X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 23 Mar 2009 12:59:54 -0400 Message-ID: X-Original-Return-Path: Received: from nskntmtas01p.mx.bigpond.com ([61.9.168.137] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTP id 3556062 for lml@lancaironline.net; Mon, 23 Mar 2009 05:24:29 -0400 Received-SPF: pass receiver=logan.com; client-ip=61.9.168.137; envelope-from=frederickmoreno@bigpond.com Received: from nskntotgx02p.mx.bigpond.com ([143.238.210.80]) by nskntmtas01p.mx.bigpond.com with ESMTP id <20090323092340.EIVV27976.nskntmtas01p.mx.bigpond.com@nskntotgx02p.mx.bigpond.com> for ; Mon, 23 Mar 2009 09:23:40 +0000 Received: from Razzle ([143.238.210.80]) by nskntotgx02p.mx.bigpond.com with ESMTP id <20090323092338.GTFI6515.nskntotgx02p.mx.bigpond.com@Razzle> for ; Mon, 23 Mar 2009 09:23:38 +0000 From: "Frederick Moreno" X-Original-To: "Lancair Mail" Subject: Oil loss - ring flutter - IO-550 X-Original-Date: Mon, 23 Mar 2009 18:23:32 +0900 X-Original-Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00D4_01C9ABE4.796F4BC0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6838 Importance: Normal Thread-Index: AcmrmQXs3pMsagRUTtK/vftRKt5TWQ== X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-RPD-ScanID: Class unknown; VirusThreatLevel unknown, RefID str=0001.0A150202.49C7551C.00B1,ss=1,fgs=0 This is a multi-part message in MIME format. ------=_NextPart_000_00D4_01C9ABE4.796F4BC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I wrote the group asking for help in diagnosing a puzzling intermittent = oil loss problem. Steve Colwell responded with a note (below) and = suggestions on how to test by measuring crank case pressure during a test flight. =20 =20 We replicated his tests and his results finding little blow by under = ground and flight conditions (less than an inch of water pressure crank case pressure) until I slowly pulled the throttle for descent from 6500 feet. = As the manifold pressure dropped below 18-19 inches we had indications of = huge increases in blow by and ultimately had some oil came up the nylaflow = tubing we had stuffed in the breather and connected to an airspeed indicator in = the cabin. I put out speed brakes, gear, and flaps and brought it home with = 20+ inches of manifold pressure in the descent to minimize the oil mess. Removing the cowl, we found oil splattered as before.=20 =20 It is ring flutter arising from piston problems. Steve had his problem = at 40 hours, and I have 47. I have contacted Performance Engines (engine builder) and ECI (cylinders) and will pull jugs tomorrow. We shall = see.=20 =20 =20 Grrrrr..... =20 Fred Moreno =20 =20 You may have the same problem I had. I was blowing a lot of oil out the crankcase breather too. My Performance Engines IO-550 had forged and = coated pistons that expand at a different rate than the stock Continental or = ECI cast pistons with a steel band for the compression ring land. The compression rings had worn so much in the lands on all 6 pistons they = would =93flutter=94 when power was reduced. The engine had about 40 hours TT. = To test the pressure in the crankcase breather, tap a manometer into the breather about =BD it=92s length or closer to the engine. My engine = would show zero pressure on the ground regardless of power setting. On the takeoff roll still zero. At about 120 knots it would jump to 5=94 and stay = there until power was reduced. When MP was slowly reduced to about 18=94 the pressure in the crankcase vent line climbed to over 30=94. That was = when all the oil was being blown out the breather. The prop was unloaded just = enough to allow the worn rings to flutter up and down in the ring lands and = allow combustion pressure into the crankcase. =20 =20 A mechanic and I spent weeks chasing this problem with ideas from many sources. The good folks at ECI (Engine Components Inc. of San Antonio, = mfg of the cylinders) had it figured out as soon as they heard the symptoms. ECI honed my cylinders and gave me new cast and steel banded pistons = with rings at no charge and within 48 hours. We got the cylinders back on = just in time to fly to Oshkosh. The belly is clean and my catch tank for the Andair Air-Oil Separator is bone dry. =20 =20 Steve Colwell Legacy N15SC ------=_NextPart_000_00D4_01C9ABE4.796F4BC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
I wrote the = group asking=20 for help in diagnosing a puzzling intermittent oil loss problem.  = Steve=20 Colwell responded with a note (below) and suggestions on how to = test by=20 measuring crank case pressure during a test flight.  =
 
We replicated = his tests=20 and his results finding little blow by under ground and = flight=20 conditions (less than an inch of water pressure crank case pressure) = until I=20 slowly pulled the throttle for descent from 6500 feet.  As the = manifold=20 pressure dropped below 18-19 inches we had indications of huge increases = in blow=20 by and ultimately had some oil came up the nylaflow tubing we had = stuffed in the=20 breather and connected to an airspeed indicator in the cabin.  I = put out=20 speed brakes, gear, and flaps and brought it home with 20+ inches = of=20 manifold pressure in the descent to minimize the oil mess.  = Removing=20 the cowl, we found oil splattered as before.
 
It is ring = flutter arising=20 from piston problems.  Steve had his problem at 40 hours, and I = have=20 47.  I have contacted Performance Engines (engine builder) = and  ECI=20 (cylinders) and will pull jugs tomorrow.  We shall see.=20
 
 
Grrrrr.....
 
Fred=20 Moreno
 
 

You=20 may have the same problem I had.  I was blowing a lot of oil out = the=20 crankcase breather too.  My Performance Engines IO-550 had forged = and=20 coated pistons that expand at a different rate than the stock = Continental or ECI=20 cast pistons with a steel band for the compression ring land.  The=20 compression rings had worn so much in the lands on all 6 pistons they = would=20 “flutter” when power was reduced.  The engine had about = 40 hours TT. =20 To test the pressure in the crankcase breather, tap a manometer into the = breather about =BD it’s length or closer to the engine.  My = engine would show=20 zero pressure on the ground regardless of power setting.  On the = takeoff=20 roll still zero.  At about 120 knots it would jump to 5” and = stay there=20 until power was reduced.  When MP was slowly reduced to about = 18” the=20 pressure in the crankcase vent line climbed to over 30”.  = That was when all=20 the oil was being blown out the breather.  The prop was unloaded = just=20 enough to allow the worn rings to flutter up and down in the ring lands = and=20 allow combustion pressure into the crankcase.   =

 

A=20 mechanic and I spent weeks chasing this problem with ideas from many=20 sources.  The good folks at ECI (Engine Components Inc. of San = Antonio, mfg=20 of the cylinders) had it figured out as soon as they heard the = symptoms. =20 ECI honed my cylinders and gave me new cast and steel banded pistons = with rings=20 at no charge and within 48 hours.  We got the cylinders back on = just in=20 time to fly to Oshkosh.  The belly is clean and my catch tank for = the=20 Andair Air-Oil Separator is bone dry. 

 

Steve=20 Colwell  Legacy =  N15SC

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