Gravity feed Build - help!

[bigjohnsbbqnv]

I need some help from the pit builders on here!

This past summer I finished building my gravity feed. The details of the Build and cooking fuel are as follows:

Built with 1” square tubing for framing and 18g sheet metals. All welded seams. The cabinet dimensions are 22” L x22” W x34” H. My firebox and feed Shute are 1/4”. Feed Shute dimension is 6”x6” with no taper. Firebox dimension is 6”x17”x 7.5” tall. My heat transfer tube is 4.5”x 6.5”. All panels are insulated with 1”mineral wool. I typically run a Bbq guru on it for temp control. I couldn’t be happier with the consistency of the temperature. The Air inlet is 1” diameter pipe (I am currently making the inlet air larger) Stack is 6”x3.5” with adjustable damper. I typically use kingsford blue bag. I also Add some fruit wood or hickory chunks to the ash pan.

I learned to cook on an offset and my first few smokers were offsets. I love the smell when they are burning, but mostly the flavor you get from them. After cooking on the gravity feed about 20 times, I have never liked the smell of the smoke or the flavor on the meat. It tastes like a campfire. But the fire seems to be burning clean-ish most of the time. I believe the flavor could be coming from the charcoal, but I also have a few theories that I am looking for some insight on:

1. My heat transfer tube hieght is too tall, and the charcoal fire is too big for the amount of air these run on and the size of cabinet.

2. The inlet/stack dimensions are off. (I am thinking the stack is fine, but the inlet is not big enough.)

3. Need to try lump (but i’d Like to figure out the design flaw, because I like the consistency of the briquettes.)

I will post some more pictures later today but here is the final product.

Gravity Feed Build

• bigjohnsbbqnv
• Nov 20, 2018

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Your help is much appreciated!

 

[seenred]

I'm certainly no expert on the thermal dynamics, air flow, etc. of smoker design and construction. There are calculator formulas for figuring the dimensions of fire box, stack size and length, etc. in offset pits, but I've never heard of such a calculator for gravity feeds. That being said, I'd guess you're on the right track - trying different types of charcoal, and trying tweaking your air flow as much as your setup will allow, until you find the 'sweet spot'.

By the way, sweet looking build!
Good luck!
Red

 

[bigjohnsbbqnv]

I'm certainly no expert on the thermal dynamics, air flow, etc. of smoker design and construction. There are calculator formulas for figuring the dimensions of fire box, stack size and length, etc. in offset pits, but I've never heard of such a calculator for gravity feeds. That being said, I'd guess you're on the right track - trying different types of charcoal, and trying tweaking your air flow as much as your setup will allow, until you find the 'sweet spot'.

By the way, sweet looking build!
Good luck!
Red

Thank you! Maybe once I figure it out I’ll create a thread with calculators in it.

 

[seenred]

Thank you! Maybe once I figure it out I’ll create a thread with calculators in it.

That'd be great...I cook on a gravity fed myself, and like them so much that I've considered trying to build one.

There is a site out there on the web that sells a set of gravity feed smoker plans, with all the dimensions (and everything else) already calculated, but they're kinda spendy - around $80 for just the plans. If you got stuck, you might contact that guy...I've talked to him a couple times...good guy. He might be willing to give you some expert advice. Just Google Smoker Builder, and you'll find him - his name is Frank Cox. And he runs a forum for other smoker builders...you might join over there too and ask these same questions...might get more expert advice from others who've built pits similar to yours.

Red