Oh i wish i could always put my finger on why its running nothing like it did last week or this or that , but i guess that’s sods mechanical law .
But to be honest Don i really am no expert when it comes to raw wood gasifiers or even downdraft for that matter , but i am learning as i guess we all do over time and being able to share thoughts and idea’s and congratulate the achievement’s and help to pin point the fails as we travel along this fantastic way of ours .
Dave
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Atmospheric conditions change Dave. The people who tune dragsters have often compensate between runs for changes in air density and humidity. What happened to Robb?
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Once yet again I have to thank you all for your input and the learning experience I am receiving here.
Yet more misconceptions of mine exposed.
I had always heard that propane and woodgas were very similar, so my flare design followed a simple propane torch design that I use at my farm to burn weeds. And also the piping that works for my propane generator - I assumed would work for woodgas as well.
Frankly the only reason I have not given up on this project yet is your patience with me and you all always give me something new to think of, where I might have gone wrong.
So now the question it raises for me is the piping to a small engine carburetor - if we are going with a large pipe - say 1 1/2 - but then the throat of the carburetor of a small engine usually being only about 1/2’- maybe 3/4’ opening - so then is there just a brief reduction as it introduces to the carb - are there any small engine guys out there that maybe have a picture of this construction?
What it sounds like if I am hearing - if I am hearing right is to keep the volume of woodgas as large as possible up until the very last moment before it is sucked in the carb. Also, Jan had mentioned a 50/50 gas mix and I had accounted for that or at least tried to - in my current configuration, right before the carburetor, I have a “T” with a ball valve plumbed in so I can introduce some air into the intake, but the YouTubers I had seen start their small engines I saw some start with pure woodgas - kind of like like starting on “choke” and then gradually introducing air through the ball valve as the engine warms - that’s why I thought it was ok to try to start it on pure woodgas, but as I keep learning there is a lot of bad info out there on YouTube.
One final question I thought of - regarding the blower - although it has a good velocity it may be restricting the woodgas airflow since input and output ports are 3/4” so if my output needs to be 1 1/2” I am already starting out with half that size due to the blower. I wonder if I would be better moving that blower to my input leading to the oxygen nozzles and make the blower a “pusher” instead of a “puller” - pushing air through the system instead of drawing it through. Can I still achieve a down draft this way? And does this seem like a good direction to move in? If not I will still have a lot of rework to consider since all my output piping begins at 3/4”. Not sure how I started in that direction, again probably something I saw on Youtube in the early stages before I discovered DOW
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Yeah and its funny you should mention that Tom , because I actually do live in the clouds and most days we have low lying cloud due to the fact we live half way up a mountain here so everything does get rather damp including the charcoal in the gasifier , i have been giving that a lot of thought since testing downdraft units , i think i may be making too much hydrogen ?? if i add a constant water drip of more than 1 drip my revs start to increase and 10 seconds later my generator motor starts to coff & pop and slow and then speed up and then stop it will start up again no problem and run till its putting out its full power and if i still have the drip going do the same again , if i stop the drip after a few mins it will settle down and run outputting full power at the lower rev range .
I think it may be time to take the head off and look at the valves as they may be needed a lapping , i also have a thinner head gasket for the clone GX390 engine my generator uses , so i might take a little off the head and help increase the compression slightly .
Dave
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Hi Derrick , don’t over complicate things to start with keep things as simple as and once you get going and have a taste for things to come then start experimenting every which way .
The size of your carb intake is set there is not much can be done with that and so as you said i think it will make things a lot easier if you can get as much un restricted gas to your carb asap , so larger clean runs are best .
The air mix valve is a strange one to master as nearly every engine i have used has a totally diff setting some slightly open others nearly two 3rds its a suck it and see and that’s why i said get someone to help rotate the engine while you master the air adjustment .
On the pipe size once again bigger is better BUT you most certainly can run a lawn mower and flare with a 3/4 pipe and fittings no problem at all as it will be a stationary unit anyway and will not be demanding full power , i use a air mattress pump to pull on my charcoal system to start , your raw wood system may need something with more suction to get the unit up to heat faster , why not try blowing into your air inlet with the fan and see how that goes , i have done that myself in the past once or twice .
My carb intake is roughly 3/4 and i have a 1 inch boss bolted onto it so i can use a 1 inch flexible pipe from my air mix valve
Dave
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Oh - one more quick output question - if I reconfigure my output and go all 1 1/2” and I want to try a flare - does it reduce any at the flare - or just strait up 1 1/2 all the way?
Do you mean reduce the pipe for the flare ? no just make sure it can mix with enough air and it should burn
I would put a 3 inch can over the 1 and a half in pipe and drill holes around the base of the can .
Dave
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Thanks Dave, yes that’s what I am running too is a 12v air mattress pump which fits nicely into a 3/4” outlet. So maybe to minimize any changes, I will try moving the pump to the input to see haw that does and just make sure I have 3/4’ all the way to the generator and see if that makes a difference.
Fingers crossed you will get there soon
Good luck
Dave
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Hi DerrickD,
On your produced gasses mix to air for the engine that one-to-one is just a guideline. Very common it can be as much as 20% fuel gas richer or lean with 20% more air. Lots of Depends-Depends to this.
The youtubers you see starting on a full woodgas are actually smart. You want to have the whole supply side piping purged of all air and only have the woodgas in it. Do not valve that gas. Let it suck all in that it can. Then cranking over on that YOU then with the added air valve are bleeding in the air. mixing based on the true systems needs.
To begin with and even settle long term with if you’re getting the shaft power you need just seal up the small engines air cleaner box if it is metal. If plastic; make up tout own Box out od a section of square of rectangular steel tube. Allow no other feeds into that mixer box like the crankcase vent breather. Then add to that box a small hand valve for your air blending control.
Each have their own favorite valve types. Dave mentioned 1/4 turn ball valves. I like true gate valves. Other have adapted over a small actually plate throttle body. All will be super sensitive on the best operating openings.
Realize that once running the engine will be pulling fuel gas in through all of your systems internal resistances. Filters and piping drag resistances.To help match this on the air valve side it helps to add a motorcycle or hotrod type cone filter. Give you engine cleaned air and some suction drag to match the gas dragging.
Now this next gets into advanced stuff for maximum engine power. Anyone using a gasoline carburetor as their fuel-gas/air speed control has a built-in power limiter. The narrow waisted carburetor venturi (needed to suck up and spray mix the heavy liquid gasoline) will be a flow restriction point then. True single fuel propane and methane single purpose “mixers” have very minimal venturis and will give more power converted to woodgas. The more open throttle body’s on a true port fuel injection system will allow more flows for more power on woodgas.
Some will Dremel-tool hog out their small engine carburetors. Tricky, tricky. And then IT CAN only use woodgas.
Other like me have played around with purpose building internally open dedicated small engine woodgas/air mixers. All experiences with multiple cylinder engines with an overlapping steady intake vacuum go’s out the window with single cylinder engine beasts!!
I expect few to believe me but efforts on this are much better spent on other areas of the whole wood-to-motor grade fuelgas system.
Just figure on using larger single cylinder engines to get your needed shaft power. And the larger engine system are almost always electric starting to boot.
Regards
Steve unruh
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Just to kinda reconfirm what others have said, each system wants what it wants, and its your job to learn how to operate it. Trust me the struggle is real trying to figure it out on your own with no experience but the words of some feller on the interwebs. Yes there is a lot of bad and misleading information on youtube, a lot of look at me I want views bs’. It took me a solid 8 hours of fiddling to first get my truck to fire up on woodgas. Frustration was unbeleiveable! Still to this day it is not a perfected thing to start on straight woodgas with no dino juice bump start and warm up then switch over. This is best achieved with my truck by running pushing and pulling blowers for proper warm up, noting as wayne has said many times over a light haze gas, not thick smoky tar making goop. Once warmed up, then pulling blowers off, woodgas valves open at the engine, air valves open and let woodgas be pushed all the way to the motor for several seconds. This will gently haze out from under the hood. This insures fuel is at the ready right at the carb before any cranking happens. Here is a video example
But at todays fuel prices ( payed 5.17/gallon last night, 97$ for a half tank in my dodge 
) I try every chance I get to start up on straight woodgas. Maybe 6 times out of 10 I can achieve it. And depending on how well the system is breathing will change my air mix settings, often as im driving minor adjustments are needed when running on softwood pine and doug fir, not so much on hardwood maple and cherry. I have 2 2" gas supply lines and 2 2" air supply lines each valved with a fully sealing throttle body. On my particular truck one air valve is always closed off completly and the other air valve is only open about 1/3rd, both gas lines wide open. 70/30 MIX?? But thats what my truck wants. I could delete the second air valve entirely, but that extra air is needed for those rare times im running on gasoline. If running on gasoline there simply is not enough air to supply the venturi correctly and it over pulls fuel and runs pig rich and starts fowling plugs. This should be a very clear indication that im sure other woodgas operators have duely noted how far apart woodgas runs from gasoline. It is not like running a engine on any other type of fuel we know of, its own beast. A beast that must be harnessed and taught to behave. Unchecked and unbalanced is tar production, system clogging, overheating irritation of the bang your head on a wall variety. Keep your head up, your nearly there. As Wayne has said before, wish I was there, im sure we could have it up and running in no time. Once you get it running and the other 75% of the learning starts flowing, you will look back on these early frustrations and know exactly what needed done to make it function. This to shall pass
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Robb is balls to the wall on his build last a talked to him a week ago
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Very well said Marcus, it getting through the learning curve and knowing the other 75% of your oun gasifier build. Same WK design basic but they are not the same in operations. Imbert, other gasifiers different too.
Great start up on no gas . Take that oil companies for over priced fuels. I bet it makes you feel really good you can give them the wooden finger and drive away.
Bob
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Let me ask this - I know we have talked about the flare not being very important, but if I can achieve a sustainable flare this should indicate that the gas would be of a good enough quality that I should be able to run an engine on it- right? The reason I ask is because here is what I am thinking:
In a “divide and conquer” strategy - I am thinking maybe I will rework my flare and focus solely on being able to produce a quality gas at the flare before I even try to run an engine on it. I figure this way, instead of chasing multiple rabbits down their various trails, I can isolate one thing at a time, and if I can get it right at the flare then it should at that point be just a matter of getting the plumbing right to the engine.
What does everyone think of this plan of action?
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The most important thing you can learn from a flare is how quickly it ignites. Also how dirty it looks before lighting. If it’s super smoky thick then it has unconverted tars. Best look is a slight haze.
If you can ignite it with a sparker for a welding torch then it’ll ignite in an engine.
I had issues with sustaining flares, and it’s because I never bothered with making a good flaring torch.
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Look at your air mattress pump and make sure that there is no way for it to suck in air. The bilge blowers many of us use have a small opening in the pvc that the wire go through. My first build I didn’t know that amount of air was a gas killer until I pumped some silicone in the hole. Most generators have some kind of cannister for an air filter. Easiest way to get gas to your carb is to pull the cover off. drill a hole in the cover large enough for a threaded pvc male fitting to be screwed into it and then tape up all the openinga where the filter recieves an air supply. Easier than trying to make a flange to bolt to the carb.
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Depending on the engine you can also get a Pod Filter Adapter.
If it’s a Honda or Honda Clone you can get these for reasonable prices from go kart stores on eBay.
Then you can use a rubber coupler to the carb directly.
This replaces the air box, and as a bonus you have an air filter you can use on the fresh air side.
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If your ultimate goal is to fuel engines for power using woodgas then what has time and time again proven fastest, best, is to just start with any produced gas fueling engines. They will run quite well on just smoke if it is HC’s rich smoke and not just mostly water vapor.
But two things:
Use easy to recover engines. like an old single cylinder flathead/side-valve/valves-in-block types.
Tar up and stick open a valve and it is just pull the head and spray down cleaner pushing down on the valve; and engine rotating to get the cam to shove it back up. Up and down. Up and down. Until freed up. Then do something gasfier different, learning. Dryer wood. Hotter gasifier. Better established char beds.
Second thing is to for now set aside all you have made and make up a Gillmore charcoal can gasifier and run an engine with it. With good wood charcoal it cannot make tar or excessive moisture. Train yourself on air mixture settings and basic operation techniques.
Then go back to a raw wood system.
I still keep a once new 400 hours worn flathead B&S to loan out as a test mule. Just this Spring finally shaft bent a 800 hour plus Honda OHC engine been swapped onto it’s 3rd deck that can now be a woodgas test mule too. My friend Marcus says these are real valves benders if valve ever gets stuck down. Most modern slant cylinder overhead valve types will just bend a push rod. Done that. Fixed that. Learn until the bore and compression is gone. Then move on having learned. Ling up another test mule engine. Sooner versus later a fellow does learn.
The way to quickest learn to ride a bicycle is to fall off a lot and bleed some. Until finally no longer falling down.
Same with swimming. Have a life-line couch on that one.
Airplane flying? Hang gliding? Untra-lite/para sailing? Nope. Nope. Nope. Crashing will be too serious.
I chicken. Never done any of these. (Just flying cars, a time or two - yep, those landings - they did hurt - a lot. I still limp. Have bad dreams sometimes.)
S.U.
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Derrick,
I do find it easier to test gas quality by trying to light a flare than pulling a rope to start an engine.
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nothing like a little spinal compression and whiplash to make your brain think “man I’m stupid! Not doing that again…” then in deep sleeping dreaming of high dollar king coilovers for next time.
As Steve so well articulated, your on your training wheels. It aint easy trying to start learning to ride a bike with no helmet kneepads elbow pads and a pillow landing! And trust me we are not trying to give you a hard time, there is borderline an artform balancing everything needed to run an engine on wood. Save the back and shoulder ache when you get to an engine running, go for the drill start. Prime example here is me trying to run a small engine for the first time on wood off the gasifier in my truck. yank, yank, yank, yank,…
And at this time I had already been driving the truck on wood for several months! Don’t mean I knew how to run a small engine
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