B.Day

Need advise from those who know about 160's. I have a Ultra Sport 1000 with 160 pulling a 16x10- APC on the ground it turning about 8,000. I think this is too high for this size engine. Plus when I run it by me at in a flyby in a slight or shallow dive and the motor is unloaded it is making a funny tinny kind of sound sound. I don't know if it's coming from the prop or the engine. Runs really great and performance is great.
NO, not too lean making smoke, but I worry about overreving it and damaging the motor. Maybe I could run a bigger prop and get more performance from it. I talked to a friend who is running a 17X12 on his pattern plane. But his plane weighs less than my U.S. does. Mine comes in aobut 12+- . I wanted to try a 17X9 But APC does not make one. So I went wtih the 17X10, too much prop pulled rpm's down to 7,000, motor could not get up to good RPM performance was less. 160 pulled it quite well tho.
All that to say this. What is the optium RPM for this engine. I.E. what should I be shooting for?
Also I have another plane, C.G. Sukhoi, with O.S. 160 running a 16x10 Airscrew three blade and it's turning about 7800=+.
Bobby Day

maukaonyx

Bobby, I am running an 18x6W APC on the OS 160 in my Giles 202 that weighs right at 12 pounds. Flies fast, pulls vertical like crazy, yet slows for soft landings. Mine has a Slimline Pitts style muffler on it, no pump. Not sure of my RPMs, I just prop to fly as best as I can get each plane for my style. My son uses the same prop on his heavier GP Extra Soucy with equally good success. Jon

jhatton

I was flying an APC 15.75 3-blade repitched to 10 on my os 160 with my overweight pattern plane... made good power and good downline speed with the 3 blade. I have since converted the plane to electric but have 1 Lockhart repitched 3-blade prop remaining. A good vibration mount and tuned pipe also greatly benefit this engine.