Could it be nozzle size? Like trying to run while breathing through a straw?
1 Like
Good morning JO,
You may want to check to make sure ash has not accumulated up to your grate and if so empty ash and char,
You can also use your poke rod and with a twirling motion drill down to your grate and find a few holes and push your rod through . Also peck on the grate but try to avoid letting wood chucks fall in.( leaving a void.) . The intent is to give the air a less restricted path to the grate area.
With gasification it seems to be a balancing act between constipation and diarrhea and will take some time to learn the proper diet vs work .
Just remember with constipation there is poor performance .With diarrhea there can be poor performance plus components can get dirty . 
3 Likes
Hi, Jan-Ola!
16.of July 2016
Your fuel seems to be OK (for the moment).
You mentioned ? that the pressuredrops nozzles/bed are 1:10 ?
In such a case it is useless to modify nozzles Before the lower part = the fuel bed is “under control”.
Shake the grate and raise it considerably, until the pressure-drop ratio approaches 1:2 – 1:1 region.
Observe the grate temperature if possible.
Test driving aswell.
You mentioned too, that the nozzle pressure could peak 4" H2O.
That is OK, until the bed resistance is getting normal.
When the bed resistance is normal, it will be time to reassess the nozzles as earlier mentioned…
These two resistances affect each another, but getting the lower one in order is the key to get them both in order.
2 Likes
I’ll try get some vacuum through the char up to the ones I have first 
That’s what I do every lightup and let it burn a void. Runs good for a while but keeps getting constipated. After maybe 100 miles driving I only had a couple of handfulls of small char in the dump and a two cups of dust in the cyclone collector.[quote=“gasman, post:203, topic:1928”]
Shake the grate and raise it considerably
[/quote]
Picked up wood and char almost down to the restriction this evening. (Char below nozzles is really small. I might have cruched it some while scooping it up but is it possible to have too good of a monorator effect?). Tomorrow morning I’ll dump the rest downwards and raise the grate further up into the reduction tube.
2 Likes
Hi, Jan-Ola!
16.7.2016
As the lower part, reduction part is too big (by volume) it cannot consume the char with the available heat energy the upper part, oxidation part is offering.
That you can clearly see from your own experience; as you have seen, it gets worse with low power outtake and gives a slight improvement at full power!
Reduction needs heat energy!
It has gone so far, that even the upper oxidation part is now “consuming” the char which should be delivered to the proper reduction part below the restriction…
Don’t worry, it is just a matter of adjustment!
But as my former pupil DJ says: Gasification is FEMALE!
Nothing works, if the lower part is not satisfied…
For later consideration: What is the diameter of the restriction?
5 Likes
I’ve heard about the female mind beeing simular to a gasifier’s, but what you suggest puts things in a new perspective Mine has a 3 inch restriction
2 Likes
Thanks Jan-Ola!
17 of july 2016
A perspective should always aim at something meaningful?
To do meaningful calculations: What is the RPM at 100 kmh on the highest (5) shift? Motor 1800cc?
Like my Audi 80
I am preparing to calculate your upper hearth volume as a part of the max gas consumption per second.
This percentage part is chosen in accordance to the fuel-size.
For successful Volvos 2,3 liters and half cigarett pak sized fuel it is confirmed to be about 7%.
2 Likes
Without testdriving I remember 50mph (84 km/h) was 2000rpm, so 100 km/h should be close to 2400rpm (2381). Yes, it’s a 1800cc.
2 Likes
Hi,Jan-Ola!
17. of July 2016
Thank you! Audi 80 has about the same motor 1,8 liter and on the fifth gear 100kmh gives 33XX RPM! 1010kg.
Can you confirm?
1 Like
Hi, Jan-Ola!
17. of July 2016
I meant confirming Rabbit RPM on 100 kmh on the fifth gear!
1 Like
Yes Max, confirmed.
Opened up the bottom of the gasifier this morning. Discovered signs of a small wormhole at the end of one of my auger pipes. Patched it up.
Raised the grate 2" up into the reudction tube, put things back together and went for a ride 
In the video I keep talking about inches of vacuum. My guages are mbar. 100 mbar = 40 in H2O.
The battery in the camera died after a while but after holding it down for a couple of miles I seemed to be able to burn out some fines and ended up with a 4:1 to 5:1 vacuum ratio.
I think I’ll leave it this way for a while. I can cruse at 60 mph with half the vacuum I pulled before. At 50 mph I pull less than 10 inches at 1/4 throttle. Outgoing gas temps from the cyclone are 30% higher than before and peaked at 300 C (572 F).
11 Likes
Thank you so much for the video on your gasifier rabbit light up and drive in your country side. A little taste of your Beautiful Country on the other side of the Great Waters. Keep on Gasifiing.
Bob
3 Likes
Smok’in!! That looked and sounded great. Pretty country, pretty dog, pretty wife, and awsome VW!!
3 Likes
Yeah, most are pretty, except me and the VW
1 Like
Sorry Max, looked at your numbers again. Did you really mean 33XX rpm? Mine gives 23XX at 100km/h, close to 2400 rpm.
1 Like
Hi, Jan-Ola!
18. of July 2016
Yes, Audi 80 has a reliable RPM meter in its dashboard.
I still am curious about your low rpm at 100 kmh on the 5 'th gear!
If your’s OK, then it is designed to come home empty very economically after transporting a heavy load to “the market”, probably on some lower gear…
Another “Shocking” matter: I just calculated the volume of your hearth; it seems to be 1,67 times bigger than optimum on your admitted RPM for 100kmh… and egg-sized fuel.
Don’t worry, it can be “compensated” with taking off in the reduction end and using a bit bigger fuel and a few details.
Don’t rush in anything yet.
Satisfying the low end first… probably 1" more off.
How much is left after one more inch is taken off?
Another question: What is your nozzle-tip inner diameter?
1 Like
Hello JO .
What Carl said .
Thanks for the video , You look good wearing a smile .
3 Likes
Tank you all for your kind words!
Max, below is about current situation:
Went to visit my sisters at their forrest lake cottage last evening. 60 km on gravel roads. I was afraid charbed would get compact but instead I got 3:1 readings. Engine seemed to like it but gas temp climbed more easily. I think I’ll stay at this grate height for now.
1 Like
Thank You Jan-Ola!
18. of July 2016
Good results!
But, also the nozzle-tip inner diameter, (hole) ?
What is the condense water temperature under the cooler at the end of a longer road trip?
Have to re-calculate, as the nozzle-tip circle has been reduced… getting better.
1 Like
Nozzles are 7 X 7.5mm ID.
Upper part of the cooler is always ambient, but I haven’t caught a drop of water in the tank yet, only dry soot powder. Hay in the plastic barrel is moist, but no more.
Hopper however cathes about 2L every 50km.
1 Like