Anyone have any insight on how viable this thing is? I've read mixed results about it. I'm starting a 250 gallon Moberg clone and am using this calculator as somewhat of a baseline on my firebox, etc. I'm going with a slightly oversized firebox by their calculations, which I don't think hurts me at all. It will of course have the insulated firebox as well. Here's a pic of my dimensions so far:

https://imgur.com/gallery/4yiueJg

I use it as a guideline and adjust the measurements as needed. Feldon's seems to make the fire boxes a little bigger than what is necessary though. What are you using for your smokestack?

It's very viable

8" pipe 90 coming out of chamber then reduced down to 6" pipe for the stack itself. Also thinking of using square tubing possibly, just because we do plan to build more of these to sell possibly and I'd like to have a little of my own flare to it. Also considering a toying with adding dampeners to the firebox door. Moberg is booked into 2021 for a reason, but frankly I think his firebox door being cracked as the dampener is cheesy. But he's also getting rich off bbq pits, so I know he must be something right.

I think that smokestack would work well. I have put dampers on fire boxes in the past but have started leaving them off on the last few pits after reading Franklin's book and taking notice of the big dogs of put building. It also seemed that most people were leaving the door cracked on their fire boxes even with a damper.

I may just have to stick with the Moberg design then.

Feldons is good. Not saying it is perfect, but your pit will draft and cook very well sticking to the calculations.

Yes they have you make to fire box huge. But once you get them hot they stay hot

I also use Feldon's as a guide, but as posted earlier their fire boxes tend to run a bit larger than necessary. I find that the other areas are really good though. You will have great success just going with their recommendations though. BTW I always use a damper on the firebox.

This looks like a fun project. I am by no means an expert but why would you want such a large fire box? The fire box is like a necessary evil that adds weight and not cooking space.

Not so much worried about the weight the pit will be mounted on a cart on golf carts rims and tires. As for the firebox size the size is pretty in line with what Feldons recommended. Too big of a firebox can't really hurt.

I went to Feldon's last week trying to figure out how to fix a pit that doesn't cook too well and hasn't been used much. It was never good at transferring the heat from the firebox to the cooking area.

The pit is 24" diameter pipe, with a 48" long cooking area and a 30" long firebox/direct cooking chamber. I've always thought the chimney needed work.

The current chimney is 3" pipe that is about 3' long, with a 90 degree elbow right after it comes off the end of the cooking area. A while back I had planned to have a second chimney added. I was sidetracked when some buddies went to do the work and next thing I knew, the chimney that was originally attached to the flat end of the 24" diameter cooking area of the pit was only relocated to the top of the end of the cooking chamber from the center of the end of the pit. They plugged the old chimney hole with the piece they cut out at the new location. I had intended for them to use the extra pipe I had provided to add an additional chimney instead of just relocating the one that was there.

When I got to Feldon's last week, it told me that the 3" chimney should be 8' long (confirming my belief of insufficient air flow). Since I want to be able to reach the top of the chimney to control the vent, I'm back to thinking about adding the second chimney. I have some 4" pipe that I thought I would put on where the existing 3" chimney was originally located before my buddies moved it. If I make the 4" chimney 34" long, then it should give the pit the Felton's recommended Chimney volume when added to the volume of the 3" chimney.

Any advice from yall as to what you would do in this circumstance?

When building an old school pit, do you normally put the chimney:
1) at the top of the pit;
2) on the end of the pit near the top;
3) at the end of the pit near the center of the pipe; or
4) somewhere else?

Thanks!

ETA: I know the existing firebox is nearly twice the size that Feldon's recommends.

I always put them on the end near grate level.

If used for smoking, you want the chimney at grate level...the goal, with a good draw, is for the smoke to flow across the meat, not above it.

That was the original version, but just built with too small of chimney pipe. Perhaps I'll just find some 6" pipe. Feldon's says two feet of it would be sufficient, and then I can just keep the other existing chimney closed.