Hi Jacob, I have been using a 7 1/2" on my 92 Dodge Dakota with a 1 7/8" opening at the throttle body one opening for wood gas and one opening for air mixing on the auto mixer. I am sure I could go with a larger choke plate like 7 3/4" if I went back to a manual mixer control 2 2" gas piping and air mixing pipes, like Wayne had on it when it was first built or like what you have with a 3" gas pipe and 2" air pipe for mixing.
Keep your SWEM going.
Bob
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Bob I have been meaning to ask you what do you think about the auto mixer is it worth building and maintaining or are the manual controls just as good.
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Hello Jakob .
I think I am using a 7 1/2 inch choke plate on the dakota.
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Jan, no wonder you have power issues! I run a 11cm restriction on my 1.6l Cevy! You need to go biger.
Allso the firetube is too small for sure. Keep in mind the actual active area starts with the nozzle circle. Doesent matter if your firetube is a 100 inches if the nozzle tip cyrcle is 5 inches the gasifier is a 5 inch gasifier.
Thats allso probably aiding to your bridgeing problem. It seems making the gasifier biger is inevitable.
Dont worry about idle. If all else fails you can rise the idle rpm to say 2000 then choke the secondairy air down. You will get a stedy 1000 or so rpm with good gas draw. Not the most economicsl way but you will have a powerfull gadifier that doesent make tar at idle.
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Thanks Kristijan.
I had no larger fire pipe than 9 ", I can make the restriction bigger and the nozzles I can unscrew, becomes 16mm x5, but I also think that a larger fire pipe would make me avoid bridges.
I think that’s why @JO_Olsson doesn’t have problems with bridges, because his pipes are bigger on the top.
Do you drive on wood or coal in your cheva
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The Mazda firetube is 10" and Rabbit’s was only 8", I used the same size fuel and I can recall bridging only a few times when chunks glued to the funnel after sitting for a while.
I mentioned before and I still think your funnel is too steep. Too much sideway force keep a bridge intact. A shallow funnel will leave a few chunks left on the sides that won’t fall in, but that doesn’t matter.
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It will be the next attempt, remove the cone and insert a little larger
restriction, the question is if I should remove the nozzles and only run with 16 mm nut?
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Some wise people here say try one thing at a time.
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Who said that?
Hi Jacob, this is a very, very good question to ask for everyone here on DOW who want to build a auto mixer for there vehicle.
First of all Chris built the original mixer for this Dakota truck. I have now completely rebuilt it and fine tune it so it is working pretty much trouble free. After many, many unrecorded hours, like 100’s of hours working on it, I can now say it is at the moment, working fine. After making this statement something might go wrong with now. Lol.
The main problem with it is the 1 7/8" Ford 150 throttle body openings are just to small for the 318 engine that is fitted in front of the Dodge throttle body. I only have 1 Woodgas opening 1 7/8" to feed my engine and the other opening is for air.
I really need a larger gas feed opening.
Wayne’s Idea of two 2" Woodgas piping feeding into the engine with both valves wide open is the way to go or one 3" pipe like you have. It take a long time for me the get from 65 mph to 70 mph with out adding a little gas. Up to 60 mph on the flat ground it is fine.
Wayne’s Dakota will beat me every time if we ever race, Simply has more wood gas to use on the top end when driving for pulling a loaded trailer, I do not unless I blend in some dino fuel.
So if you want to spend time working on the auto mixer and not driving your truck then yes I would build one. But make it at least a 2 1/2" openings for the throttle body.
I was going to convert the truck back to it original way for mixing gas like it was on Wayne’s orginal 92 Dodge Dakota from the book before Chris built the auto mixer, and make a comparison of the two. But after riding in Wayne’s Dakota I do not have to do that now.
I’m just trying to keep it working now and I think it is the only truck in USA with a auto mixer on it.
If I did converted it back I might just leave it that way, because I sure I would have more power at top end speeds and I that would be something I would like.
One big plus is the way it is right now, I can not over pull my gasifier as long as the hopper has wood in it. I have tried, it gets to around 1670 to 1700* f at the grate in the hot summer months and stays there until I take my foot off the gas pedal and slow down.
When I rode with Wayne in his Dakota at Argos I did not notice him having to adjust his air mixer hardly at all. From stops to starts and just driving down the road. But he has fine tuned his driving skills like you have been doing over the passed year of daily driving. You get to know how your truck and how it drives and drive it according. You have two trucks now and they do not run the same way because the gasifiers are not built the same exact way.
The only advantage I see in my auto mixer vs. manually mixing the air/gas ratio is this, anyone can drive my truck even if they have never driven a gasifier truck before. I have proof of that at the last Argos meet up. That was my big goal with my truck in having a auto mixer. Putting in all the countless hours working on it finally paid off. I know, I know just call me weird, that’s okay, I’ll take it as a compliment, that’s the way God made me and I’m okay with that.
How ever, my next build will not have a auto mixer on it. It is not worth all the extra work messing with it. I just want to go down the road with a big SWEM on my face and just manually do the adjustment myself. I hope this helps everyone that is thinking about building a auto mixer.
Bob
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Hello Mr Bob .
Here is the 92 dakota several years back
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Thanks Bob
The only reason I would want an auto mixer is because of getting other people to drive on wood. If an auto mixer always operates like yours did at Argos then i should be able to get others to drive it. The problem is i would never trust them to travel far because they don’t know how to work on it.
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Thanks for the status update on the automixer Bob. I feel much the same way about it. If it were just for me, I’d never bother with it. On the throttle sizing, keep in mind the Dakota throttle body has roughly the same size throttle opening as the Ford one, as they are about the same size engine (302 vs 318). Wayne also passes all gasses through the stock throttle body. Part of the problem on your truck is trying to coordinate two throttle bodies in series. There is no way around that on that engine. It’s a big part of the troubles you’ve had.
The automixer was intended for the “woodgasser’s wife” if you like. She may be willing to learn the controls, but she is concerned that the engine will stall in traffic, or not restart at a store. She’s willing to put up with watching temperatures and adding fuel, and she makes YOU do the cleanouts.
Perhaps the better setup for her would be to improve the hybrid system, so that the vehicle could more easily be run on gasoline without flooding. My first truck had two throttles, no matter what happened on woodgas the gasoline safety net was “on tap”, just touch the other pedal. You did have to pull the timing back before going 100% gasoline again.
On the next truck I do, I will try to incorporate both concepts (automixer and dual throttles), and we’ll see how teachable the system is. But I’m with Bob otherwise, it’s really not worth it just for the primary woodgas driver.
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Jakob, as Bob hinted, you always live in a kind of fear driveing a automixer. It works but it only works if everything is just as it shuld be. No leaks, no loose charbed… a manual adjustment will compensate for that.
Allso, there come times when you dont want a 1:1 mix. Like warming up the gasifier or a long idle. Not good with a automixer.
I think the only practical safe way we can make automixing work is to go the electronic way via the o2 sensor. Hard to mess up that after its working propperly. Warm up on petrol for a few seconds, swich to gas and thats it. But this seems like a far future, l am yet to see someone come up with a simple cheap electronic design. I wuld get to it but my mind lacks some horsepower for that 
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That is high fruit, not hanging low if you are not into it. Didn’t someone make a design? Ben’s gasifier?
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Yes. BenP even publicized his system in a buy-it book. Exhaust O2 feedback system. Fairly simple. For a constant speed electrical generator. Honestly probably not able to multi-vehicle conditions driving. As KristijanL said well - you can drive away manual on a warming up still unestablished system, manually. Not something I’ve seen in any electronic control system yet.
APL/GEK did this much too using engine exhaust feedback. A proprietary them made control board with their own data-logic.
And some have made up Raspberry and Ardino based controller systems.
One German fellow YouTube presented a big wood chips fed American Van system that had enough brand recognizable industrial electronics to run a complete manufacturing plant. Ha! System was too non-use clean. His big flat sided gasifier system constructs showed lack of stiffening bracing. to resist the in/out pressure tin-canning. And No black tar streaks so unlikely he ever got it to run reliably.
Same. Same problems as a purely vacuum/flow/mechanical system.
Always have some one-point failures built in: in the devices; in the Logic train.
Who will ever understand it but the actual developer? Goes NFG, then what? Remove/bypass, discard.; and back to a manual system anyways.
So why even those of us with the experiences and knowledges in industrial systems controls will just go with operator training in manual use for DYI gasifiers.
You WILL be there anyways whether you “back-to-the future” or not initially.
True, in-LIFE use is not a geeky maybe-works, I-do-Better-next-time head-game.
Those resources you squandered with your imagineering better-ways, are often one-time-only use. Used up in trials and then you will without.
S.U.
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I did a tutorial right here on this site. That system would be built just the same way and code now is very fast and responsive. It should work very well on a vehicle. The latest code is up on that thread.
Me ill never have a system with out it at least not on something I had to rely on everyday. Systems with this set up and automation are nearly as reliable as running gasoline. If sure the larger WK units are more stable than our small scale systems. But it is very nice to never have to deal with manual mixing. Once you get running this mixer is very reliable.
Todd Harpster aided me in the later part of code development. This code now is very fast and responsive.
Your biggest challenge is not this controller, its the intimidation factor of it. Get the parts and build it. If you have trouble ask me Ill help you. $200.00 worth in parts, is not expensive for what this thing can do. Its actually quite an achievement at this cost. This thing is worth every penny and its now over 6 years developed.
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Bill here has replicated this system from this site.
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Matt, how did l miss this???
You are right, this poor mind of mine is a bit intimidated by the programing part but l will get to it some day.
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The code is already written. All you have to do is load it. Its very easy to do 
If you have ever transferred photos from your phone or camera to your computer, you can transfer this code to an Arduino.
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