Here is a picture of my angle iron basket grate that I made for my S-10. It seems to work pretty good.
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Good morning don
Does that grate sit up tight to the fire tube so that only small char can pass through the bars? Or is it still on chains with somewhat of a opening above it?
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It hangs on one link of S hook “chain” about 3/8" to 1/2" below the fire tube just enough to allow some swinging movement but not much.
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open link? I was surprised I melted the closed link chains on my grate, gotta be some crazy temps down in there!
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So far so good! ! ! !
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If the hot lobe moves down into the restrection opening and on down into the charcoal reserve area. This is where you can use up your charcoal reserves and then go into heater mode. The lobe of the burning charcoal can reach very high temperatures that can melt metals. What was protecting the chain? Nothing. And it was not a very big link chain to start with. The long pulls up the steeper hills are going to need some help.
Keeping the big charcoal from slipping off your grate will help a lot.
Picture in your mind the white hot lobe 2500°f to 3000°f at the restiction opening on a high vaccum pull. Now the charcoal that is holding it up slips out from under it and off the grate and this keeps happening, now where is the hot lobe it has slipped down too. If the charcoal would have stayed there the lobe would have stayed where it was. The higher the vaccum pull the worst it gets. More air is added at the nozzles.
Like many have said it is a balancing act when running a gasifer.
Until you have more time after your move with the family keep a lighter foot when driving on wood. Run on gasoline when going up the long steep hills you have to climb. Yes you will use a little more gasoline. And for now clean out the ash/charcoal more often.
Bob
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I’ll put this reply here since it seems to pertain to my truck more then others
Steve made mention a few months ago on old growth haveing the same burn intensity in a wood stove as some of the better hardwoods and I agree, the old growth is a very sought after firewood in my area, calling for a premium price. I once sold a chord of Doug fir old growth deliver to downtown Seattle for 500$. And it got me thinking, now I just check a few pieces here and there. Each grain structure from pine fir or cherry will chunk differently, I can only guess that means it will release it’s gasses differently and may need to be chunked differently size wise. Maybe that has something to do with my larger char getting past the grate, my sawed chunks like I said we’re smaller in size, maybe I just need to downsize my chunks all together and see what happens. Full clean out yesterday hay filter wash down, cooling rack rinse, char cleanouts before I left work, just rolled into work and vacuum is back up to 20/1 and sucking gasoline. 70 miles. Each variable…size of chunk, species of chunk, growth ring tightness of chunk, grate height, temperature and overall pull on the gasifier, any one or combination could be the reason I am slipping large char. I think Wayne is definitely onto something using one species of hardwood, a more consistent fuel supply where as I’m running whatever I get my hands on. I am tempted to go back down in restriction size, maybe see if that helps. I only ever had this clog 2 times with the six inch restriction and using the same muttly mess of wood species and density’s. Maybe the restriction was holding the chunks back and up long enough to break them down to a size that wasn’t causing the clog problem
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It is worth a try, Marcus and simple. The 6" restriction opening will in crease the velocity/frequency at that point.
Heat will increase this will help with the reduction of the size of wood. How much power loss is the question. You will not have to worry about making tar, it will be converted into energy.
This is where Al Frick @trikebuilder57 hopper lid designed to drip some of the tar condensation back into the center of the hopper top for more power. Keep it real hot at the restriction zone and above. You will still have your charcoal reserves below for the hill pulls. Just might be a little slower in top speed.
Now you went from 6" to 7"? Maybe 6.5" will the sweet spot for your gasifer.
Yes the size of your wood is very important and the species of wood. Soft, hard, and in between woods do make difference on what size you need to cut.
This is just some more of the 75% in gasification that we all keep learning.
The rings of dencenty in wood, I like that observation you made of old, and new growth on the hardness of the wood and age. Maybe more BTU’s performance?
Bob
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I don’t know what the speed change would be, surprisingly I have lost top end performance with the larger restriction. With the six inch I was able to tickle 80mph, with the seven inch both down low and now raised up it’s 60-65, unless I’m clogged up and get some gasoline. I also appear to have lost some bottom end as well, when vacuum is 2/1 it is very sluggish untill about 2500rpm. It is very interesting 
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Remember one change at a time. Very important.
Bob
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Maybe for the time being try using smaller wood chunks, if that improves leave the 7" in. If not, try 6.5" with the same small wood chunk size.
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I agree with Cody…
Bob
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Problem is I have been chunking larger and larger, thinking the larger pieces would help with char bed clogging up which does happen often now for some reason. And with sifting my wood as it gets chunked I have very little fines of wood in the system. Hence thinking a restriction change is my current best option untill I get all this larger chunked wood used up
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Okay I see what you are talking about. Then do the restriction change. But you might go with the 6.5" and see how it works. 1/2" is a big change in a restriction opening. It is all about fine tuning your gasifer for your needs and driving conditions. Certainly not mine or anyone elses.
Bob
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But your car went well from the beginning, right?
I think a thread like this is good in the sense that I can go back and look at what I have done for changes, and possibly find out what has happened, and when the error started.
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Precisely Jan, this is a log book. I still go back and look at what I have done on my 92 Dakota truck thread.
Bob
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It ran phenomenal from the git go, great bottom end, good top speed but has always used more wood then I expected it to. Waiting for summer time with some very dry wood to start measuring pounds per mile, right now my wood supply is very inconsistent in moisture content. Other then using lots of wood compared to other doers numbers, it ran far better then I expected, one reason I was so hesitant to change the restriction. I think I went about 3500 miles before I changed it
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Now I do not know much about this yet, but from what I understand the wood consumption decreases quite a lot the more preheating in the air you have. I do not know the effect if it follows the same curve, I think it has a lot to do with the size of the air supply, the hotter the air the less oxygen, but can be completely wrong as I think.
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This is something I have not found discussed very much, we talk about preheat more for wood drying effect, I had not heard anyone say it reduces the amount of oxygen that is a interesting idea. Heat expansion to displace or maybe “loosen up” the air molecules. Getting into big words for me I’m not a science terms understanding kinda guy, but I see the premise of what your saying
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It’s why you use an intercooler for a turbo, makes the air more dense.
Preheating the air makes it less dense
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