Hi Fellow Owners,
I got a puzzle to solve here, and I’ve pretty much explored all the possibilities I could think of. Durig the post-annual flight with my Piper Service Center IA, he noticed the RPM reading during the VY climb on my 161 is very high. It was at the redline, sometimes even past it. This happened during the cruise climb, too. Since then, I’ve done static RPM test and cruise RPM test using the digital tachometer, both the digital and analog RPM readings match, and it's within the limit - within 2330-2430 RPM with the -60 prop.
Thinking it might be caused by the prop, my IA and I talked to the Propeller Shop that overhauled my 74DM6-0-60 recently to get some data, and the owner confirmed that the prop’s diameter was at 72 inches, rather than the standard 74 inches, at the time of the overhaul. She agrees that this could be the reason to cause the high RPM during the climb because “the shorter the propeller diameter the quicker it turns”.
I also submitted this case to my Savvy MX account manager, and he couldn’t think of any reasons based on all the tests we’ve done, either. He doesn’t want to unplug the prop for a new one unless we are 100% sure the prop causes the high RPM.
Has anyone experienced the same before? For now, I’ve been reducing the power to 2400/2500 during the climb but it doesn’t seem to be ideal in the long run
.
Thanks!
I got a puzzle to solve here, and I’ve pretty much explored all the possibilities I could think of. Durig the post-annual flight with my Piper Service Center IA, he noticed the RPM reading during the VY climb on my 161 is very high. It was at the redline, sometimes even past it. This happened during the cruise climb, too. Since then, I’ve done static RPM test and cruise RPM test using the digital tachometer, both the digital and analog RPM readings match, and it's within the limit - within 2330-2430 RPM with the -60 prop.
Thinking it might be caused by the prop, my IA and I talked to the Propeller Shop that overhauled my 74DM6-0-60 recently to get some data, and the owner confirmed that the prop’s diameter was at 72 inches, rather than the standard 74 inches, at the time of the overhaul. She agrees that this could be the reason to cause the high RPM during the climb because “the shorter the propeller diameter the quicker it turns”.
I also submitted this case to my Savvy MX account manager, and he couldn’t think of any reasons based on all the tests we’ve done, either. He doesn’t want to unplug the prop for a new one unless we are 100% sure the prop causes the high RPM.
Has anyone experienced the same before? For now, I’ve been reducing the power to 2400/2500 during the climb but it doesn’t seem to be ideal in the long run
. Thanks!
