Back to Previous Page

Home Page

Valley Engineering Page
Valley Engineering

Culver Props Page
Culver Props

Pitch selection reference guide

View Entire Guide   or use our Pitch Calculator below:

Prop Pitch Calculator

Engine RPM engine RPM at cruise
Cruise Airspeed (MPH) anticipated cruise airspeed
Reduction Ratio (optional) :1 1.3 or 1.6 or 2.58 etc. (blank for none)
Prop Length (optional) in inches

Prop RPM
Recommended Prop Pitch (assumes no "slip")
Tip Speed (Ft/Sec) (if prop length given)
Tip Speed Mach % (if prop length given)
  • Recommended pitch is theroetical as it assumes no "slip".
  • For very high pitch props (70"-80") the calculated Tip Speed has been adjusted 5%-6% to approximate true helix Tip Speed.  Otherwise circular Tip Speed is shown.
  • Ideal Tip Speed varies depending on the H.P. per square ft of the prop disc.
  • The efficiency of a propeller is reduced as the tip speed approaches the speed of sound.  Beyond 80% of the speed of sound, further increases in RPM has little affect on thrust.  Thus, it is important to keep tip speeds below 75%-80% of Mach.