Matt,
   I don't have P-Port.  I thought about it briefly but then started to shy
   away from that idea when I heard that the idle is rough and unreliable
   and that it is much louder.  I would like to retain as smooth an idle as
   possible while keeping the noise level down.  Although I don't mind some
   brap-brap idling, I mainly don't want the engine to stumble and die when
   pulled back to idle.   Honestly, I still open to ideas here. Again these
   are my goals:  "I would like to produce a consistent 350 hp that
   is maintained to 18K ft. altitude, but still idles well and is
   not ridiculously loud. "  I want to accomplish this goal in the most
   reliable and least stressful way on the engine.  I'm open to
   suggestions.
   Thanks,
   Don

   I am willing to bet if you idle an engine with a 2.85:1 gear
   box at an engine RPM of 700 and a prop RPM of 246 the prop will act
   like a giant drag brake and your approach angle will approach 90
   degrees :) I am only half kidding.

   Those that are flying, what engine RPM do you use on approach?

   Paul Lamar



I was planning on more like 1200 rpm idle (prop at ~420 rpm), but I do
get your point about thinking in terms of prop rpm rather than engine
rpm.  My plane is currently flying with a Lycoming IO-360.  On final,
I'm usually around 1400-1500 RPM and 85 kts.  Over the fence at 75kts
and touchdown at 65-70 kts.   It would really suck if I pulled the
throttle all the way back at touchdown and it died before I would rev
back up for the touch-n-go.  I probably never get below 1100 rpm while
in flight.  Taxi around 700-800 rpm.  That would be about 2000 rpm taxi
speed (2.85:1 PRSU), so I'm guessing I would need to idle around 1700
rpm to have the prop idle where it does now.  That seems to be close to
the 1800 rpm figure that I've heard is needed to get a P-Port to idle.
Probably would work out fine.

Don

I think a P-port at 2000 RPM is no more prone to die than
and AC engine at 700 RPM.

Paul Lamar

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