Hi Cas,
First off, I wanna thank you for all the information you have put on this website. Really appreciate it.
Now coming to the question, could you please give me a rough figure (or a precise one if you could) on the radial clearance - between rotor and housing - found in an oil-flooded and an oil-free compressor of lets say 100mm dia rotor size. I want to compare these clearance values in oil-flooded & oil free variants. These values of any compressor model/make will do.
 
Background: I am doing an academic research on how the presence (or absence) of oil changes the thermodynamics of compression which in turn requires different clearances which in turn changes the manufacturing costs of the two types.
Regards
Fahad.