X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sun, 12 Apr 2009 19:28:32 -0400 Message-ID: X-Original-Return-Path: Received: from betsy.gendns5.com ([65.254.38.234] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTPS id 3578476 for lml@lancaironline.net; Sun, 12 Apr 2009 17:45:35 -0400 Received-SPF: none receiver=logan.com; client-ip=65.254.38.234; envelope-from=paul@tbm700.com Received: from [97.104.178.107] (port=56489 helo=[192.168.1.114]) by betsy.gendns5.com with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.69) (envelope-from ) id 1Lt7U0-0002w1-H2 for lml@lancaironline.net; Sun, 12 Apr 2009 17:44:57 -0400 X-Original-Message-Id: From: paul miller X-Original-To: "Lancair Mailing List" In-Reply-To: Content-Type: multipart/alternative; boundary=Apple-Mail-51--727509879 Mime-Version: 1.0 (Apple Message framework v930.3) Subject: Re: [LML] Bad Vibrations X-Original-Date: Sun, 12 Apr 2009 17:44:55 -0400 References: X-Mailer: Apple Mail (2.930.3) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - betsy.gendns5.com X-AntiAbuse: Original Domain - lancaironline.net X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tbm700.com --Apple-Mail-51--727509879 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed; delsp=yes Content-Transfer-Encoding: quoted-printable Steve, I found some interference on the front left rocker cover as =20 well. We just shimmed the forward left isolation mount on the new =20 mounts and will see if that helps. There was also a hard interference =20= from the baffling plate and it was wearing down some of the cowl hinge =20= in the same area so we had to grind the baffle back a bit. I checked =20= all the gear doors this weekend on jacks and they are all flush and =20 tight so I think the doors are not the problem. I don't have pix of =20= the old isolation mounts but they were 250 hours when the forward left =20= was noticed with cracks and we changed them at 300 a few weeks ago =20 when both forward isolation mounts had cracks. I also changed out the =20= quick drain because it was getting close to the nose gear components =20 and reinstalled the low profile stock oil drain plug until I find =20 something better. Paul Miller N357V Legacy RG s/n 186 On 10-Apr-09, at 8:21 PM, Steve Colwell wrote: > > Vibration #1 was contact of the left front valve cover with the =20 > cowling. The fix was reducing the height of the valve cover and =20 > removing the inner skin and core from the cowl as indicated in the =20 > photos. I verified rocker arm/cover clearance before and after the =20= > =93fix=94. And nope, the stock Continental cover would not have = solved =20 > the clearance problem. > > Vibration #2 was much more interesting. At about 25 hours, I was =20 > over the Cascade Mountains near Redmond when the control stick =20 > started vibrating. At first I thought the engine had gone on Auto-=20 > rough due to mountain/night/big water affecting my imagination. I =20 > let go of the stick, still vibrating , so I did not change anything =20= > thinking it could be the engine coming apart. Within easy glide of =20= > Redmond I reduced power and it slowly went away. Fortunately, I had =20= > Mark Mahnke available to help trouble shoot. He suspected the nose =20= > gear doors and he was right. They were just a little too low and =20 > when the angle of attack was high enough it would shake. Leighton =20 > Mangels and John Halle have another fix for this by glassing up a =20 > little ramp forward of the leading edge of the doors. > > How many hours were on your isolation mounts when they were =20 > =93compressed, tilted and cracked=93? > --Apple-Mail-51--727509879 Content-Type: text/html; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable Steve, I found some = interference on the front left rocker cover as well.   We just = shimmed the forward left isolation mount on the new mounts and will see = if that helps. There was also a hard interference from the baffling = plate and it was wearing down some of the cowl hinge in the same area so = we had to grind the baffle back a bit.   I checked all the gear = doors this weekend on jacks and they are all flush and tight so I think = the doors are not the problem.   I don't have pix of the old = isolation mounts but they were 250 hours when the forward left was = noticed with cracks and we changed them at 300 a few weeks ago when both = forward isolation mounts had cracks.  I also changed out the quick = drain because it was getting close to the nose gear components and = reinstalled the low profile stock oil drain plug until I find something = better.

Paul Miller
N357V
Legacy = RG s/n 186

On 10-Apr-09, at 8:21 PM, Steve = Colwell wrote:
Vibration = #1 was contact of the left front valve cover with the cowling.  The = fix was reducing the height of the valve cover and removing the inner = skin and core from the cowl as indicated in the photos.  I verified = rocker arm/cover clearance before and after the =93fix=94.  And = nope, the stock Continental cover would not have solved the clearance = problem.
Vibration = #2 was much more interesting.  At about 25 hours, I was over the = Cascade Mountains near Redmond when the control stick started = vibrating.  At first I thought the engine had gone on Auto-rough = due to mountain/night/big water affecting my imagination.  I let go = of the stick, still vibrating , so I did not change anything thinking it = could be the engine coming apart.  Within easy glide of Redmond I = reduced power and it slowly went away.  Fortunately, I had Mark = Mahnke available to help trouble shoot.  He suspected the nose gear = doors and he was right.  They were just a little too low and when = the angle of attack was high enough it would shake.  Leighton = Mangels and John Halle have another fix for this by glassing up a little = ramp forward of the leading edge of the = doors.
How many = hours were on your isolation mounts when they were =93compressed, = tilted and cracked=93?