Jan, how often are you checking the charcoal on top of the fire down to the lower part? Just wondering because if I do this it takes 50 miles / 80.47 kilometers for the charbed to reastabish and settle back into nomal operations on my truck. I always will check my cleanout below the grate if I think it is to tight after poking the rod down into the charbed and through the grate opening if that doesn’t work.
One clue is if I notice a high vaccum after the grate and nomal hopper vaccum. Maybe 4 to 1 or 5 to1 when driving down the road on a level road slightly excelerating in speed. If it does not go back to normal then my grate is to tight with fine char and ashes. I try not to empty my firetube, I just poke it more with more holes through the grate with my poke rod or use a T handle grate shaker? Also placing a bigger piece of wood in the center of the hopper when filling it up will help loosen a to tight charbed above the grate area.
Normally I don’t check it, the reason I took the wood and charcoal out of the hopper on this car was because I wasn’t getting any water from the hopper, I suspected that the hole for the drainage was too high up or was clogged.
Now this works but the car is still strange, is very sensitive to air, Johan Hedengren has helped me find a fault, he usually calls when I post a video and tries to help.
I can’t get my gengas unit to work, I have about 7mbar through the unit and 400-500 degrees c out of the unit.
Can drive at a maximum of 70-80kmh, when I get to a hill it is very tired.
I moved the throttle up from 14cm to 11cm from the nozzles, it got better, the throttle is 12cm, (I have 13cm on the other one)
Feels like there is a lot of resistance in the gas, wondering if I have a throttle on the line to the engine or if 12cm is too little, I think it feels like the gas is bad.
Or do I have a heat leak when the temperature is 500 degrees?
Hi Jan, 500° sounds much, maybe a hot leak.
Could also be incomplete reduction, then gas carries away heat from the process.
How much have you been driving with your new gasifier?
A well dimensioned imbert could take a long time to “build” it’s perfect reduction charbed. (Burning and replacing the charcoal we initially fill it with).
I’m guessing 70-80km, I think it’s so strange, it ran very well the second time I was out, had a lot of charcoal in it then, but now it’s completely powerless, perhaps indicating a heat leak.
I usually have about 300 degrees after the cyclone on the other car, should have over 400 degrees before the cyclone on this one.
If there’s a small leak right after the outlet on the unit, does it make a big difference to the quality of the gas?
Could be, could also be the reduction charbed burned out, has happened to me, newly filled imbert gasifiers are sensitive, could be enough with a shorter drive on flat road to get a shortage of reduction charcoal, then when shutting down/parking, som left oxygen and heat will consume some more charcoal, next light-up will also consume some reduction charcoal=it runs crappy, light-up smoke will look different, outgoing gas will be hotter and hotter.
When on first drives, establishing a good charbed i try to use a good mix of wood, birch mostly, and pine/spruce. Running both hard and slow, mostly bumpy gravel road.
Here the dimensioning balance comes in also: a perfect imbert produces only as much excess charcoal as is consumed in reduction. This is impossible to calculate, as road bumps, quality of wood, and a lot of other parameters will throw it of.
(Tone has come around this in a very innovative way)
You may try: feed it smaller wood, drive around atleast two hours, mostly bumpy road, see if charbed settles, try mixing in more harder wood.
After driving about a week, then start make conclusions. Poke more often.
Thanks Göran, I’m not used to this, I can do almost anything with my other one and it works.
Jan, you can build two gasifiers almost the same. But they will have some differences in how they work and when breaking in the reduction zone. I modified the same WK gasifier and it changed it alot on how it ran. Good advise from Goran, he has run alot of imberts.
Went out to get some firewood for the car yesterday afternoon.
Wondering if the problem is the hopper, I can get very little water out of it, probably because it’s so small and hidden behind the cab and behind the radiators.
I know with the old one when the outlet gets clogged it runs poorly?
Goran, thank you for your kind words, well, I feel obliged to justify them.
Jan, as I “thought out loud” last time, I will now continue with this,… if I imagine your 4.2 l engine sucking gas from your gasifier, it seems to me that the diameter of the hot zone is too small, especially if you use spruce or pine wood, which forms little brittle charcoal. The suction of a large engine literally pulls all the gases down from the air nozzles, so little energy radiates upwards for the pyrolysis to proceed adequately quickly, the charcoal is formed too slowly. I already wrote in the numbers, where I stated that the temperature and energy of the gas are just right for efficient preheating of fresh air, for drying the wood and for the pyrolysis to proceed, but it is not enough. The exhaust gases from the engine do this well, a lot of tar gases and charcoal are produced above, and all of this comes into the hot zone with high temperature. You also mention that you get a little condensation from the funnel, which confirms my theory, the moist tar gases do not circulate in the tank, but are largely pulled down by the strong engine thrust.
Thanks Tone, you’re probably right that it doesn’t make charcoal fast enough.
What I’m surprised about is that the old one, which looks pretty similar, works so well, but I know that before I raised the hopper, I had problems with hanging and couldn’t get much water out at all.
Sorry Jan, no easy-to-make, the mixer could be made in a lot of different ways, from a simple T-type, made from grey plastic (Jula avloppsrör) to special advanced types.
Take a piece of the pipe you intend to use, draw it’s inner circle on a piece of thin stainless, then draw another circle slightly offset (2-3mm) on the other, cut it out with “plåtsax” a little bigger, then grind it until it fits nicely inside the pipe, and you got a air-valve fly/flap, slightly oval, so it cant spin inside pipe.
Drill through pipe for a piece of round shaft, put shaft in, press fly against shaft with a broomstick (kvastskaft?) tack weld, and it should be centered.
Or ask a “bilverksta” if they have replaced any throttle housings where electronics is bad?
Sorry for the Swedish mix-in, im a little tired… 
Played the part of Hercule Poirot at a murder mystery dinner.
You may have blown your nose with black hands (happens a lot to me). Or, a hopper puff?
I have emptied the unit, can’t remember which time in order.
Do you get a lot of water out of a full hopper, JO?
It depends on what kind of driving. A full hopper of wood, 60-80 km, may produce 2 liters with a few condensing rest stops. Longer trips, when wood is consumed in one go and everything is warmed up, produce slightly less.
What are you looking for down there? It’s most likely nothing but the same as what you rake out from under the grate.
Maybe this new gasifier has just a slightly tighter by-pass above the grate. I remember you mentioned you slipped more char than you liked with the old gasifier. Does the new one slip less? If so, maybe that’s why you get constipated.
Yes, that’s also strange, I have the same grate but I think there’s a little carbon underneath, but it can’t be that much when I’m emptying it all the time. 
But I have to try to understand what the problem is, it went so well uphill the second time I was out, the old one has never behaved like that, tricky.
Edith: If I can’t get this sorted, I’ll have to try to hire a consultant from Bäsna.