X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 12 Jul 2007 21:02:59 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m25.mx.aol.com ([64.12.137.6] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2174296 for lml@lancaironline.net; Thu, 12 Jul 2007 18:32:39 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.6; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m25.mx.aol.com (mail_out_v38_r9.2.) id q.c55.19995017 (58435) for ; Thu, 12 Jul 2007 18:32:00 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Thu, 12 Jul 2007 18:32:00 EDT Subject: Re: [LML] Dimpled Firewalls X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1184279519" X-Mailer: 9.0 Security Edition for Windows sub 5365 X-Spam-Flag: NO -------------------------------1184279519 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 7/12/2007 5:02:18 P.M. Central Daylight Time, sbej@verizon.net writes: What is everyone doing about the dimpled firewall effect you get when you tighten your motor mount bolts up to the hard firewall with 3/8" of soft fiberfrax behind it? I thought about putting phenolic spacers behind each bolt but not really interested in the time to do it. I dont care if my firewall is dimpled I just want to make sure its safe. Anyone else have the dimple effect? Bryan, Don't do it the way you want - over time the frax will compress and the tension of the mount bolts will be wrong. Get large area washers (probably 2) and cut away the frax around the mount holes so the washers fit. Every one or two years, you should check the motor mount to firewall torque value. If these loosen up, vibration is rampant. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Darwinian culling phrase: Watch This! ************************************** Get a sneak peak of the all-new AOL at http://discover.aol.com/memed/aolcom30tour -------------------------------1184279519 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 7/12/2007 5:02:18 P.M. Central Daylight Time,=20 sbej@verizon.net writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>What is=20 everyone doing about the dimpled firewall effect you get when 
yo= u=20 tighten your motor mount bolts up to the hard firewall with 3/8"  of=20 soft fiberfrax behind it?    I thought about putting phenolic&nb= sp;=20
spacers behind each bolt but not really interested in the time to do&n= bsp;=20
it.  I dont care if my firewall is dimpled I just want to make=20 sure 
its safe.  Anyone else have the dimple=20 effect?
Bryan,
 
Don't do it the way you want - over time the frax will compress and the= =20 tension of the mount bolts will be wrong.  Get large area washers (prob= ably=20 2) and cut away the frax around the mount holes so the washers fit.
 
Every one or two years, you should check the motor mount to firewall to= rque=20 value.  If these loosen up, vibration is rampant.
 
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL=20 (KARR)

Darwinian culling phrase: Watch=20 This!



Get a sneak p= eak of the all-new AOL.com.
= -------------------------------1184279519--