This in reguards to creating a vacuum in this turbine body. First this is not mine, how ever it will look much the same. Now here's the deal. Changing from ICDF to EDF on this Dynamax fan (body only here). You can see the insert for the motor in photo. When the rotor is arrached the clearence between turbine body and hub of the rotor is only about 2mm. ( Hub covers entire front of turbine body) First, even though the center of adaptor has holes for cooling, will that 2mm clearence be enough to get a vacuum going? Or would drilling, say 4 holes, either straight or at a angle, behind the adaptor ring help in creating some type of vacuum? Keeping in mind that the rotor will be spinning at up to 27.000 RPM's. Thanks for your help