The rotors are located by the oil scrapers and side seal spring pressure. They have a land area on each side that will support the rotor in the event of hard braking or an over heated oil situation that makes the rotor thicker or allows the gear to walk out of the rotor. Normally there would be about .005" gap over each land area, and nothing will touch the irons. The clearance will be increased for racing and the sides of the rotor near the apex seals will be reduced by about .010" to allow for the rotors to tip a bit when the crank bends from over-speeding the engine (above 9,000 RPM). Not required for aircraft use.

 

Excessive end play or no end play will not affect the rotors.

 

Lynn E. Hanover