Here is my latest project completed. I had this old leaf blower motor and some pipe fittings and decided to bodge together an air/steam engine. I had an old broken socket ratchet that I though would make a good cam arm and a 2-1/2 pound dumbbell weight that was roughly cast.
Here is a test of the engine starting around 20 psi and increased to 60 psi then back down to about 15 psi. The flywheel needs to be balanced as it started to pick up a vibration around 60 psi. Otherwise it runs fairly well.