The first step was to make a rotor mounting fixture to hold the rotors during machining. This was done out of a block of 6061 aluminum.
The rotor was then bolted down and ready to be machined.
The DMU 50 went to work machining out the turbo-specific lightening program.
Milling out these lightening pockets on each lobe of the rotor greatly reduces the overall weight and reciprocating mass of the rotor. Since these are cast iron rotors, removing even a little bit of material makes for a big difference in weight, which is very important for our high rpm use.
To finish off the machining, we side clearance the rotor by grinding down the side face of the rotor roughly 0.006” (depending on the original width of the rotor) while the center gear land was left untouched. Reducing the overall width of the rotor is crucial for a high-powered street or racing engine to prevent the rotor face from striking the side irons as the rotor wobbles and the block twists from heavy load.