X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.101] (HELO ms-smtp-02-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 5.0c2) with ESMTP id 711415 for flyrotary@lancaironline.net; Sun, 04 Sep 2005 23:26:47 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.101; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-065-188-083-049.carolina.res.rr.com [65.188.83.49]) by ms-smtp-02-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j853Q0l9007428 for ; Sun, 4 Sep 2005 23:26:02 -0400 (EDT) Message-ID: <000701c5b1c9$478f1770$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Another great flying day = another day of troubleshooting Date: Sun, 4 Sep 2005 23:24:09 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0004_01C5B1A7.C0278F40" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0004_01C5B1A7.C0278F40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Dave, Thanks for the reports, I don't feel so lonesome {:>).=20 Regarding SAG - my analysis is that susceptibility to SAG is = proportional to combustion chamber pressure at ignition and the = condition of the plugs. The more pressure - the harder it is for the = spark to jump the gap, so if your plugs are getting coated with = lead/carbon, I would expect to see more SAG with More manifold pressure. = Tracy and I have found the same thing (unturboed). At high power = setting (higher manifold pressure) the problem becomes more aggravated. = Reducing throttle setting helped - but, replacing (perhaps cleaning the = spark plug center ceramic cone) is the cure. I must have a fortune in = little-used spark plugs setting around waiting for me to have nothing = else to do but clean spark plugs {:>). I only use STEEL for my alternator arm - too much vibration there for = aluminum (my opinion of course, but having had aluminum brake line fail = - I'm a little leery of the stuff {:>)). Yes, they do call this experimental for a good reason - never to the = point where there is nothing to do. =20 I had one EFI pump fail early on - and it did fail suddenly - it was on = the ground, but one moment it was pumping fuel and the next it was not. = Interestingly enough the motor continued to humm and appeared to be = turning - but no fuel got pumped. Wish I had taken it apart to find out = what had failed. Ed ----- Original Message -----=20 From: David Leonard=20 To: Rotary motors in aircraft=20 Sent: Sunday, September 04, 2005 10:53 PM Subject: [FlyRotary] Another great flying day =3D another day of = troubleshooting 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.=20 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. =20 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. =20 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....=20 --=20 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=20 http://members.aol.com/_ht_a/vp4skydoc/index.html ------=_NextPart_000_0004_01C5B1A7.C0278F40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Dave,
 
Thanks for the reports, I don't feel so lonesome = {:>). 
 
 Regarding SAG - my analysis is that = susceptibility=20 to SAG is proportional to combustion chamber pressure at ignition and = the=20 condition of the plugs.  The more pressure - the harder it is = for the=20 spark to jump the gap, so if your plugs are getting coated with = lead/carbon, I=20 would expect to see more SAG with More manifold pressure.  Tracy = and I have=20 found the same thing (unturboed).  At high power setting (higher = manifold=20 pressure) the problem becomes more aggravated.  Reducing throttle = setting=20 helped - but, replacing (perhaps cleaning the spark plug center ceramic = cone) is=20 the cure.  I must have a fortune in little-used spark plugs setting = around=20 waiting for me to have nothing else to do but clean spark plugs=20 {:>).
 
I only use STEEL for my alternator arm - too = much=20 vibration there for aluminum (my opinion of course, but having had = aluminum=20 brake line fail - I'm a little leery of the stuff {:>)).
 
Yes, they do call this experimental for a good=20 reason  - never to the point where there is nothing to do. =20
 
I had one EFI pump fail early on - and it did = fail=20 suddenly - it was on the ground, but one moment it was pumping fuel and = the next=20 it was not.  Interestingly enough the motor continued to humm and = appeared=20 to be turning - but no fuel got pumped.  Wish I had taken it = apart to=20 find out what had failed.
 
Ed
 
----- Original Message -----
From:=20 David=20 Leonard
Sent: Sunday, September 04, = 2005 10:53=20 PM
Subject: [FlyRotary] Another = great flying=20 day =3D another day of troubleshooting

After a great trip to Santa Paula I finally solved my "compressor = surge"=20 issue.  Turns out that it was SAG (Spark plug induced Attention = Getter)=20 all along.  Sigh..   Despite the fact that the plugs = were only=20 a handful of hours old, and they worked fine at MAPs in the N.A. = range. =20 I was convinced that my power drop issue was surge because it seemed = directly=20 related to pressure ratio...
 
I finally change out the spark plug and wala... no issue.  = Now i=20 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=20 two.
 
Went out to the plane yesterday ready for a flight but found a = puddle of=20 coolant underneath...  sigh...
 
turns out that my lower radiator cap went bad.  Easy = enough. =20 Return the next day and install a new one.  Give everything a = good once=20 over and discover a broken alternator tension arm!!!   Holy = S*(^=20 !!  Broken clean through but not displaced very far (hard to=20 notice).  From the looks of it, the thing has been broken for at = least 20=20 flight hours!   Hmmm.
 
So I went home and made a new one - same design until I can come = up with=20 better materials and/or design.  Looking at the old one there was = the end=20 of a hacksaw cut right where break occurred.  I should have been = more=20 careful grinding it out. 
 
So that is fixed for the time being and I went flying with a = friend in an=20 RV-8 with a 180h.p. and c/s prop.  Except for initial = acceleration on=20 ground roll, I could out perform him in climb and cruise even with my = f.p .=20 prop.   :-)  COOL!!!!
 
But then I found my next problem....
 
Return fuel flow started drooping.  Where I normally see 30+ = gph=20 returned to the tank, I was seeing about 20gph.  We landed for = lunch and=20 I searched for signs of a fuel leak - none.  Fuel flow seem = normal on the=20 ground, as did fuel usage for the flight.  hmmm. 
 
On the way home the problem recurred, and flow continued to=20 dwindle.  at 4gph I turned on the aux pump and solved the = problem. =20 Sure was nice to have 2 of them.
 
I always pictured these pumps failing all of a sudden, but this = one just=20 sort of faded.  Has anyone had experience with this?  I will = check=20 the wiring and fuel filter... and report back.  Only 150 hrs on = this=20 pump.... I hope the next one last longer....

-- =
Dave=20 Leonard (just ordered a replacement pump from Tracy - but he is going=20 away...  sigh)
Turbo Rotary RV-6 N4VY
http://memb= ers.aol.com/_ht_a/rotaryroster/index.html=20
http://members= .aol.com/_ht_a/vp4skydoc/index.html=20
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