Jet Powered Hovercraft

Chris and I decided we needed to build a propane powered jet engine using a turbo from a car. Given my previous successes with hovercrafts, of course we needed to step the game up.



Our combustion chamber takes air from the compressor, swirls it around with liquid propane, then burns it, creating a huge expansion of the inputs. The gases then pass out into the turbine section of the turbo, spinning the compressor faster, and so on. The brass nozzle you see is the propane connection. The sparkplug is to start the combustion, but the flame is self-sustaining once it's running.



We rigged the combustion chamber to the output of the shop vac, connected the spark coils, and let a little gas flow. Much to our surprise, a significant roar was produced! We were even more pleased when the roar continued after we switched off the sparkplug. Below, Eric inspects the turbo.



When we put it all together, the unit was spinning at upwards of 120 krpm, and blasting the rhododendrons around across the yard. We also used it for snow clearing.

While we still had it running (ie before it was scavenged for parts), two exciting things happened. Once, when we drilled out the propane fittings to get more gas through. This made the engine run at a higher compression of course. Right as Ken reached across the motor to poke a gauge, the cold air manifold from the compressor separated from the combustion chamber, and the resulting gas instantly melted all the hair off Ken's arm. However perhaps more amusing was the time the bearing's oil seal failed during a full-thrust run. 60psi hot, thin motor oil sprayed into the turbine housing and instantly turned to smoke. The sheer amount of black death coming out the back of that jet engine is an image I won't soon forget. epic.