X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 988806 for flyrotary@lancaironline.net; Fri, 17 Feb 2006 09:36:23 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-025-165.carolina.res.rr.com [24.74.25.165]) by ms-smtp-03-eri0.southeast.rr.com (8.13.4/8.13.4) with SMTP id k1HEZV7K012874 for ; Fri, 17 Feb 2006 09:35:34 -0500 (EST) Message-ID: <00e001c633cf$24e4f770$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Apex Seal, Slot Wear was [FlyRotary] Re: Another rotary failure Date: Fri, 17 Feb 2006 09:33:38 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00DD_01C633A5.3B7D84E0" 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_00DD_01C633A5.3B7D84E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageI think the apex seals are one part of the equation, but also the = wear of the apex seal slots in the rotors is a factor. There is a = warning in the Mazda overhaul manual about not using rotors with apex = seals worn beyond specification limit. I found that Mine were over that limit when I tore it down after the = apex seal failure. I know some folks prefer to believe my apex seal = failure was caused by foreign object - but, I am convinced that was not = the case. I believe with the apex seal slot wearing into "V" shape slot leaves = no/little support for the seal when the rotation and combustion forces = causes the seal to lean back against the slot wall. If they wear is = too much there is insufficient support for the seal and it breaks. I = did not know to check for that slot wear limit when I had put the engine = together using used rotors. I now fly with new rotors and Tracy's "unbreakable" apex seals {:>) FWIW Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com ----- Original Message -----=20 From: Russell Duffy=20 To: Rotary motors in aircraft=20 Sent: Monday, February 13, 2006 2:03 PM Subject: [FlyRotary] Re: Another rotary failure No word on the exact cause yet but did learn that Chuck was using = seals from Mazdatrix. They sell only stock Mazda seals as far as I = know. Tracy=20 Is there something wrong with stock seals? I thought they were just = fine for NA engines where detonation almost isn't possible. Your = original engine ran stock seals for 800 or so hours didn't it? = Hopefully, there will be an obvious explanation when he opens it up. =20 On the subject of failures in general, am I the only one who thinks = there have just been way too many of these in the last couple years? In = virtually every case, the engine has been the victim, rather than the = cause of the problem, but to the casual observer, it looks bad for the = rotary. I'd hate to calculate the number of flight hours per serious = problem for currently flying rotaries. I'd also hate for the insurance = companies to do it. Let's hope this trend doesn't continue. =20 Cheers, Rusty (one rotor, no prop) ------=_NextPart_000_00DD_01C633A5.3B7D84E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
I think the apex seals are one part of = the=20 equation, but also the wear of the apex seal slots in the rotors is =  a=20 factor.  There is a warning in the Mazda overhaul manual about not = using=20 rotors with apex seals worn beyond specification limit.
 
  I found that Mine were over that = limit when=20 I tore it down after the apex seal failure.  I know some folks = prefer to=20 believe my apex seal failure was caused by foreign object - but, I am = convinced=20 that was not the case.
 
I believe with the apex seal slot = wearing into=20  "V" shape slot leaves no/little support for the seal when the = rotation and=20 combustion forces causes the seal to lean back against the slot=20 wall.  If  they wear is too much there is insufficient = support=20 for the seal and it breaks.  I did not know to check for that slot = wear=20 limit when I had put the engine together using used rotors.
 
 I now fly with new rotors and = Tracy's=20 "unbreakable" apex seals  {:>)
 
FWIW
 
Ed Anderson
Rv-6A N494BW Rotary=20 Powered
Matthews, NC
eanderson@carolina.rr.com
----- Original Message -----
From:=20 Russell=20 Duffy
Sent: Monday, February 13, 2006 = 2:03=20 PM
Subject: [FlyRotary] Re: = Another rotary=20 failure

No word on the=20 exact cause yet but did learn that Chuck was using seals from = Mazdatrix. =20 They sell only stock Mazda seals as far as I know.
 
Tracy 
 
Is=20 there something wrong with stock seals?  I thought they were just = fine=20 for NA engines where detonation almost isn't possible.  Your = original=20 engine ran stock seals for 800 or so hours didn't it?  Hopefully, = there=20 will be an obvious explanation when he opens it up.  =
 
On=20 the subject of failures in general, am I the only one who thinks there = have=20 just been way too many of these in the last couple years?  In = virtually=20 every case, the engine has been the victim, rather than the cause of = the=20 problem, but to the casual observer, it looks bad for the = rotary.  I'd=20 hate to calculate the number of flight hours per serious problem for = currently=20 flying rotaries.  I'd also hate for the insurance companies = to do=20 it.  Let's hope this trend doesn't=20 continue.  
 
Cheers,
Rusty (one rotor, no=20 prop) 
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