Mailing List flyrotary@lancaironline.net Message #26326
From: David Leonard <wdleonard@gmail.com>
Subject: Another great flying day = another day of troubleshooting
Date: Sun, 4 Sep 2005 19:53:13 -0700
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
After a great trip to Santa Paula I finally solved my "compressor surge" issue.  Turns out that it was SAG (Spark plug induced Attention Getter) all along.  Sigh..   Despite the fact that the plugs were only a handful of hours old, and they worked fine at MAPs in the N.A. range.  I was convinced that my power drop issue was surge because it seemed directly related to pressure ratio...
 
I finally change out the spark plug and wala... no issue.  Now i sort of wish I didn't cut off the waste-gate flapper....  oh well.
 
But life with an auto conversion seems never without an issue or two.
 
Went out to the plane yesterday ready for a flight but found a puddle of coolant underneath...  sigh...
 
turns out that my lower radiator cap went bad.  Easy enough.  Return the next day and install a new one.  Give everything a good once over and discover a broken alternator tension arm!!!   Holy S*(^ !!  Broken clean through but not displaced very far (hard to notice).  From the looks of it, the thing has been broken for at least 20 flight hours!   Hmmm.
 
So I went home and made a new one - same design until I can come up with better materials and/or design.  Looking at the old one there was the end of a hacksaw cut right where break occurred.  I should have been more careful grinding it out. 
 
So that is fixed for the time being and I went flying with a friend in an RV-8 with a 180h.p. and c/s prop.  Except for initial acceleration on ground roll, I could out perform him in climb and cruise even with my f.p . prop.   :-)  COOL!!!!
 
But then I found my next problem....
 
Return fuel flow started drooping.  Where I normally see 30+ gph returned to the tank, I was seeing about 20gph.  We landed for lunch and I searched for signs of a fuel leak - none.  Fuel flow seem normal on the ground, as did fuel usage for the flight.  hmmm. 
 
On the way home the problem recurred, and flow continued to dwindle.  at 4gph I turned on the aux pump and solved the problem.  Sure was nice to have 2 of them.
 
I always pictured these pumps failing all of a sudden, but this one just sort of faded.  Has anyone had experience with this?  I will check the wiring and fuel filter... and report back.  Only 150 hrs on this pump.... I hope the next one last longer....

--
Dave Leonard (just ordered a replacement pump from Tracy - but he is going away...  sigh)
Turbo Rotary RV-6 N4VY
http://members.aol.com/_ht_a/rotaryroster/index.html
http://members.aol.com/_ht_a/vp4skydoc/index.html
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