It was something that i originally made as a small rock cannon. Then i found out that it that it could be made into a simple pulse jet.
Its easy to make and only cost $15.
Gatorade bottle with cap
Some flammable fluid. (I used hairspray and nitro gas for the rc cars)
2 screws about 1 inch or half (depends on the size of bottle)
Hot glue gun
Step 1: Step 1
First take the cap and drill 1/4 size hole.
Then drill 2 holes the side of the bottle. (Make the small enough that the screws can grip the plastic)
Take the screws and put them in the holes. Before tightening wrap wire from grill igniter around the screw.
Screw in the rest of the way and hot glue the top of the screws so that the wires wont fall off. Also if you have your hands on the screws you will get shocked.
Tape the igniter to the bottom of the bottle.