Jet Engine

Steel tube should be fine. Bearings all need to be before the combustion chamber. The compressor gets wider, a cone built up from washers. The blades are made of thin stainless steel sheets, cut and bent to the correct size. The angle of attack of the blades becomes more aggressive, so that the final stage is more of a centrifugal compressor than a turbine compressor. The fuel is injected and ignited right there, after which it expands and passes by the turbines.

I'd really like to try a basic build just to try the feasibility. If it works, I can try a few more revisions focusing on efficiency. I'd actually really like to use one of these to power a go-kart, not using the force of the gas, but using the rotational energy.

From the deeper research I've done, the challenge really seems to be compression. So a good prototype would be to just build the compressor and hook it up to a starter motor and see if I can get the necessary compression. Same research also suggests that flat blades and insufficient, an airfoil is necessary.