I tried posting a picture, apparently my files are to large. on top of my combustion chamber (20 lb lp tank) I have a half inch hole where I dump my fuel and ignite the vapor. Infront of the tank is a 6ft steel tube 1/4" wall 3"od. On that tube I have rtwo 1/8" holes that had a bbq igniter that didn...

I recently built a spud/tennis ball cannon out of steel pipe and a propane tank, and after a few failedattempts to fire it with propane, I vented my combustion chamber put an Oz of 87 octane in it, and with the hole open I lit it. Kablewy like a rocket. Worked twice in a row like this. The next day ...