SMOKE STACK BASICS

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But what I'm still confused about is where the percentage numbers come from.... percentage of CC .. you say you like to use 0.02... then you say Dave likes to use 0.022 .. you have all kinds of different percentage numbers in the chart... (grabs head with both hands on ears.. shaking back and forth... "I'M SOOOO CONFUSED" ) ,,, So your saying I can use any number I want .507 percent of cook chamber ... So confused I don't even know what I'm talking about now....
Sorry, don't mean to confuse anyone.   All those different numbers were for examples just showing the different stack lengths 

I like using the 0.020  for stack volume

This was based on a cook chamber I made up for the post just an example 

To Correctly figure the cu. in. on a stack for a different or your smoker we need the dimensions or the cu. in. of that or your cook chamber.

Gary
 
This is all good stuff. So if I catch the drift here with my smoker build that has a 6" stack I'll just have to watch my exhaust damper to to regulate flow and my inlet dampers for heat adjustment. If I have that correct. By the way mine is 6" pipe for the exhaust because it was totally free. [emoji]128077[/emoji]
 
Inkjunkie, in response to your remark. Please tell me how its any different to just tell you what size pipe you should use rather than using a fancy formula? Its all still based on experience of what usually works and what has not. One may "feel" more scientific to you, but its not.
Because I am kind of mechanical minded...and like to understand things. Please don't take offense to anything I have said....nor try to understand me...suffer from several mental ailments and am wired a bit different.

Another reason why I feel the way I do...I have been given so much wrong info from self proclaimed "gurus" over the years I have a difficult time believing folks anymore. If you provide the reasoning/data to back up what you are saying...
And generally speaking there is more than one way to skin a cat...
 
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Inkjunkie, in response to your remark. Please tell me how its any different to just tell you what size pipe you should use rather than using a fancy formula? Its all still based on experience of what usually works and what has not. One may "feel" more scientific to you, but its not.
Now, the true answer, from my perspective. No offense meant to anyone here. I don't get much feedback on the bulk of my questions on here anymore. If I am really in desperate need of input on something I generally look elsewhere. I don't like waiting, and often not receiving, answers to my questions. If I have a "fancy formula" at least I have something to go by...

To sorta prove my point....have you ever replied to any of my threads?
 
But what I'm still confused about is where the percentage numbers come from.... percentage of CC .. you say you like to use 0.02... then you say Dave likes to use 0.022 .. you have all kinds of different percentage numbers in the chart... (grabs head with both hands on ears.. shaking back and forth... "I'M SOOOO CONFUSED" ) ,,, So your saying I can use any number I want .507 percent of cook chamber ... So confused I don't even know what I'm talking about now....


Jack, morning.... ALL the numbers on the tutorial I assembled came from ACTUAL smoker builds.... Alien put together the original calculator from ACTUAL smoker builds, we, on this forum, adjusted it to perform better using actual smokers and tweaked the calculations... The 0.022 exhaust number came from actual smokers that had less than 5 degrees difference across the cooking grate... All of the numbers in the tutorial I put together, along with the help of MANY members, are real.... verified... used in actual practice...
 
Just wondering...one of the ways to figure out the collector length on a race car header is to use an infrared thermometer. Where the temperature drops off is usually a good starting point, or so I have read. Can't help but wonder if this is true with a chimney. When I get a chance I am going to mess around with my infrared thermometer. Would like more in depth with my explanation but have to get moving....Sorry for the hijack...



INK, morning..... the different temperatures on an exhaust collector are from the "exhaust pulses" generated from the pistons.....

We used the color variation on exhaust pipes, on the dragster I pit crewed on in the 60's, to determine the lengths of the exhaust tubes... You could visually see the dark bands vs. the dull red pulse rings..... The lengths of the tubes were adjusted to "scavenge" exhaust and eliminate back pressure... The same theory is used in the collector on a 2 cycle engine... scavenge exhaust to improve performance.... I don't see how that theory would work on a smoker, but then I have never looked at it...
 
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ok.. so lets see what you come up with for my 120 gallon tank... (24 x 61.5)... I have a 5" pipe and using a plenum...
24 v 61.5 in. cook chamber =  27,882 cu. in

using  0.020 for stack vol.   would be 556.4 cu.in

using 5in pipe  stack would be  28.34

Hope that helps
 
Actual smoker builds ----  Like I said at the beginning of this post we build one or two smokers a year, so I to have a pretty good grasp on what works.

The chart with all the numbers, and percentages were FOR EXAMPLE ONLY, which I think most everyone got. and understands, I also said  "I would not attempt to tell anyone what is correct or not correct, just what works for me and some good basic information, to help folks understand how and why the stack works."

Lots of builders have their own formulas for what work for them, If it works, you are happy Hey go with it.

For members who read and look at SMF on a regular basis know I smoke all the time, post lots of threads and how too's  I also said I can take my RF from 100º  UP in 10º increments  so I am thinking It works pretty well.

I am always open to new or better ideas to keep improving and making smokers better,

For those of you that are still confused like Dave, please PM me and I will try to explain further

Gary
 
Here is an idea ??    Lets move on to productive things,   I  am done arguing with sophomoric's    Just start your own thread !!!

Gary
 
Yes Inkjunkie, i have replied to your threads.
Strange...I don't see them. This solidifies my point, at least in my twisted brain. Why should I "trust" what you are saying when well...not going to accuse ANYONE of anything.

Here is an idea ??    Lets move on to productive things,   I  am done arguing with sophomoric's    Just start your own thread !!!

Gary
Will be copying/pasting Garys info and moving on.
Hope everyone has an enjoyable day...
 
I think its a good thread. My only argument is the formulas dont give a minimum or maximum diameter and just feel giving a recomended diameter to volume would eliminate confusion assuming length has very little effect ( with in reason)
 
Personally I never use anything less than 4"    on 250 gal smokers 6" looks and works great,  I've seen a few 500 gal. and 1000 gal smokers that were running 8"

I would agree with you that 4, 5, &6 in would be my choice for the size builds we do  mainly 4 to 5

Gary
 
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