100 cubic-foot downdraft natural draft gas car kiln, built by Vince Pitelka in 1980. Note the softbrick burner port inserts, with a round port 1" larger in diameter than tip of burner. The port diameter expands towards the inside. These prevent any unnecessary secondary air from entering the kiln in the corners of the burner ports, and make it very easy to control oxidation and reduction.
Note the three white valve handles. On each side of the kiln, the three burners are attached via these valves and a copper tubing manifold to a single WCI gauge, which can be used to adjust any burner by opening the appropriate valve.
The object next to the center burner is a retractable preheat burner for candling bisque firings. The center burner lifts off its orifice pipe, and the preheat burner swings in front of burner port.