my dad attempted to make one, just as a fun experimental project. from what hes told me, all it did was burn gas, make noise and shoot flames. i just asked him, and he said it probably would propel something but he didnt want to push it that far.
probably wont help you much, but thats all i got.
its still together on a cart in my grandmas barn though, so i guess if you want pictures of it, i could get some.