New pit with wrong ratio's (?) i think

[bighoss450]

I need help.after reading so much in the last few weeks i stumbled across a thread on pit ratios.Mine are way off.I have only been able to fire this 2 times.First time Took 80 pounds of bge lump coal to get to 250 deg.and hold there for 6 hrs.that was lighting it with chimmeys before adding to box.and everthing wide open including fire box door.Not hot enough to season in my mind.
Second time I fired I filled my cooking chamber pans full of hot lump coals and put 4 chimneys of hot coals in fire box and it got to 400 deg.these were all checked with digital probes not the guess gauges.
Here is my pit dim.11" long by 31" round.fire box 30x24x24=17280,chimney dia.5"x68"=340,firebox fresh air intake area3x5=15,firebox to cooking chamber opening 4x14=56. If i looked at this right every area is way under sized.
My ? is if someone could check my numbers and let me know how much more air, chimney stack and openings i need to add. Thanks so much and sorry so long.
hoss

 

[richtee]

Hmmm... I have always figgered the intake has to be capable of a bit more than the stack, but stacks are usually left full bore open in all the pits I have used. I'd start with increasing the intake size, Perhaps to 40 Sq.". And chimney area..i'm confused by the 68"? I mean it's a 5 inch pipe, right? 5X3.14= 15.7

80 flippin' lbs? Yeesh! Got a pict of this monster? Seems WAY much charcoal...

 

[peculiarmike]

Sounds like your firebox is too large. It does not take a huge firebox to heat a large smoker. 16" x 16" x 24" will do nicely with a 1 1/2" opening all the way across the top into the smoker. The area of your exhaust should closely match the area of your intake. And you need some sort of grate to keep your charcoal, wood, whatever fuel you burn up off the floor of the firebox so air can get under it.
$.02

 

[bighoss450]

My chimney is 5" round by 68" tall from cooking grate up. I am using a grate in fire box 2" tall off bottom. Richtee would u increase the opening into pit or fresh air and how much would u open it up? Thank yall for responding to a newbie.
hoss

 

[richtee]

Intake air. And why so long an exhaust? That's nothing but a problem, restriction in flow... I'd not have more that 3 foot on it. Let it BREATHE.

 

[bighoss450]

Are you thinking I should extend my exhaust. that would be easiest if ya'll think that would help or would i need to go with 2 exhaust pipes. What volume of air intake should i go to? And do you think my 4x14 opening into the cooking chamber is ok? again thanks to anyone who wants to help.
hoss

 

[richtee]

No! Any length of pipe just increases air flow resistance. Cut it off to 2 foot. And increase intake a bit, so you can damper it to what you need, or "gun" it to get the fire going before the meat hits.

Again..do you have a pic of this pit????

 

[bighoss450]

I do not have a basket, I have a grate. Also I'm going to try a put some pics. on here in a few if i can fiqure it out. So it sounds like I need more air and a shorter stack on my exhaust. I can take the sawzall to it and get rid of 2 feet if thats what yall are thinking. again thanks
hoss

 

[bighoss450]

Here are some pics. of my rig. If you need any other shots let me know and i'll try to get them. As you can see in one photo of fire box it has peeled the 1200 deg. paint so it is getting very hot. I do not know if I would make the opening into the cooking area larger if that would help. Thanks again from a newbie.
hoss

 

[bighoss450]

It is built as a reverse flow lang type. I will go get a photo in a few . It has a smoke chamber the whole length to the back of tank as you can see I think in photo. Then my 3 charcoal pans sit on the rails to block off the smoke till it can come to the back of tank across the meat to ex. pipe. Im sorry you know all this I will go get a phto for ya. thanks again for your reply
hoss

 

[bighoss450]

Here are some more pics on the inside. Hope this will help to lead me in right direction. Again thanks for the responses.

 

[richtee]

I agree on the increase. And shorten that exhaust stack. Looks like someone build for show, not go, BUT It can be made a "goer"!

 

[bighoss450]

Ok I understand I need to increase my air intake. Are ya'll saying to also increase the diameter of exhaust and also shorten the stack. Do you think that small opening going into the cooking chamber from fire box is ok. thanks
hoss

 

[bighoss450]

Thanks Ken and Richtee and others. I Will open that up and see how that works. Any other recommendations will be much obliged. Happy Easter to all.
hoss

 

[neens]

I think they nailed it. The opening on the langs are very large I have a 60 which looks to be a little less than half the size of yours but the hole in the fire box is about 3 times the size. It looks as if it was cut to be as large is it can. You can see the baffle plate and the bottom of the cooking chamber. If you want some pics let me know I will throw them up.

Also I cant really see but does the plate welded all the way from back to front. it kooks to me like its not in thoes pics.

 

[smok'n steve]

Model 60 lang firebox opening. I think thats one of your problems! You also have to realize that your smoker is VERY long>

Good luck, Steve

 

[bighoss450]

Thanks to all who responded what a great group here. The plate is welded all the way frt to back. I took the torch out this am and opened er up.You wont beleive what I found in there. I reached in to get the metel out that I cut and lo and behold there lay a bottle jack. Gees wonder if he is missing a bottle jack.

Well it worked great!!!!! It was my first smoke. Did a fatty,ribs and 14 pounds of butt. Everthing tasted awesome don't know about butts not done stuck at 194. She held good all day in that 220 to 240 range.

I think i will need to remove her green lable since she ate 80 lbs of lump and lots of sticks of cheery and hickory. I have some pics but will wait for the butts to be done before post. Again thanks everybody.

hoss

 

[richtee]

LOL yer gonna miss that special hydraulic fluid flavor I bet... a freakin bottle jack? Heh!

Carry on, Smoker!