Return-Path: Sender: (Marvin Kaye) To: lml Date: Fri, 12 Sep 2003 10:13:39 -0400 Message-ID: X-Original-Return-Path: Received: from imo-r05.mx.aol.com ([152.163.225.101] verified) by logan.com (CommuniGate Pro SMTP 4.1.3) with ESMTP id 2576962 for lml@lancaironline.net; Fri, 12 Sep 2003 08:54:22 -0400 Received: from Sky2high@aol.com by imo-r05.mx.aol.com (mail_out_v36_r1.1.) id q.1e9.f822afd (4410) for ; Fri, 12 Sep 2003 08:53:15 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: <1e9.f822afd.2c931bba@aol.com> X-Original-Date: Fri, 12 Sep 2003 08:53:14 EDT Subject: Re: [LML] LNC2: sagging motor mounts X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1063371194" X-Mailer: 9.0 for Windows sub 1030 -------------------------------1063371194 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en In a message dated 9/11/2003 10:49:42 PM Central Daylight Time,=20 olsen25@comcast.net writes: have about 35 hours on my 320 and have the traditional 1/4" =E2=80=93 3/8= =E2=80=9D sag at=20 the spinner. The engine is mounted on the Barry vibration isolators that=20 Lancair sells. My intent was to align the cowl with the sag in mind in hope= s that=20 the engine would eventually match up. Well, the way the cowl turned out it=20= was=20 aligned perfectly before the first flight. Within the first 10-15 hours I=20 got all the sag I=E2=80=99m going to get. My question for the group is: how many area washers should I put under the=20 lower two dynafocal pads to shim the engine up? From past postings that I c= an=20 find I am guessing at 2. What say you all Dan, I am surprised that you have that much sag so soon on the stiffer Barry=20 mounts. This is usually more of a problem with the softer Lord mounts. =20 In any event, consider the engine mount to spinner linkage much the same way= =20 the leg bone is connected to the knee bone and the knee bone is connected to= =20 the foot bone, Dem Bones - Dem Bones......... Think about a lazy ell (L) wi= th=20 the right angle as the pivotal upper engine mount, the end of the short leg=20= at=20 the bottom engine mount and the end of the long leg at the spinner. If the=20 short leg is 1 foot, the long leg is 2 feet and a spacer is used to move the= =20 short leg forward 1/8", the long leg would move up 1/4". So, measure the=20 distance between the mounts and from the top mount to the spinner bulkhead a= nd=20 compute how thick a spacer is needed to return the engine to its' faired pos= ition. A common problem is to use the wrong length bolt or to torque the nut onto=20 the shoulder of the bolt. The heat-proof steel locking nut is longer than=20 others and you should see no more than three threads showing after torqueing= the=20 bolt. Use as many washers as necessary to satisfy this condition. If the n= ut=20 is torqued onto the bolt shoulder, the internal bushing is not tight to both= =20 rubbers and the mount "floats" the engine which can result in excessive sag=20= and=20 harmful vibration. Scott Krueger Sky2high@aol.com II-P N92EX IO320 Aurora, IL (KARR) -------------------------------1063371194 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Content-Language: en

In a message dated 9/11/2003 10:49:42 PM Central Daylight Time, olsen25= @comcast.net writes:

have about 35 hours on my 320 and have the traditio= nal 1/4" =E2=80=93 3/8=E2=80=9D sag at the spinner. The engine is moun= ted on the Barry vibration isolators that Lancair sells. My intent was= to align the cowl with the sag in mind in hopes that the engine would event= ually match up. Well, the way the cowl turned out it was aligned perfe= ctly before the first flight. Within the first 10-15 hours I got all t= he sag I=E2=80=99m going to get.

My question for the group is: how many area washers= should I put under the lower two dynafocal pads to shim the engine up? = ; From past postings that I can find I am guessing at 2. What say you=20= all

Dan,

I am surprised that you have that much sag so soon on the stiffer Barry= mounts. This is usually more of a problem with the softer Lord mounts= .

In any event, consider the engine mount to spinner linkage much th= e same way the leg bone is connected to the knee bone and the = ;knee bone is connected to the foot bone, Dem Bones - Dem Bones........= . Think about a lazy ell (L) with the right angle as the pivotal upper= engine mount, the end of the short leg at the bottom engine mount and the e= nd of the long leg at the spinner. If the short leg is 1 foot, the long= leg is 2 feet and a spacer is used to move the short leg forward = 1/8", the long leg would move up 1/4". So, measure the distance betwee= n the mounts and from the top mount to the spinner bulkhead and compute how=20= thick a spacer is needed to return the engine to its' faired position.

A common problem is to use the wrong length bolt or to torque the nut o= nto the shoulder of the bolt. The heat-proof steel locking nut is long= er than others and you should see no more than three threads showing after t= orqueing the bolt. Use as many washers as necessary to satisfy this co= ndition. If the nut is torqued onto the bolt shoulder, the internal bu= shing is not tight to both rubbers and the mount "floats" the engine which c= an result in excessive sag and harmful vibration.

Scott Krueger
Sky2high@aol.com
II-P N92EX IO320 Aurora, IL (KARR)

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