My experience with Sterba props is that he "over-rates" the pitch number - he labels it a pitch that is higher than most other props with similar performance at a given RPM would have. So that 76" pitch Sensenich might be labeled a 78 or 80 if Sterba were to make it. Ed says that's not so, so it's just my observation, not a policy. Mark Langford
+++++++++++++++++++++++++++++++++++++++++++++++++++++++ For comparison, I ran a 62D x 66P prop on the O-200 on my KR. . -Jeff Scott ++++++++++++++++++++++++++++++++++++++++++++++ My Sterba prop is stamped as a 60X68, race profile. It was all my tired stock 0-200 could do to get 2300 rpm static. I sent it back to Ed to re-pitch to 64P. Couldn't tell any difference when I got it back. Maybe he just polished it and returned. Whatever it is in actuality it's probably just right for my KR as I get 2750 to 2800 rpm at all out cruse. I flew it full throttle for may hours until I decided to save some RPM for a later flight. I now cruse 2450 to 2500 rpm and indicate 153 mph at altitude on a reasonable day. My 0-200 had 1800 hours since factory overhaul when I got it and uses standard compression. I put another 600 or so hours on the engine before breaking it open to check condition of the lower end. Everything was in perfect condition so I re-assembled it with new bearings and seals and have put another 200 or so hours on it since then. AS always, YRMV........ Larry Flesner P.S The math would indicate that's pretty close. 2,450 rpm X 68" X 60 minutes = 9,996,000 inches per hour / 12 inches per foot / 5,280 feet per mile = 157.7 mile per hour. While I'm at it I'll toss out a rule of thumb on fuel burn for most of our engines. 1/2 pound of fuel per horsepower per hour . My 100 hp 0-200 running 65% power = 65 hp X .5 = 32.5 pounds / 6 pounds per gallon = 5.41 gallon per hour. With modest leaning that's dead on. -- KRnet mailing list KRnet@list.krnet.org https://list.krnet.org/mailman/listinfo/krnet
