Motorjets or "forced air ramjets" are not an efficent engine. They consume tons of fuel for the amount of thrust they produce.. but they're easily constructed at home out of minimal materials and they make some wicked flame shows and sounds.
anything can make a forced air ramjet... a small household fan and some heat ducting or stove pipe ducting with a nozzle at the end.. put some sort of fuel and ignition source into the middle section of the pipe and wham.. you've got a (primitave) jet engine.....
This larger device i have designed here would be used to power a gokart or some sort of vehicle..(it would probably consume a s#*t load of fuel while doing so and it would definately annoy the neighbors (this could be an advantage or disadvantage.. depending on how you look at it)
