X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 24 May 2011 13:23:22 -0400 Message-ID: X-Original-Return-Path: Received: from elasmtp-curtail.atl.sa.earthlink.net ([209.86.89.64] verified) by logan.com (CommuniGate Pro SMTP 5.4c3j) with ESMTP id 4992523 for lml@lancaironline.net; Mon, 23 May 2011 23:58:00 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.64; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=bxXlYsa/F64Pw66WQ+NwuAkCWnxgV23+Rkd5wxNy1fxhA2HP/tFvUc/OS2nkHAIx; h=Received:From:Mime-Version:Content-Type:Subject:Date:In-Reply-To:To:References:Message-Id:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [216.57.118.194] (helo=[192.168.1.131]) by elasmtp-curtail.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1QOikI-0004n9-9I for lml@lancaironline.net; Mon, 23 May 2011 23:57:26 -0400 From: Colyn Case Mime-Version: 1.0 (Apple Message framework v1082) Content-Type: multipart/alternative; boundary=Apple-Mail-467--662752243 Subject: Re: [LML] Re: FW: LNC2 Vibration Issues X-Original-Date: Mon, 23 May 2011 23:57:25 -0400 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: <8D6290AB-95A1-486E-B10B-4B73E24229F8@earthlink.net> X-Mailer: Apple Mail (2.1082) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da940e181eeed75c12f14d4687ff3ea9ad180350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 216.57.118.194 --Apple-Mail-467--662752243 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Tom, based on this and previous descriptions it sounds like the vibration = occurs with higher power or higher torque. On my airplane I had a problem with the left intake manifold rubbing on = the cowl at certain power settings. I wonder if you are getting some interference between something on the = engine and some part of the cowl in the presence of torque. Colyn On May 23, 2011, at 8:03 AM, TOM GARDINER wrote: >=20 >=20 > Folks, > =20 > I appreciate the great response from the LML list to my vibration = problem. I have checked everything that was mentioned in the emails. = Most people including myself suspect a tracking issue. But here is the = rub: On the ground the tracking appears to be perfect with the engine = noyt running. Now this is where it gets interesting, in cruise and = level flight at 24"/2400RPM I can see some dither on my ASI and feel the = vibration thorugh the airframe. Now if I point the plane downhill at = say 700fpm or more and the same power setting everything smoothes out!=20= > =20 > This to me suggests something in the prop tracking or engine mounting = arrangement since right turning P factor is less with the nose below the = horizon. Any ideas? > =20 > Thanks > =20 > Tom > =20 > LNC2 50 hrs --Apple-Mail-467--662752243 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii Tom,

based on this and previous = descriptions it sounds like the vibration occurs with higher power or = higher torque.

On my airplane I had a problem with the left = intake manifold rubbing on the cowl at certain power = settings.

I wonder if you are getting some interference = between something on the engine and some part of the cowl in the = presence of = torque.

Colyn

On May = 23, 2011, at 8:03 AM, TOM GARDINER wrote:

Folks,

I appreciate the great response from the LML list = to my vibration problem. I have checked everything that was = mentioned in the emails. Most people including myself suspect a = tracking issue. But here is the rub: On the ground the tracking = appears to be perfect with the engine noyt running. Now this is = where it gets interesting, in cruise and level flight at = 24"/2400RPM I can see some dither on my ASI and feel the = vibration thorugh the airframe. Now if I point the plane downhill = at say 700fpm or more and the same power setting everything smoothes = out!
This to = me suggests something in the prop tracking or engine mounting = arrangement since right turning P factor is less with the nose below the = horizon. Any ideas?

Tom

LNC2 50 = hrs

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