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 4.3.5) with ESMTP id 1020588 for flyrotary@lancaironline.net; Fri, 24 Jun 2005 15:08:25 -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 j5OJ7bl9001121 for ; Fri, 24 Jun 2005 15:07:38 -0400 (EDT) Message-ID: <002301c578ef$fdb658f0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause Date: Fri, 24 Jun 2005 15:07:39 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0020_01C578CE.766B8080" 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_0020_01C578CE.766B8080 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageWell, Rusty,=20 I did mention that the engine was so tight that it would not idle below = 2100 rpm the first run up. It gradually got looser as if something that = was causing the friction was wearing down. After approx 2 hours the = friction was gone and the engine ran and felt normal. I find it hard to believe as well, but seeing as how the unlikely = continues to happen to me I am getting less hard to convince {:>). =20 I am certainly open to other hypothesis that explains the two hot spots = across from one another. I agree it doesn't seem possible, but it sure = looks like something was rubbing and then pushing/cocking the rotor over = at that point. My nephew took some photos when we disassembled the = engine, but I have not yet received them. I'll post them to the list = once I do. Naturally, I should have pulled the engine apart again - but, in too = much of a hurry to get the aircraft home - so I got to do it again {:>) Ed ----- Original Message -----=20 From: Russell Duffy=20 To: Rotary motors in aircraft=20 Sent: Friday, June 24, 2005 1:01 PM Subject: [FlyRotary] Re: Engine Rebuild - Coolant Leak Cause At this point, it appears that one of the triangular pieces of the = apex seal (could not find it anywhere) left its proper position = (undoubtedly during my assembly) and got lodged at the end (apex) of one = of the rotors. May have been held their by some combination of the = corner and side seal. =20 Hi Ed, Are you saying you think the little triangle piece came out of the = slot, and was wedged flat between the side of the rotor, and the side = housing? =20 The rotor running clearance is supposed to be .0047" to .010", so 2mm = (.0787") seal ain't gonna fit between the rotor and the housing, if = that's what you were saying. I would bet that you wouldn't be able to = turn the engine at all if you bolted it together that way.=20 OR, were you saying you think the triangle piece of seal was still in = the apex seal slot, but being pushed toward the side of the rotor, = similar to having a seal that was too long? =20 In either case, the wear you would see on the opposite side, would be = from the rotor gear, or thrust ring (whichever side that happened to be) = of the rotor, since those are raised above the side of the rotor itself. = The damage to the side housing would be similar to my oil out I would = imagine. =20 If the triangle piece of seal was missing, I'd wonder if that wouldn't = let combustion pressure get behind the corner seals (particularly the = side with the missing piece), and push outward creating the extra = friction. Of course I'd wonder why that didn't happen at two places, = since that apex seal is on the leading, and trailing edge of two faces = of the rotor. =20 Do you have any pictures of these hot spots? =20 Cheers, Rusty=20 ------=_NextPart_000_0020_01C578CE.766B8080 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Well, Rusty,
 
I did mention that the engine was so tight that = it would=20 not idle below 2100 rpm the first run up. It gradually got looser = as if=20 something that was causing the friction was wearing down.  = After=20 approx 2 hours the friction was gone and the engine ran and felt=20 normal.
 
 I find it hard to believe as well, but = seeing as how=20 the unlikely continues to happen to me I am getting less hard to = convince=20 {:>). 
 
I am certainly open to other hypothesis that = explains the=20 two hot spots across from one another.   I agree it doesn't = seem=20 possible, but it sure looks like something was rubbing and then = pushing/cocking=20 the rotor over at that point.    My nephew took some = photos when=20 we disassembled the engine, but I have not yet received them.  I'll = post=20 them to the list once I do.
 
Naturally, I should have pulled the engine apart = again -=20 but, in too much of a hurry to get the aircraft home - so I got to do it = again=20 {:>)
 
Ed
----- Original Message -----
From:=20 Russell=20 Duffy
Sent: Friday, June 24, 2005 = 1:01 PM
Subject: [FlyRotary] Re: Engine = Rebuild -=20 Coolant Leak Cause

At = this point,=20 it appears that one of the triangular pieces of the apex seal (could = not find=20 it anywhere) left its proper position (undoubtedly during my assembly) = and got=20 lodged at the end (apex) of one of the rotors. May have been held = their by=20 some combination of the corner and side seal.  
 
 
Hi=20 Ed,
 
Are you = saying you think the=20 little triangle piece came out of the slot, and was wedged flat = between the=20 side of the rotor, and the side housing? =20
 
The rotor running = clearance is=20 supposed to be .0047" to .010", so  2mm (.0787") seal ain't gonna = fit=20 between the rotor and the housing, if that's what you were = saying.  I=20 would bet that you wouldn't be able to turn the engine at all if you = bolted it=20 together that way. 
 
OR, were you saying = you think the=20 triangle piece of seal was still in the apex seal slot, but being = pushed=20 toward the side of the rotor, similar to having a seal that was too=20 long?  
 
In either case, the = wear you=20 would see on the opposite side, would be from the rotor gear, or = thrust=20 ring (whichever side that happened to be) of the rotor, since=20 those are raised above the side of the rotor itself. = The damage=20 to the side housing would be similar to my oil out I would=20 imagine.  
 
If the triangle = piece of=20 seal was missing, I'd wonder if that wouldn't let combustion pressure = get=20 behind the corner seals (particularly the side with the missing = piece),=20 and push outward creating the extra friction.  Of course I'd = wonder=20 why that didn't happen at two places, since = that apex seal is=20 on the leading, and trailing edge of two faces of the = rotor. =20    
 
Do you have any = pictures of=20 these hot spots?  
 
Cheers,
Rusty=20
 
 
 
------=_NextPart_000_0020_01C578CE.766B8080--