I plotted the max thrust for 300 HP on a Hartzel chart from
Modern Prop & Duct Design by M. Hollmann
This is what it looks like.
The prop is a three blade intended for a Cessna 210 and weighs 90 pounds!!!!
It is 78 inches in diameter at 2700 RPM.

Hartzel part number is HC-C3YK-1RF769X1

Twist is 33.8 degrees at r/R of .2 and 9.5 degrees at r/R 0.9 out near the tip.
It is not a Clark Y airfoil. Supposedly it is something like an Eppler but it
sure don't look like an Eppler. I will scan it in shortly.

Paul Lamar
 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org