Shroud Clearances?

[RSS]

Building shroud and wondering what clearance should be around fan? Also is it still old rule of thumb to have 2/3 in and 1/3 out of shroud? Thanks

[Lizardracing]

The idea is to prevent the air from spilling off the end of the blades so 1/2" is good with 1/2 in/out blade coverage is a good place to be. Any is better than none but try to make the curves as gentle as you can.