Mr. William Schubert (later Lieutenant of the US Navy) founded the “Valveless Manufacturing Engine”, around 1930/32, as recorded in an entry of that date in the USNA, with registration number 3219-452.8.

-It was in 1944 when he offered his simplest engine under the name “Resojet”.

-Schubert carefully calculated the geometry of the intake tube so that the exhaust gases could not escape through it at the moment when the internal pressure of the engine was greater and until the "suction" effect that followed, produced by the "inertia" of the exhaust outlet.

“Schubert Resojet schematic”

“Schubert Resojet development”