Question about temp control

[joshp]

I've got a okie joe longhorn which have a few mods, I've raised the grate in the fire box 3" and extended the exhaust inside the smoker and added a 90 bend and brought it down to grate level. I've also added 2 thermometers to the lid which are at grate level (cheap thermometers but passed the boiling water test) so my question is I smoked an 11lb pork shoulder Saturday and I could not get the grate level temp above 250 which is ok IMO because I like to keep it around 225 250 anyway but I had the air intake wide open and the exhaust wide open. It still would not heat up passed 250 @ grate level. Any ideas ?

 

[bmaddox]

What are you using for fuel? Charcoal with wood chunks or all wood? 

The short answer is to add more fuel to your fire. 

 

[daveomak]

Is the Longhorn lid "air tight" ... You may be getting leakage and false readings on the therms... Check the exhaust temperature to see what temp is inside the smoker...

 

[joshp]

Bmaddox I used hickory for half the time and used lump coal for the rest of the time but it seemed as if it didn't matter how much I put in it wouldn't go above 250

 

[joshp]

Dave the lid is not air tight which is something I've been needing to take care of thanks for the pointers guys

 

[joshp]

There is a thermometer in the top of the lid that came with the smoker and it reads a little high (going off of water boil test) and it reads about 300 when the two at grate level read 225 250, my theory is the hole that the heat passes through is so big the heat hits the top of the smoker and makes its way out the exhaust, what do you guys think ?

 

[crankybuzzard]

When you brought the exhaust down to grate level, that should help keep the heat from running straight out the pipe.  However, the heat may still be "rushing" so to speak.

Do you have a heat diverter plate and tuning plates installed?  That can help a lot.

For the lid seal, my son used the sealing tape made for a big green egg lid.  It's pricey, but it's held up very well and sealed the lid on his pretty good.

 

[joshp]

No I don't have any diverter plates or a tuning plate installed, I thought about making one that runs the length of the cooking chamber with smaller holes close to the fire box and larger holes on the exhaust side I just don't want to kill the temp all together and ill be sealing it all up maybe next week

 

[crankybuzzard]

The diverter and tuning plates will help a lot.  I wish I had a picture here to show how we did it on my son's pit.

The plate you're talking about will work, but you'll need quite a few holes of different sizes, not just a few here and there.

Here is a link to a good explanation of how to install.  http://www.smokingmeatforums.com/t/236402/tuning-plates

 

[joe black]

The convection plate that you mentioned with the holes that get progressively larger is a good way to go. Be sure that the plate only extends about 2/3 of the way across the CC. I would also suggest that you start your fire with the lump and establish a good coal bed and then switch to splits. Be sure to always keep a good coal bed. Don't let your splits burn down before putting more on. Also, if you can, pre-heat the splits. Put them on top of the FB or somewhere that they can get warm. That way they will ignite quicker.

Good luck, Joe

 

[joshp]

Thanks a lot joe I might try another shoulder or maybe even a whole chicken in a few weeks as long as the temps stay fairly warm during the day

 

[joe black]

Be sure to let us know how it turns out.

 

[joshp]

Will do !