Hi Jan, lots of questions here, how is the gasifier set up now for operation of measurements on the gasifier. If I counted right you have 6 nozzles.
How far are the nozzles to the grate?
How far between the grate to the gasifier bottom housing?
How far to the top of the restriction opening to the nozzles?
How large is your restriction opening 65mm still?
The grate looks good for opening slots.
Can you shake the grate?
How far from the top of the restiction opening cone to the grate?
The size of the opening on the removeable nozzles.
What RPM are you running at most of the time 1500 to 1700 and top rmps just under 2000 max still?
Are you preheating your incoming air some how from the engine exhaust?
How large is the firetube diameter?
Is there any way to know the operating temperatures at the grate or after the grate?
Sorry for all the questions but you are passing tar it looks like and bending rods. This means the gasifier is more than likely running to cold at the grate and not craking the tar or tary gases are by passing the restriction zone opening some how and getting by the grate. A likely place is at the bottom of the restriction cone is not sealing up with ash, this is a very important spot to get sealed up before you start up your gasifier. I packed it in with moist ash
I am just trying to calulate and help you figure out what the gasifier is doing.
It is a good gasifier build.
Oh one more question how much preheating around the fire tube, normal Imbert or WK gasifier jacket mantle?
Again sorry for all the questions Jan.
Bob
I am very grateful for any help I can get.
I thought about this the night before yesterday and think you are absolutely right it was a very stupid design, donât know if I should run more on wood before I redo this.
Okay I do NOT think it is a stupid design it is a good design that need to be tuned up right to stop making tar at this lower engine rpm. From what I can see it will work maybe with a little more heat into the intake preheating the air through a drop box maybe. I think you are using a clycone first filter on the gasifier?
Did you make a building thread site on this gasifier? Under what name, if you did.
I always think this way Jan, I can fix my mastakes and I make a lot of them. Lol
Can you show a drawing of this gasifier build with the measuements it does not have to be fancy and all to scale.
My formula is this for wood gasifier. Firetube large enougth to handle the wood size you are using.
Incoming air needs to be hot. By preheating the air.
Nozzles 6 or more and sized for the max air needed for the engines rpm.
Hopper wood pyrolysis reduction into the nozzle and from nozzles the now charcoal to the restriction open cracking of gases on into charcoal reserve and completion of the tar cracking on down to the grate.
The Hot zone from just above the nozzles down to the grate. Super white hot lobe below nozzles down to the restriction open and will pass through that on a hard pull of the gases with the engine but not through the grate area. This what I call over pulling the gasifier. Causing weak gases. The measurements are the tuning of your gasifier according to the demenions you have built. Like the height of the restriction opening to the nozzles or grate height or top of the restriction open to the grate.
Any and I say any gasifier can make tar. But fine tuning it is the key. And makes it easier with mor flexablity to not make tar. I have had my gasifier up to 1750 °f at the grate, and I know it is some where in the 2000 to 3000 °f up in the nozzle white hot charcoal lobe area. I have seen the melting marks in this area.
Lets just say I like it hot.
I know we can get this gasifier working making good clean gases.
Bob
No, I have a fiberglass filter on the Illern, and an ammo box with foam rubber as the last filter before the carburetor.
It seems to work pretty well, but I havenât driven more than about 6-8 hours yet.
I will run on gas until I get it home from the woods, and can rebuild the unit.
I tested the filter yesterday afternoon, I had 4 inches of water column on one side and 3.6 inches on the other side of the filter, at 2000rpm, could that be true on this little engine?
I donât see any soot to speak of inside the filter, so there shouldnât be any thickening of the oil or soot in the intake, now I just hope the filter doesnât get tight, Iâve only driven 50-60 hours yet.
I looked in the carburetor on the illet today, it seems too good to be true, will be interesting to see if it works as well in the long run.
There is no soot that I can see, but as I said only 50-60 hours of driving on gas.
That looks great Jan, totally clean 
Did you have fiberglass cloth in the volvo as well, or have you only had it in the cheva?
Hi Jan, in the volvo i used first rockwool, mostly trouble, very hard to pull gas through. At one occasion the car ârushedâ at a stoplight, it turned out to be a tuft of rockwool holding the throttle valve open, i then abandoned rockwool and used clay-balls (leca) instead, no good filtration, but i ran that poor volvo b20 20000km on woodgas, at the end the oil consumption was horrible, 5 liter a week, a good amount of that it left on parking spots alsoâŠ
This is ecactly why lm afraid of anything fiberglass of minareal based. Microparticles will be blown in with the gas and this is probably much worse to the engine thain soot or dust. Ist silica mostly, sandpaper abrasive!
Maybee if after it is an aditional oil filter?
Yes, i believe youâre right, no good for the engine, wowen glass-fibre seems to not drop very much âsmall stuffâ though, and a hot filter should best be followed up with a cooler, where light, flying, glass-fibre particles can act as condensation âcoresâ and that way be safely trapped in condensation water.
Or, as you say, a safety oil bath filter could be real good, if no condensation water makes a sludge?
Yes, it may depend on which fiberglass you use, the tests that the Swedish government did on trucks and tractors with fiberglass from the USA and later from Sweden, showed less wear on the engines than with pure diesel.
Oh no not again! Is it serious?
No, nothing happened now, I thought it ran a little strange when I drove it home from the forest, and this morning I looked at the valves, and discovered this.
Thinking about how it happened though, the valve is loose, no signs of tar, wondering if the valve was stuck when I adjusted it last winter, so the setting was completely wrong, or if the adjustment is too loose so it vibrates loose
JanA. The works always solution for minimal tars making is to feed the gasifier very, very dry pre-heated wood.
Your solution is in your picture. The forced air engine coolant fan. The shown metal flex piping engine exhaust.
Shown here in your video:
At 1:28 you show the warm-hot gasifier to downstream hot woods supply tube.
At 2:03 you show your long pathway metal gas cooling tube and your open sided engine compartment. Show again at 2:46 you show the opened sided engine and hydraulic pump compartment.
Re-jigger all of those to be drying metal gris baskets of wood chunks to de-humidify to be then directly dumped as needed into the gassier hopper.
Yes. I know I sound the smart-ass; the know-it-all. These are not just brainiac thoughts. Practices Iâve used that work. Sure it is more hands getting dirty work. Nothing of real value is ever done easily. You know this with your lifestyle chosen.
Nice clean engine internals you show. That takes frequent oil changes, yes. Success.
Regards
Steve Unruh
Iâm glad you take the time to help me Steve.
I donât think I have a tar problem anymore though, fixed it last winter.
However, am surprised that the push rod jumped out of position.
OH. I thought it was that you were expecting it to run with no wires on the spark plugs. I should have enlarged the picture. 
Hi Jan, just some thougts, do you have soot in your intake? A soot (klump-swedish) that suddenly comes loose, hold the valve open only one working cycle is enough for a push-rod to come loose, this often happened on some scania diesels when accumulated soot in the egr-system come loose.
Even water can do this, happened on my volvo once, when braking, even on them truck diesels, accumulated condensate in intercooler flushed the engine when struggling up hill, when let go down hill the water starts to drench the engine, this solution was bleeder holes in bottom of intercooler.
Edit: if i remember correctly the valve only needs to be hold open 2mm to give enough play for the push-rod to flex, and come loose.?
No, I donât think I have soot, the carburettor is completely clean (see picture above in the thread) and I take the gas through the carburettor.
I believe more that I had tar left on the valve so it remained in the open position after I adjusted, but am a little worried that the adjustment is quite easy on this valve.