Pineywoods, Thanks for the tips. As far as wood size, I've got a variety from standard cord wood to smaller pieces. Told my supplier that I was willing to take the stuff that might be too small for his firewood customers.
I did catch a video from Ben Lang showing how he starts his smoker. It was informative and I used some of his tips. The best tip was to get a good fire going, take the temp above what you want and then slowly feather the vents closed until the fire damps to the point that you have steady heat. That worked well for having good smoke at my last cook.
I also read a tip about closing the grease drain valve. I tried that and I tried changing the tongue level. Neither seemed to have any effect on the temperature spread from front to back. Here's a graph. (I know I didn't wait very long between making changes, but being there live, you can see changes pretty quickly on the stoker temp probes) Here's the stoker log data:
The red line on top is the pit temp measured at the stock thermometer location (top of smoke chamber).
The other three are measured at the lower grate level.
Blue is right of pit
Brown is middle
Green is left.
Note that the temps remained pretty much 100 degrees apart right to left regardless of what I was trying. I went from the tongue at its lowest point to about 20 turns above level on the jack (the toungue was pointing up at a very significant angle)
Note that at 8:00am, I started choking the fire back to be able to put the meat in. When I didn that, the right temp approached to within 50 degrees of the left temp. That's the closest it ever got. This tells me that when the fire is really cranking, the flames and likely infrared radiant heat are hitting the baffle plate directly from the fire. When I choked the fire back, the flames and IR dropped and the right side cooled.
Some things I want to try.
1st (and likely most important) it seems there's a bad weld on the right side. I think I see smoke coming from right to left at the right side (firebox end) of the smoke chamber when I first start the smoker. Obviously, that's going to need to be fixed as hot gases right from the fire will keep that end of the smoker at a higher temp.
2nd, If rewelding the right side plate doesn't help, I'm considering putting a baffle in the firebox to block heat/infrared energy from the baffle plate on the right side of the smoker. I might make something out of firebrick to reflect heat back into the fire and possibly get a more complete burn and less 'bad' smoke.
3rd. I want to try adding a baffle to the left side of the plate that extends down into the lower chamber. My idea is that it will help back up the heat and smoke under the plate and help raise the right side temperature.
4th, Modify the stack. I want to raise the stack about 60 inches for two reasons, 1, better draft and 2, get the smoke above my canopy so it doesn't irritate me or any neighbors I might have at an event. I'm also considering extending the stack downward into the chamber to cause it to draw heat from the grate level and possibly force the heat to even out in the chamber.
Any thoughts on my ideas?