I saw this in the 2011 El Centro Air Show info For the more Technically Minded Photographer.
Aircraft: Pitts S2-B (Meteor)
Propeller speed: 2700 RPM
Number of Propeller Blades: 3
For photographers;
Time for the 3 blades to create a 360 degree prop arch: 0.0074 sec ( 1/135 sec)
(60 / RPM / number of blades =60/2700/3 = 0.0074)
Closest shutter speed 1/125 sec.