Mailing List flyrotary@lancaironline.net Message #51710
From: Bryan Winberry <bryanwinberry@bellsouth.net>
Subject: RE: [FlyRotary] P-port Project Update
Date: Sat, 17 Jul 2010 15:11:17 -0400
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

Congrats Mark,

Encouraging  results for those of us pondering the PP.

BW

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mark Steitle
Sent: Saturday, July 17, 2010 9:05 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] P-port Project Update

 

A Flight Report to Spur a little discussion...

 

For those that haven't been following my project's progress (or lack thereof), I replaced my side-port 20B with a p-ported 20b in January of this year.  And have been fighting "issues" ever since.  The main problem was a persistent misfire at various rpm.  That appears to have been solved with a new CAS bracket and setting the gap to .025".  The rest seems to be tuning related.  I have finally managed to get it to run smoothly through the rpm range needed for safe flight.  

 

So, after a thorough pre-flight, I flew my p-port 3-rotor on Friday.  OAT was about 90*F, but coolant stayed below 200 during climb and oil temps were 185*F max, 165-170 in cruise.  The p-port engine ran great, except for a little mis-firing around 5700 rpm, which was corrected in flight with auto-tune.  Pre-takeoff run-up gave a brief excursion to 6900 rpm.  Takeoff run was 6500, running very well, but limited by prop setting.  It started to lightly misfire when I dialed the prop back for cruise-climb, so I dialed it back up to 2000 (prop) and it ran smooth again.  Once at 3500 and leveled off, I entered auto-tune and brought the rpm down to the 5700 range and let the EM-2 tune the EC-2, map addresses 90 - 92.  Afterwards, it ran great throughout the rpm range.  (I had "auto-tuned" much of the upper map range on the previous flight.)  

 

At 3500 - 4500 MSL, the EFIS was indicating 172-174 TAS at 1800 rpm prop setting, and 201-203 mph per the EM-2.  This is consistent with a previous test run I had recently done and represents a 12-14 knot improvement over the side-port motor.  The cool thing is that these speeds are in "economy cruise" mode.  EM-2 was indicating 12.1 gph, but has not been calibrated since switching to the larger 60 lb./hr injectors.  Engine was just purring along at 5500 rpm.  There should be a bit more speed on the table as I realized after the flight that I had never closed the cowl flap.  Oh well, I guess I'll just have to go fly again real soon to see how she performs with the cowl flap closed.

 

Later on, I plan to run it a bit harder, around 6500 rpm, and see how she performs.  I could hit VNE with the old motor if I ran it up to 6700-6800.   But since the vast majority of my flights are in the 5200 - 5500 rpm range the 12-14 kt improvement is very good to see.  

 

Mark

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