Been thinking about what I said yesterday. I need to start off that theory by first saying that “tar must be burned out while going through the restriction”!! If it is not burned out there is will join with the water vapor as it condenses and continue up to the engine where it meets with hot parts that boil off the water and the tar grabs onto the exhaust valves. Over night the hot tar cools to a thick gooy stuff that will stick the valve stem. If you burn the tar at the restriction, then as the hot gas is cooled, it will only produce water as a condensate… This brings up the question, how do we increase the temperature of the gas going through the restriction. — larger orfices in the nozzles/ small? How about the restriction-- bigger or smaller. Or is the answer in the reduction area. TomC
This is exactly what bothers me! Judgeing by the slag l produce instead of dusty ash, and bent restriction planes, l can say my gasifier runs allmost too hot.
But this discussion triggered me to think where tar culd be produced. I thod of cooldowns. At cooldowns, tar culd produce and condensate in the system since l dont close the pathway to the engine at cooldowns. The hopper is hot hours after l stop the engine!
What i meant was the head gasket it self could be pushing just small emount of compretion intoo the crankcase.you wont find it with a compresion tester, you need a spark plug adaptor too hook 150 pound air preasure from air supply one cyylinder at a time while both the valves are fully closed. Then rotate the motor till next cylinder has both valves closed. Exoust valve leak will exit manifold. Intake valve leak will exit up through intake manifold.radiator or coolent leak would buble in radiator, and last possible leak air would be seeping out rockers or dip stick hole. I dont have the adaptor though the job i had at a garode.that is the best method for head gasket inspection with out takeing or before takeing apart for new gasket. You probley all ready new that procedure?
For blown head gaskets just take the radiator cap off and let the engine idle. If the water in the radiator bubbles you have a blown head gasket. No bubbles equals a good head gasket. TomC
If the gasket is blown between two cylinders there will usually be no bubbles . But should be able to detect a gasket leak as Kevin says with high pressure air and compression gauge .
OK l burned a whole tank of dino this week, no DOW (one of the saddest weeks of my life- no kidding 
) and l was geting prepared to tear the engine apart, do a valve job, maybee replace pistonrings etc, then slowly the performance got better. The gas comeing out of the crankcase vent was down to minimum, power better. Didnt measurre compression yet, or test it with a air compressor, but l plan to.
So, l decided to try DOW agen. Good performance once agen, tested it without the alubox on local roads. Ran wery well.
Then l drove to work with the alubox on, good performance untill the system heated to temp. I know this phenomenom from before, so l suspect a airleak on the hot part of the assembly.
l think l read someone here tested the airtightness with a smokebomb. Any ldeas who culd that be?
Ha! Kristijan, I knew it! Once a woodgaser, running on dino really hurts 
I’m glad you’re back in the saddle.
I think a lot of people here tried smoke bombs. I did once, but only to check if my dump seal was tight. Filming down the housing looking for white trails is another option.
Hi Kristijan
I read that a HHO kit helps a lot to clean the engine
Tom and Kristijan. On the tar must be burnt up in the restriction think of what you are saying.
You can only burn-up, combustion Convert tars in an oxygen rich environment. Only combust them in the oxidation zone from the nozzles front down to just ABOVE the restriction. Restriction and below is supposed to be an oxygen deprived environment.
Tars making it down to the reduction zone would be reduction area heat robbing vaporized; to condense out later down stream.
A great part of the devil is in the details is how above the nozzle hieght volatilized out “tars” are heat/time refined down and fully combusted Before reduction.
Not so hard in a continuous load situation like a petroleum refinery; a narrow range wood stove, a constantly loaded stationary generator.
It is the Needs over a 10 to 1 turndown ratio that makes this so difficult in a vehicle gasifier.
How WayneK has year after year, step by step evolved his system to handle upper system tars three-ways-but-Sunday is the overlooked “99% perspiration, 1% inspiration” of his system.
J-I-C Steve Unruh
Sorry guys for the blackout, had a few setbacks the last few days, but now lm back.
Thierry l have mixed thods about hho. Quantity is what concerns me. I dubt 200ml per minute of HHO will do much good in a engine that suks in about 2000l of air per minute… but this is just a guess.
Steve, how does tar react later down stream? My thinking is it must allso crack to a point on contact with hot coals/ash or am l mistakeing?
Anyway, some update; still burning petrol 
the engine now runs well and smooth agen, no more smoke trugh the crankcase vent, oil stays clean and l measured the compression today being about 11bar on all cyls, wich is a lot better then 10,8,10,7 l measured last time.
I had problems with the woodgas asembly lately, drove well(ish) when cold, then power down and cooling rail temp up. Indicated a airleak in the hot part of the system so l pressurized the asembly and found a big leak on the cyclone fitting. I allso dissasembled the cooling rail, and half the tubes l found it plugged with soot.
So time for a rethink. I have some ideas on changeing the desigh of the whole asembly, top priority make it lighter and with a bigger hopper space. I think doubleing hopper size culd be possible with some modifications.
Good to hear the car is ok. Not so good to hear about the gasifier. I guess you could weld up the air leak but what about the hot filter? Are there damages to the fabric?
I have read that until woodgas is below 600*F CO will react to become CO2. This frees up carbon (soot). Is it possible that the smaller cool area you have to use might be causing this to happen? I did see some WW2 systems used a cooler under the car but they probably had more ground clearance
Fred
Hi, Kristijan!
1.3.2017
If you dare show a smooth row of coolertubes all around the (now removed) aluminium case, 3 rows of tubes on all sides makes the innards invisible from outside. Di = 20 mm, spacing center to center 30 mm.
Bottom “plate” 2 ash boxes; one for the hearth, the other for the cyclone. Perhaps a third for the filter.
The cooler has a rectangular ring connecting the tubes in the upper end and a likewise rectangular distribution ring in the lower end.
Neat and regular, looks still “boxlike”, I hope.
Whole the “box” with a common neat cover, as before.
The main top cover will hide the cooler “frame” cleaning lids on the upper side of the rectangular gas-collecting frame.
The ash boxes horizontally inside the cooler rectangular condensate frame. Lids opening downward.
Just another fast idea…
Fred, the cooler normay works well. It cools the gas to just above ambient temp. Unless there is a leak, causeing for a small part ofgas to be burned, heating the cooling rail and giveing lean gas.
Culd you explain the cooler idea a bit more plese?
I am thinking to go with a ss 0,5mm wine canister for the hopper. Wery light and durable.
I forgot one thing… l did take a look at the cat cnverter. It wasnt plugged at all. In fact the opposite, it burned out clean. Not to big of a problem, althigh l am thinking peaces of broken mesh culd plug things later in the exhaust. Any hods?
Good. I was worried having the last post, then silence.
Of course running HOT complex hydrocarbon chains across HOT glowing woodchar and exposed mineral ash will result in chains “cracking” to shorter chains. These would only be a motor capable fuel if kept, hot and gaseous. Making for an IC piston engine damaging condition. Hot gaseous fuel burns the valve stem and cylinder walls lubricating oils. Yep. Had to try.
Cool these and liquefied fuel chains could be made. Along with sticky waxes and such. Again engine damaging without a separating out system. Will be very down stream components coating with each fraction coating at it’s condensation point…
And true wood “tars” do have oxygen molecules in them. Making for a confusing, changing lower-reduction section set of conditions.
All in all; for IC piston engine power better to first as much as possible mid-system oxidize all tars to convertible simple gases of HOT CO2 and water vapor. Tie up the oxygen’s in these for hot char to CO conversion.
Save the cracking/liquids reforming for a controlled stationary system refinery.
Many I’ve know woodgas for the hope of making methanol for their seed oil heavy-fuel oil compression ignition engines.
Futile pursuit for personal DIY power.
Too many steps. Too much complexity. You will become a slave to your system maintenance’s.
Compression engines can be made to burn clean, seed and waste-ag oils fine, neat. No need to make-like-spec-deisel fuels needed. Elsbett engine convert the compression ignition engine instead. Dutch-German.
Woodgas directly into spark ignition engines is even more simple, direct use.
Then use the engine’s shaft power for almost all power needs. Use the engine heats for heating power.
Hit the critter in the head with a hammer. Hoist up. Bleed out. Meats then. ALL eat.
J-I-C Steve Unruh
Thank you, Steve!
2.3.2017
Good rehearsal of 1950 Gengas! The Gengas though did not emphasize the importance of nozzle-tip-circle initial blasting to acheive the process temperature early enough on the way down toward the restriction! Imaginary vertical velocities on the low side.
This is important on part load. Nor did they mention collecting pyrolyse gas under a collecting “balcony ring” formed by the silo funnel.
New times, new observations…
Hi, Kristijan!
2.3.2017
Doing things in a haste; goes often wrong!
Now, the raster for the thin cooling tubes should go in a 60* fashion;
that makes for D = 20 mm (on a paper) horizontally center to center 25 mm and vertically (between the row-lines) 20 mm.
3 rows, the row-lines this way 20 mm apart makes it impossible to see what is inside the “tube-box”.
The lower and upper rektangular frames are made of square-profile, thin-wall tubes. Approx. 100 X 100 mm.
Hi, Kristijan!
2.3.2017
A correction (again) , with my assumed measures, the hole-center pattern will be slightly over 60 degrees. But it is not critical; the main point is to do a consequent and regular pattern.
What is critical is to keep the distance between the center-row lines exact as a tube diameter; in this case = 20 mm.
Ha! Ha! MaxG three fellows now we in common know who have, "coolect(ing) pyrolyse gas(s) under an (overhanging) “balcony ring’ formed by the silo funnel”
When I pointed this befit out to two of them setting up the conditions for constant recycling/refining, they did not acknowledge/understanding. Insisting their overhanging ring was just for fuel particle flow guiding.
An old saying here in America is; “better to be lucky, than good”.
I hate this fatalistic saying. Lucky leads to non-replicatable, sloppy thinking/designing.
I much prefer; “persistence, pays dividends”.
Thoughtful observations is the basis of all forward advancements.
Regards
J-I-C Steve Unruh
JO,
Im sorry, l missed your post completely. The fabric seems ok. Its a tough thin. Allso, eaven if there is a small airleak, nothing catastrophic happens to it (exept bad power). If the leak wuld let so much air in to light the soot on the fabric… thats a different story.
Max, l think l get you now. But this lowers the bottom to the ground doesent it?
If you find the time, perhaps a skech?