Wow Richard, that’s some steady hand cutting you have , I would have bet my bottom dollar on that being a mass produced drain grate .
Well done mate .
Dave
3 Likes
That looks like a good working imbert setup , now if you can fit that in a small truck or car it might not need much grait shaking.BBB.
2 Likes
Not at all, Kevin, all comments are welcome.
Pepe
1 Like
Kevin, I would love a 1968 VW to convert. I had a 68 Karmen Ghia convertible. It was my first engine rebuild, it was running on 3 cylinders. Ran it for another 100,000 miles before the body started to fail. Damn, I loved that car, 34 mpg, too!
Pepe
1 Like
Kristijan, you’re a gracious host, seems I got a little carried away. It was a good conversation.
Pepe
1 Like
Pepe,
I hadnt had much time to talk to you guys for the last two days, but now that the freazers are full of steaks, bacon and sausages, l see lots of good talk was written!
Great desigh and fabrication! If l understand right the bottom grate disc rotates? How much char is slipt aling with ash at hrate shakeing?
1 Like
Hi, Pepe!
23. of December 2016
Answering Pepe on Pepe’s site… if Kristijan wishes?
Until then,
The GEK seems to be commercial — closed style.
The reduction aims more on passive sieving out gas, than arranging recirculation.
Not an experimenters “bench”!
I like your “topografic textile” woven grate; excellent gas separation, but prone to
destructive “burning”? How about ash separation?
Would work as a “jumping” sieve.
1 Like
Today l had some time to play a bit with the heart dimensions a bit so this is what l changed:
The nozzle cyrcle is now measuring 16cm insteadof 18cm.
The distance from nozzles to the restriction top is shorter for about an inch. Measuring 8 cm now.
This gives me a oxy zone of about 980cm3 or about a liter. Thats 6% of “secondgas”.
The other thing l have to take care now is the grate. I do lots of city driveing lately and my wife has a light foot when driveing so the ash accumulates in the reduction zone, then melts to a crust at harder pulls (wich are many as shown in the video).
Today l found the grate completely covered by a thick layr of slagy ash.
So if anyone has a idea how to solve the problem, advice is more thain welcome!
7 Likes
Merry Christmas, Kristijan!
Thank you, the video is much appreciated. I think we see about the same power. A slight up hill forces me down to 70 km/h too. Ha, I rev a bit less though. I see the best tourqe at 2000-2300 rpm.
About your ash problem. The only solution I can think of, apart from grate shaking, would be narrowing down the reduction bottom outlet. A 4-5 inch opening above the grate should keep the gas velocity up enough to keep the grate clean.
Also I think ash buildup has s lot to do with the diet. The gray alder I use has a high ash content and is no good for low end driving. However I haven’t discovered any ash melting. Lately I’ve run a high % of birch and I see no symptomes of clogging even with a lot of ideling and/or shut downs.
4 Likes
Thanks for the video Kristijan.
Wish you and your family the best Christmas ever.
3 Likes
White Christmas NOT. Thunderstorms and lighting when we should be having a blizzard. I’ll take the rain over the snow.
5 Likes
Kristijan, Merry Christmas to you and your family, thank for the drive though your country. God Bless you all.
Bob
2 Likes
My engine is preety dead below 2500rpm 
Good idea on the second restriction! I understand now what Max ment with double throat system. I think lll try that first.
I suspect l have a high silica content in my wood (it grows on quarz) thus nakeing those slagy clumps
3 Likes
I found a big, or shuld l say BIG crack in the gas suply hose today. No wonder l had problems. Fixed that. Then l found out my engines valve cover allso leaks air and since its connected to the intake manifold, this allso leans the mix a bit. Dissconected and blocked the hole in the manifold.
I redid all the connections with stronger clams to be sure. Poured water in the filter box, none came out anywhere.
The resault? I never injoyed the drive so much. I was so happy l bought the most expensive sticker in the country, a years allowance for all motorways in our country, and went for a ride on the all mighty motorway l feared to DOW on before. I was cruizeing on the highway at 110 kmh for about 5 km, then l burned all the fine char in the charbed and speed was down to 90kmh.
A good day indeed!
So l learned a couple of things today,
-if something doesent seem right, check for leaks.
-highways are indeed possible with such a small gasifier, but much smaller wood chunks are neaded. I wuld say wallnut size compared to cigaret box sizr for city driveing.
-Its nessesery to shake and poke the charbed strongly at motorways. The road is so smooth, l saw a wormhole in the charbed when refueling, goeing stright down to the restriction.
- l drove for about 50 miles, and the petrol guage stayed put. I drove home trugh more “city drive” roads with more shifting and trafficlights, the guage started moveing. This does confirm the suspecion that the engine sucs petrol in at low throtle. What to do about it is a matter of some deep thinking (ideas wellcome)
Ps l allmost forgot; driveoff from a longer idle is allso possible with much less hasitation now
6 Likes
JO´s 8” gasifier
Projects
Kristijan LeitingerKristijanL
6d
Haha l shuldnt realy laugh either l spent the last half a hour shooting at shadows too in terms of reintroduceing my brain with math once again
Ok conclusion? Our hearths are too big 
Now we have a problem. If we set the restriction higher, we loose the 60° char slope. So, we have to make the nozzles longer. Myne are screw in but the question is wuld the protrudeing nozzles affect the bridgeing of wood chunks?
Allso, if l remember right, the reduction zone shuld by the book be one third of oxy. So thats just about 400ccm?? This seems aufall small…
@gasman, wuld you be so kind and show us your heart dimensions? I think you did before but cand find them…
Jan-Ola Olsson (SWEDEN)JO_Olsson
6d
1
Now we have a problem. If we set the restriction higher, we loose the 60° char slope. So, we have to make the nozzles longer
I don’t think so. A 60 degree slope only climbs about 8cm with our restriction and heart diameters. Hm…the 400 cm3 sounds like fire in the dump.
Kristijan LeitingerKristijanL
6d
Ok then. I tryed building “by the feeling”, now lll make heart dimensions “by the book”. Lets see what happens. Ill report the day after tomorow, tomorow is a big day, two 300 kg pigs to put in the attic and freezer. Althugh this debate fired my curiousity to a point l might set the dimensions today.
Jan-Ola Olsson (SWEDEN)JO_Olsson
6d
Althugh this debate fired my curiousity to a point l might set the dimensions today
Fired my curiousity too. Springtime it is
Max Gasmangasman
6d
Hi, Jan-Ola & Kristijan!
20.12.2016
I lost my text size and can hardly see any text. I don’t know how to resize back the normal text size.
Desktop and ff page (google) are normal, only this Forum page is gone mad!
I don’t know, if somebody has payed me a joke or what is going on!
Chris SaenzChris
6d
Press Ctrl-0, Max. That’s a Zero not letter “O”.
That will reset the zoom controls.
Wondering how I did that? Like this:
Some really big words.
Max Gasmangasman
6d
JO_Olsson
Hi Jan-Ola & Kristijan!
20.12.2016
There is no established rule over the oxidation volume; it is up to estimation,
In Sweden, during WW II the big trucks and busses with 7 – 11 liter motors
and beer-can sized fuel used 11% of the “second consumtion” as the Germans
express it!
Sekundenverbrauch!
DJ used 4% for his small grass clippers, and so on…
With a commercial volume calculator it is easy to “nail” the cut cone volume:
www.calculatorsoup.com2
Conical Frustum Calculator
Calculator online for a conical frustum. Calculate the unknown defining surface areas, heights, slant heights, circumferences, volumes and radii of a conical frustum with any 3 known variables. Online calculators and formulas for a conical frustum and…
Hope this easies the estimations!
I was earlier describing the reduction in a long cylinder making both the oxidation
and the reduction with just the restriction plane in between them.
As the diameter is about 2 - 3 times the restriction opening, the down-blast will
activate an up circulation along the side-walls back to the blast beam…
Kristijan LeitingerKristijanL
6d
Max,
Is this upblast cosiderable? The reduction char cone in my gasifier is surrounded with a mix of charcoal/dust so l dubt much gas can break trugh that or am l missing something?
Have you got any suggestion on preffered reduction size?
Max Gasmangasman
6d
1
Hi, Kristijan!
20.12 2016
In a wide cylinder with unclogged char it would be modest, in your case it seems to be
non-existent, as it looks more like a straight tube in the char down to the grate-slots.
No, the decisive factor seems to be the free outlet area in the grate.
A wide, lazy grate needs mechanical action, sieving or shaking to allow flow through.
A grate with smaller passage area ~about the restriction area, is completely dependent on
on high draft as on open road, and starts clogging in town traffic.
If a grate is not only letting gas and ash through, but like in Imberts, letting the gas
out sideways, the clogging is not as much a short period problem.
The “all through” type is more critical. It also works better with smaller reduction volumes,
which can be kept cleaner from settling ash. More like the type you are using.
But trimming is critical and needs more attention.
Max Gasmangasman
6d
1
KristijanL
Hi, Krisijan!
21.12.2016
Hearth tube DI = 210 mm
My oxidation is ~950 cm3,
5% of 19 l/s
Nozzle-tip-circle 160 mm,
4 nozzles, hole diameter 8,5 mm
Silo funnel makes a ringbalcony abowe
the nozzles for sucking and collecting
pyrolysegases
Jan-Ola Olsson (SWEDEN)JO_Olsson
6d
Max, what about reduction volume? (dia/hight)
Max Gasmangasman
6d
2
Hi, Jan-Ola!
21.12.2016
Vast! Full diameter. ~420 mm X 30 mm from “grate” up to the lower end
of the 210 mm tube. = 4,156 liter.
In the tube 210 mm X 100 mm. (upwards to the restriction plate)
= 3,4636 liter.
4,156 l + 3,4636 l = 7,6196 liter.
There is more (insulation) char outside-upward the 210 mm tube!
Works well for 700 – 1000 km,
when it is time to shake and clean out the low ashbunker.
The good part is, that it does not behave differently on any power level.
Fast response from idle to WOT! No delay time.
Still, it needs an angeliron grate!
Max Gasmangasman
1d
3
JO_Olsson
Hi, Jan-Ola!
25.12.2016
A late answere to dec. 20 mess. 651:
Jan-Ola Olsson (SWEDEN)JO_Olsson
5d
1
gasman
Just for reference: The Audi “Imbert” has only 5% upper hearth volume (cut cone) of the net gas consumption per second at WOT on motorways! (3500 RPM)
I’ve never done any calculations, but now that I do they suggest my gasifier is almost down to 2% ???
I did it this way:
1800/4×3500/60
That’s 26250 cm3/s.
(fault half the cylinder volume of gas, every other stroke, times rpm/60 fault).
That is so far one cylinder full filling/s, each stroke.
Divided by two for 4-stroke, and by two for 1:1 mixing
26250 cm3/s : 2 : 2 = 6562,5 cm3 net gas/s for one cylinder.
4 cyl. X 6562,5 cm3/s = 26250 cm3/s
Times a realistic filling factor 0,72 = 18900 cm3/s!!!
For all cylinders together…
Why not use the practical formula:
l X n X 3 = ??? Every stationary factor is there, you only
need to give the displacement and n = rpm:1000
…
My upper heart (nozzle tip to restriction) cut cone volume is 556 cm3.
556/26250 = 2.1%
What did I do wrong? What’s the proper way of calculating gas consumption?
…
556 cm3 : 18900 cm3 = 2,94179% ???
I still doubt that…
Have you used Conical frustum calculator?
(Observe they want radius, not diameter)
Jan-Ola Olsson (SWEDEN)JO_Olsson
15h
still doubt that...
Hello Max,
Read a few more posts and you’ll discover I was the one that messed up my calculations.
I was fast, but wrong. I accedently punched in the cone hight in inches.
Kristijan and I finally came to the conclution we both had an upper heart volume of around 10% of “sekundenverbrauch”.
Kristijan LeitingerKristijanL
15h
Hi Jan,
You mentioned you dont touch the a/f valve at all while driveing.
So, you set it when you startup and thats it? Idle, highway, all the same setting?
Jan-Ola Olsson (SWEDEN)JO_Olsson
15h
1
Yes, that’s pretty much right.
I squeeze it when I pull gas up to the motor. When out on the road I might try lean out to where I feel I’m starting to lose power and I back off from there just a little bit.
Edit: When pulling really hard, climbing a steep hill, I might try richen the mixture a little bit.(I know I have some small leaks in the hayfilter rubber fittings that will show at hard pulls)
Kristijan LeitingerKristijanL
15h
Ok got it. Thats preety cool. Seems not much more work thain with aautomixer.
Im thinking to go back to cable. The automixer is very picky on gas quality. I think if l culd set it richer in city l might just get away without pressing the hybrid swich so often.
Max Gasmangasman
13h
2
Hi, Kristijan!
26.12.2016
Actually, the autodispenser is not picky, provided that both flaps
are opening perfectly identical!
I have made several of them, and had no trouble
with either small or big ones!
Perfectionism in this case is rewarding in a grand way.
0,5 mm versus 1mm at opening makes a mockery of whole the
ratio demand!
They have to close and open identically, absolute! Basta!
When closed, you shall not see sunlight through either throat.
Kristijan LeitingerKristijanL
13h
Max, twinflaps are no longer installed. I use the original one flap throttle body now. The cars computor didnt like the absence of throtle position sensor.
But l see no difference between twinflap throtlebody and the original single flap. Its just that there seems to be something wrong with the entyre air/gas mixing assembly. I think the membrane is too slow too. Ill try to make things better, but first, for the time l fabricate, lll try the manual gasmixing.
Max Gasmangasman
11h
2
Hi, Krisijan
26.12.2016
I am lost about any diaphragm functions with so far unknown modifications.
One can use the gasoline-air throttle body for air, making use of the flap position reader and letting in woodgas below this throttle body through a Y or T piece! Preferably spiralling.
The woogdas throttle body must however be identical by geometry with the gasoline-air throttlebody.
Then they are ganged together when using woodgas, separated when using extencively gasoline.
The gas-side of the membrane connected just ahead of the woodgas throttle, the air-side just ahead of the gasoline-air
throttlebody.
Still further ahead of the air sampling point comes the arriving pressure balancing flap operated by the membrane.
This flap can be 1m or more ahead of the air sampling point and the gasoline-air throttle-body!
If the gasoline “delivery” is sensitive for the balancing “vacuum”, made by the membrane-operated flap, then the gasoline must be cut-off when driving on woodgas.
This makes a simultaneous two-fuel drive hard to manage.
1 Like
Congratulations Kristijan!
110 km/h - that’s not fair
Is this with or without the automixer?
Your engine is definetly better suited for woodgas than mine. Cross flow and 4 valve pay off when it comes to power. I wonder what kind of power you would see if you were able to advance your timing as well?
About the gasoline consumption. What about a manual shut off valve?
2 Likes
JO,
Thanks
But like l sayd, this was momentairly power. 90ish is more realistic. At least with biger mixed fuel.
Yes, with the automixer. With a better sealed system it runs fine, but it is still mideratly picky on gas quality.
Well my engine is rated for 109hp on dyno, yours is 80hp if l remember right?
The timing advance is a hard nut to crack. Only if changeing the softwere in the computer culd l advance it.
Hmm perhaps a electromagnetic valve in series with the fuel pump swich… maybee…
2 Likes
Max, right now l have a Y type mixer with the membrane commanding a air valve on one limb of the Y, and the gas connected on the other. It works well enough IF the air inlet to the gasifier is open full to alow the steam to escape at a stop, not createing a pressurized gas suply sistem.
This way idles are possible for more thain 15 min.
2 Likes
Hi, Kristijan!
27.12.2016
On what date or message did you mention 110 km/h?
Your Y-connection leaves a lot of uncertain details;
is the gasoline throttlebody in one leg to give air and flap-angle data to the computer?
Is the gasoline air-throttle ganged to the woodgas flap?
As you have observed, the gasoline throttlebody is necessary to satisfy the computer’s need to calculate the air-intake at all rpms.
This in turn sets the gasoline delivery, fine adjusted with the Lambda signal, when the Lambda transducer is at working temperature.
Bringing in the woodgas after the gasoline-air throttlebody
is just a way to change fuel; everything else works like it used to be with gasoline and air-flap reading!
Dispensing equal amounts of woodgas as air, keeps the Lambda happy; it only reads the O-content in the exhaust, it does not know anything about what fuel has consumed the oxygen!
The only questionable thing is: Does the gasoline “delivery”
become affected by the small vacuum
the arriving air-pressure membrane-flap executes?
(= gasifier vacuum; no woodgas use = No vacuum! )
Partly used = part vacuum.
…
On “clean” gasoline drive, you just detach the gas-side sampling hose from the gas-sampling point and let it “sniff” atmospheric pressure via a 3-way valve.
(Perhaps) unnecessary as there is no woodgas underpressure!
…
The ganging connection to the woodgas flap must also be interrupted.
These (two) things can be performed at the instrument panel
with traditional Bowden- or Vernier-cables.
This also enables mixed fuelling; manual woodgas setting
0 — 100%, with adjustable flap ratio,
Lamda sets the gasoline-part according to oxygen content.
Haven’t we had it already in some form?
Chris has made a LEGO video of the flap-ratio mechanism.
…
Still, put back the back-flap on the gas generator and an-other one
in the motor compartment blowing into a water+open-cell foam bucket!
2 Likes
Happy New Year, Kristijan!
5.1.2017
Tell about the new Y-version!
1 Like