In a pulse jet engine, combustion is intermittent or pulsing rather than continuous.LPG is pumped into the chamber, where combustion is initiated by a spark plug (only necessary to start it, then it is self-sustained). A series of spring-steel shutter-type petal valves are located ahead of the combustion section. Air is admitted through the valves, and combustion is initiated, which increases the pressure, closing the valves to prevent back-flow through the inlet. The hot gases are expelled through the rear nozzle, producing thrust and lowering the pressure to the point that the valves may open and admit fresh air. Then the cycle is repeated. The repeated opening and closing of the air valves makes an almost deafeningly audible "buzzing" sound

Some 3D generated graphic representations:

- The full setup. Note: the Oxygen canister is just there for looks, it is not used

- Close-up of the rear of the chamber. The end cap piece that connects to the chamber which the LPG supply line hooks into is a solid machined piece of metal. The cylinders around the cap are the ports for the air intake, and the concentric fins are for heat dissipation.

- A better view of the end cap. Note the air ports, of which a petal valve made from spring-steel is connected them on the inside of the chamber to control airflow.

- This is the petal valve which is on the inside of the chamber, connected to the end cap via a screw. It is thin metal, so it moves easy when force is acted on it, but it maintains its shape. They are dispensable and have to be replaced every so often, due to the high temperatures and forces acted upon it. Each petal flaps around 40 times a second.