Another newbie from Portland... Thanks to all for this great thread. I've read through most of the posts, but may have missed some, and I don't see anyone who's tried the LBE with charcoal. So in a first attempt at this endeavor, I've left my 22" Weber kettle as a charcoal fired grill but otherwise modified per the accumulated recommendations here.
So I started with a 22" inch old, hand-me-down kettle, lined with HD foil, and decided to go with a 20" aluminum pizza pan ($10, amazon) as the top reflector. Drilled a 4" bolt through the lid and hung the pan, and lined the lid with foil. The pan fits snugly - see pics. Then cut a 8" x 2" vent in the lid with a Dremel - best use of this tool ever. For the supporting grate, I took the standard cook grate and cut about 5" off of one side and flipped it upside down. On top, I have a layer of "gas grill blocks" to diffuse and even out the heat (Gas Grill Company, $20, True Value). Then I have a Old Stone Oven pizza stone in a shape I've never seen before: 20.5" x 15.5", with one edge squared off to fit a 22" inch kettle with the hinged grate ($55, amazon). Unfortunately, my grill didn't have the hinged grate, so I used the Dremel to cut off 5" of the grate to provide access for adding more charcoal (unnecessarily, see below).
I wanted to get the stone temp up to 700F, and I wasn't sure how much lump hardwood charcoal to use, so I probably overdid it with 2 thick layers of blazing hot coals. At 30 minutes, the stone was at 550 and the aluminum pan was about the same. So far so good. Got the pizza's ready, using the Lehmann recipe, and by the time I slid the first one from the peel the stone was at 850+ and the pan was 750. Ack! Not unexpectedly, the bottom crust was toasted as you'll see, and the top was just done. For the second pie, I shut all the bottom vents and took the lid off to drop the temp. Couldn't get it below 800, so cooked it and got about the same results. Two hours later the stone was still at 850 with all the vents closed. Needless to say, lump charcoal will get the stone as hot as propane.
So, I need to reduce the stone temp significantly at the time of baking. The options I see are to start cooking much earlier in the rising temperature curve, reduce the amount of coals, raise the stone higher, or lower the level of the top pan. Any other thoughts?