsquirt controlled tbi on it I have laying around.


Also running woodgas through a water scrubber will turn into a mess very fast. I tried using a water scrubber years ago to clean gas but found the amount of water was quite high. Did work well until water was oversaturated with soot. It again this was a short term project for me then and somebody here may have experience more long term and have a solution. Off to the search bar I will go after work. :joy:


The soot from a raw wood system like what most have found isn’t exactly the same as the soot found in poorly filtered charcoal gas. It doesn’t contain ash.

Wayne actually burns the soot off of the throttle body with the engine running on gasoline, he has port injection otherwise it wouldn’t be safe.

I think it would be worth experimenting adding a water/methanol bubbler connected to the fresh air intake but I don’t think it’ll keep everything clean. Would be better to invest time in a bag filter or series of progressive filters.


Hi Cody, i think gengas Werner or Lars Toresson uses a bubbler with ethanol (E85) on their truck, says it helps to keep the intake clean, think i saw it at: omstallningsresan on Youtube.


I think a higher concentration of alcohol would work, adding water wouldn’t do much other than preventing it from evaporating via engine heat.

I live in a hot place when it’s summer time, the cab of my truck exceeds 100°F when left in a parking lot so I can only imagine how hot the engine compartment would get. Methanol evaporates starting at 140°F and ethanol at 175~°F


Wheeew, thanks for that info. Just convinces me even more to make / use use primo filters. A kid at a Case-IH dealership parts counter once told me modern filters, a Hall ignition, and synthetic oil can make a Farmall M tractor go 4 times as long between overhauls, so actually no surprise.
I never heard of the mechanical-hydro lock, as you call it, thing happening. People report a ‘smoke event’. LOL I guess that’s when a chunk of stuff comes loose and goes through the engine.
I guess I will go forward with my bubbler. Thanks again.


I’ve had carbon knock the bearings out of an egr diesel and actually cake on a layer of rock hard carbon that breaks piston… Not saying it happens is wood gas as I haven’t applied to vehicle yet and soot is different… It’s just a thought I had to watch out for. I push boundaries of common practice and at times bites me in the ass…lol


Rob I ran my charcoal gas straight through my Weber 32/36 carb and the intake is as clean as it was before adding the gasifier, so I agree it would definitely keep the intake runners and valves clean. I ran a seafoam spray session every once in a while to clean the throttle plate of the carb though so maybe that skewed results.