According to my calculation using the calculator here you need 110-111 square inches of throat opening. An opening 10"x 10" will get you 100 sq. inches. There are cals here to find the area of a quarter circle. You will need to make sure you get to that 110-111 number. Have the top of the fire box and the BP plate the same height and make the opening into the CC have a small lip on the bottom to catch any grease that may get under the plate and keep it out of the firebox.
I got a 4" stack diameter at 55 or so inches tall and two fire box openings of 2"x 10" for intakes.
I have not played with the other calculator for the quarter circles so mess with that a bit and see what shakes out.
edit...if your a hands on guy and not a math wiz tape two pieces of printer paper together end to end and grid them off with one inch squares. Hold that paper up to your 24" pipe end where you think you might want the BP to go and draw a line around the paper where the pipe meets it. Count up all the whole squares and then add together all the partial squares and see if you get to 111 sq. inches. It might take a few tries.
The range is 2-6 inches clearance between the BP and bottom rack. I prefer the 3-4 inches myself but anywhere in there will work. The closer to the BP the more radiant heat you'll get so it's possible to cook the bottom of your food before the top, too far away and you lose the benefit of the radiant heat.
Awesome thank you guys very much. Next question, is 24x24x24 a good size for that size of a cook chamber. I just want to make sure I get everything right.
That size FB is 127% of the recommended size, 115% is the max that you should go. If you go 24x24x20 that's 106% 24x24x21 is 111% 24x24x22 is 116% , the 106% FB calls for a 92 sq inch throat, the 111% Fb is 97 sq in the 116% Fb is 101 sq in throat.
Something I didn’t think about, if I use the top of my firebox plate as my BP I won’t be able to do 24x24x24. I’ll have to make some adjustments and go from there. Once I get those measurements I’ll have to get your guys opinions.
Haven’t got much done since the last post. Work got in the way of any progress. I was able to get the trailer ready. Any ideas on mounting the smoker to the trailer?
On my first trailer build I worked it the math for the height I wanted my main cooking grate, subtracted my trailer height and then I built the stand that it’s mounted on. Once my pit was completed I sat it on the trailer and moved it back and forward until I got the tongue weight that I wanted. Then I welded the crossmembers to my frame rails. I have come to find that the FB is usually really close to the axle if you don’t have any extras built on the front of your trailer.
Thanks guys. It was a boat trailer. It was not galvanized unfortunately. I had it sandblasted and a coat of primer put on it until all the fab work was done, then it will all be painted at once. Here’s a picture of it before anything was done.
I’m trying to figure out what size I need for a stack. I have a 6” pipe just not sure what length I need. Tried to use the calculator, doesn’t seem to be working for me. Can you guys help me out