Burn Tunnel to Heat Riser Ratio...

[pluton5]

pomys³ dobry
Zrób tak,¿eby by³a mo¿liwoœæ skrócenia poziomego tunelu w razie koniecznoœæ bo komin jest wysoki i dopalanie bêdzie dobre
podaj jakies wymiary

good idea
Do this to be possible to shorten the horizontal tunnel in case of necessity because the chimney is tall and burning will be good, I am writing because I've done similar, and after shortening the tunnel was better
please have any dimensions

[Deleted]

The physics says:
The feed chamber adds resistance to the stream too, not only the burn chamber.

Looking at your picture, the working ratio may not be as good as you seem to think.

[Dan (Upstate NY, USA)]

The dimensions are 12" x 48"

or 30.5 cm x 122 cm.

I am not sure this is a good ratio.

That is why I am asking about it.

Thanks for looking.

[Donkey]

The dimensions look workable to me. The rule is, the heat riser should be twice as tall as the burn tunnel is wide and (also) 3 times as tall as the feed box.
You have an odd "jog" in your feed, it looks constricted. Is that intentional?

[Dan (Upstate NY, USA)]

The old jog is 7"x7" and it opens to 7x9 at the top, I suppose I could cut the top brick to 7" to get rid of the jog.

[Donkey]

Do that.. You will have smoke-back issues if the opening of the feed is substantially larger than system size.
You can get away with a little bit of difference, but 7x9 compared with 7x7 is EXTREME.