This pulsejet engine was custom-built by Robert “Larry” DeCou in his spare time while working as a machinist in the sheet metal and welding shops at Rohr Aircraft in Riverside, CA. He started with a number of aluminum parts, but they were not able to withstand the heat of engine operation and were eventually replaced by 321 stainless steel parts. (The spark plug, for example, still has electrodes that are almost burned off.) The nozzle at the air intake was purchased from DynaJet and has interchangeable size tips. The engine is about 21-1/2″-long overall, and the exhaust tube has a 1-1/4″ outer diameter. The engine was run about 3 times.