Photo provided by Donald Kurtz, local scale builder. He’s building a Beech 18 and needed two dummy radials. No engine kit was available in the correct scale. The metal parts are K&S aluminum and copper tubing. The brass you see on the plug wires is brass rod. Cylinders are hardwood dowel, heads and rocker boxes are balsa. Engine block is the top of a plastic drink bottle with a thin plywood washer to form the brush-less motor shaft exit. The entire engine comes apart just in case he needs to service a cylinder. The rocker box’s will not be visible when the cowling is installed and are simply there to hold the push-rod tubes. Great job Don!