Print

[hondaracer2oo4]

Well from your description of what you have when you open the firebox door it sounds like you don't have a right side up fire which is good. So if you have lots of a smoke(fuel)
And you have a good hot coal bed producing that smoke than what your missing is the right mixture of fuel to air. I agree that your nozzle size may need adjustment to get the right mix

[coolidge]

Can you turn that steel plate sideways and use the middle slot as a makeshift nozzle? You will have to block of the other slots and any other openings.

[Bender]

Can you turn that steel plate sideways and use the middle slot as a makeshift nozzle? You will have to block of the other slots and any other openings.

Unfortunately the plate isn't exactly square, so no, I can't reorient it. I did a redesign of the nozzle this am. Just fired it back up and crossing my fingers now. I cut out the cross bars that ran sideways and installed 5/8" steel in place with about a 5/8" slot roughly 4" long running vertically. Would have liked to have run a 1/2" x 6" slot, but the space wasn't long enough to allow, so I made it the max it allowed, 4" and opened the slot up a little to 5/8". I also lightly welded the previous cut out bar pieces on the underside of the newly welded in plate. My thinking there is that the more heat that the steel can hold, the better the chance of burning the gasses. And they were just lying there...

Here are the pics of the redesign.

[hondaracer2oo4]

Fingers crossed!

[coolidge]

How many holes on those outside rails? Looks like some might be plugged.

[Bender]

How many holes on those outside rails? Looks like some might be plugged.

5 holes on each side. I make sure they're open with each morning fill. Poor spot for air delivery... Of course this particular unit was a prototype and that design was scrapped in the production models. I believe they made a channel that runs up the back of the firebox and delivers the air much higher up. It may be a while before I get around to making *that* modification, but that could be at least a partial cause of the poor secondary combustion. I expect that air delivered above the fire would persuade the smoke/wood gasses to be pushed down through the nozzle better than having it delivered much lower.  Just curious, where is the primary air delivered on the G200?

I did a lot of trial and error testing tonight. I was mostly burning split cedar again, which thanks to HondaRacer I now understand is way low on the list of quality woods, but I figured if I tested with crap wood, things would only improve with the good stuff. With the primary air discs set about 1/4" open I played with the secondary and fan speed. Having the fan at full to half speed didn't make too much of a difference, but I did get slightly longer active burn times in the reaction chamber running the blower full bore. Next, I opened up the air box and set the primary discs open a lot farther, about an inch each, as the fire still seemed starved for air. Burn times in the reaction chamber increased 2X. Started playing around with the secondary air supply again and found that with it closed off as much as possible, burn times were significantly longer, around 4X.

I learned that tuning it by ear seemed to work the best. I open the main firebox and get a strong fire burning with good hot coals, then close it up, go around back and open the clean-out door for the vertical tubes and 1st set of horizontals. From there you can hear the jet engine sound of the secondary burn. By adjusting the secondary air supply and changing the fan speed I was able to tune it to where I thought it sounded best and lasted the longest.

I'm hoping someone that knows the Optimizer well can help me understand a couple of strange sounds that it makes sometimes. The first is a chuffing sound, kind of like an old locomotive, but faster. The other is a low whistling sound, like blowing over the top of a beer bottle if it had a 4" opening.

Thanks!

[slimjim]

I have been following the thread and have some ideas but they are going in the opposite direction of where you have been going, here is my advice.
First in the reaction chamber, the early models, before EPA approval there were two rows of brick standing vertically and running lengthwise, they were intended to create a channel that directed the gasses first forward toward the door then they passed to the outside and then back to the rear of the reaction chamber, it was much like the design of the Seqouyah Paradise E 3300 and 3400 models, it seemed like a good idea at the time but after running one of the early models ( not as early as yours ) for a short time, I had an idea that the channels were restricting air flow and impinging on the secondary burn flame, this idea actually comes from the oil and gas industry, flame impingement on any oil or gas burner always makes for a dirty burn. I removed all the brick in the reaction chamber and then replaced what I needed by cutting some and laying them flat, I think the chamber was about 14 inches wide so an 8 inch brick and then a cut 6 inch brick would run across the bottom, 2 inches high and 4 inch front to back, repeat this until you have covered the entire bottom of the reaction chamber. This opens up the chamber for far less impingement as well as making it far easier to clean behind the original passages.
Nozzle, I feel you are headed entirely in the wrong direction here, you may have noticed that most of my customers have tried and are now using a nozzle that Karl K builds, he and I discussed the design of that nozzle as the one that P&M made was constantly plugging up with ash, we opened it up to about 3/4 inch wide and the full length, I think that was about 10 inches long, then we gouged 6 channels, 3 on each side about 1/2 inch wide at a 45 degree angle to allow more air at a slower velocity through the nozzle, after replacing nozzles with my customers, the comments that I got were, wow that thing just came to life and it doesn't plug anymore, there are several of those folks on here and I'm pretty sure that they will chime in!
This of course is sort of mute for you as your design is completely different, my suggestion for you would be to get rid of the metal nozzle and lay another layer of brick in the bottom of your primary firebox, start from the center creating your own nozzle by simply leaving a space between the bricks about 3/4 inch wide and the length of a brick then work your way to the outside filling the entire base with 1 layer of 1 inch brick, Coolidge actually did this with his old unit and perhaps he may have a picture of it somewhere.
I will make a crude attempt to draw a picture of the retrofit but I'm not an artist so don't expect much.

[slimjim]

This is a rough idea of what I would do, the reaction chamber would be laid out the same basic way excluding the nozzle of course, a 4 1/2 inch angle grinder can be used with an inexpensive masonry blade to cut the brick, BE CAREFUL, the blade does not stop for flesh and bone, I learned from experience, hurts like hell and fingers don't work well when they are missing bone!

[hondaracer2oo4]

You said that you are getting a secondary burning for 4x longer now, how long is that? Have you tried quality hardwood yet?

[slimjim]

I don't know why it wouldn't post before but here is that drawing again

[coolidge]

You can see them here. http://www.youtube.com/watch?v=5WJns8SpQ88&list=FLYi_x_JqO5WMspfXizOU4Vg#

[Bender]

I have been following the thread and have some ideas but they are going in the opposite direction of where you have been going, here is my advice.
First in the reaction chamber, the early models, before EPA approval there were two rows of brick standing vertically and running lengthwise, they were intended to create a channel that directed the gasses first forward toward the door then they passed to the outside and then back to the rear of the reaction chamber, it was much like the design of the Seqouyah Paradise E 3300 and 3400 models, it seemed like a good idea at the time but after running one of the early models ( not as early as yours ) for a short time, I had an idea that the channels were restricting air flow and impinging on the secondary burn flame, this idea actually comes from the oil and gas industry, flame impingement on any oil or gas burner always makes for a dirty burn. I removed all the brick in the reaction chamber and then replaced what I needed by cutting some and laying them flat, I think the chamber was about 14 inches wide so an 8 inch brick and then a cut 6 inch brick would run across the bottom, 2 inches high and 4 inch front to back, repeat this until you have covered the entire bottom of the reaction chamber. This opens up the chamber for far less impingement as well as making it far easier to clean behind the original passages.
Nozzle, I feel you are headed entirely in the wrong direction here, you may have noticed that most of my customers have tried and are now using a nozzle that Karl K builds, he and I discussed the design of that nozzle as the one that P&M made was constantly plugging up with ash, we opened it up to about 3/4 inch wide and the full length, I think that was about 10 inches long, then we gouged 6 channels, 3 on each side about 1/2 inch wide at a 45 degree angle to allow more air at a slower velocity through the nozzle, after replacing nozzles with my customers, the comments that I got were, wow that thing just came to life and it doesn't plug anymore, there are several of those folks on here and I'm pretty sure that they will chime in!
This of course is sort of mute for you as your design is completely different, my suggestion for you would be to get rid of the metal nozzle and lay another layer of brick in the bottom of your primary firebox, start from the center creating your own nozzle by simply leaving a space between the bricks about 3/4 inch wide and the length of a brick then work your way to the outside filling the entire base with 1 layer of 1 inch brick, Coolidge actually did this with his old unit and perhaps he may have a picture of it somewhere.
I will make a crude attempt to draw a picture of the retrofit but I'm not an artist so don't expect much.

Hi Jim,
Funny... I did exactly what you described before this burning season. Took a 9" angle grinder with a masonry cutting wheel and sliced off the "C" channel, leaving the firebrick flat. WAY easier to clean now! Whether or not it helped it breathe better, I can't say yet.

I messed with tuning it and thought I had it dialed in last night around midnight. Got up this morning to find it at 133 degrees. (palm, forehead - forehead, palm) Turns out it does prefer a reasonable air flow in the secondary tube. It's gaining temp this morning at about 3-4 degrees per hour. No flame in the secondary, just a chuffing sound about every second, but not a ton of smoke in the firebox either, so I think it's burning the wood gasses, but more so in the main firebox than where it should be.

I've verified all air passages are open, but to my way of thinking, it's still acting as if there's some kind of blockage. Reading your explanation of your and Karl's nozzle design make more sense than ever now. I looked on the forum for a picture of one, as I read a lot of posts saying how well they work, but couldn't seem to find one. Sounds like I did go the wrong way in making the nozzle more restrictive, when what I should've done was to open it up more. I like the fire brick nozzle replacement idea! That should be fairly easy.

Thanks very much for the advice! There might be hope for this old beast yet.

[Bender]

You said that you are getting a secondary burning for 4x longer now, how long is that? Have you tried quality hardwood yet?

My record last night for secondary burn was around 10 minutes, but again that wasn't with quality wood. Today I'll feed it the good stuff. I'm sure that will help.

[Bender]

I don't know why it wouldn't post before but here is that drawing again

I always wondered why there wasn't any firebrick in the bottom of the firebox of this stove. I will pick the brick up and get started on that in a day or two.

Again, muchas gracias!

[Bender]

You can see them here. http://www.youtube.com/watch?v=5WJns8SpQ88&list=FLYi_x_JqO5WMspfXizOU4Vg#

Nice... I waaaaant that!   Do you have any pictures of the nozzle from the top side or out of the stove?

I noticed some other differences too. Looks like yours has firebrick standing vertically on the outside edges of the reaction chamber. Is that right?  Also looks like there's a raised firebrick directly under the nozzle. Is that fixed or movable?

Thanks!