One piston air engine(a mouth-blowing engine)

Hi everyone, let me start by saying that I try not to copy or even model myself after other air engine models. I tried to make what I created as best as possible. I got the idea from the Lgo vacuum engines I built a few years ago. This is my first model of this kind, and I definitely learned a lot creating it. There will be more models. I definitely want engines like: Boxer, V2 (configurable), inline, and probably many more.
If there's anything wrong with the printout or anything else, I'd be grateful if you could point it out in the comments.
I'd love to hear your suggestions for what engines and configurations I could create. Thanks in advance :)

Support needed 30-90°

(Please lubricate the pistons and whatever you want with oil before assembly)