Originally Posted by fishguts
Yeah, I see a sump! I don't see any reed valves, just a piston valve in the inlet/outlet bore. Sure does look like it's just asking to be a steam engine. Guess I'll keep my eyes open for one of those ... you, know, for something in the future ...
The reed valves are labeled "plate" in that drawing. Check out the link for more photos of its guts.
If it had space for a camshaft I'd think of making one of these compressors into a four-stroke motor. I wonder if it would work as a two-stroke? You'd have to cut ports into the cylinders and add a cooling jacket, but it might work. Maybe I'll make a separate thread for this.