OK, the forum-software is a bit odd, but I'll get used to it.
This engine runs with very low pressure. Well below 0.2 bar. It runs if you blow into the tube. Green as can be! I tried it with 2 bar, then one cylinder blew off.
Forgot to tighten one screw.
I never intended to build an engine to be used in an aeroplane, it is just for display and playing with it from time to time.
Here are some pictures of the various parts. Overall, 29 parts (including 3 screws and one c-clip):
I'll post the drawings later.
If you have questions, you have to ask them.
Nick