X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 27 Feb 2006 00:21:59 -0500 Message-ID: X-Original-Return-Path: Received: from imo-m14.mx.aol.com ([64.12.138.204] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 998724 for lml@lancaironline.net; Sun, 26 Feb 2006 11:49:07 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.138.204; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m14.mx.aol.com (mail_out_v38_r7.3.) id q.2d6.38f1e2c (4214) for ; Sun, 26 Feb 2006 11:48:15 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <2d6.38f1e2c.313335cf@aol.com> X-Original-Date: Sun, 26 Feb 2006 11:48:15 EST Subject: Re: [LML] Re: LNC2 Cowl gap question X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1140972495" X-Mailer: 9.0 Security Edition for Windows sub 5300 X-Spam-Flag: NO -------------------------------1140972495 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 2/26/2006 1:06:11 A.M. Central Standard Time, N4ZQ@comcast.net writes: I have set the gap between spinner and cowl to approximately .175" all around. I'd like to close in this gap a bit with an additional 1BID on the face of the cowl. So, in everyone's opinion, how small a gap would be too small and result in eventual contact due to engine sag? Angier, Consider that the engine also moves around from torque applications. Think of the problem as diagrammed by an H, where the left vertical (L) is the distance between the elastometric supports of the engine, the right vertical (R) is the diameter of the spinner and the horizontal (C) is the crank length (distance from the mount to the spinner). If the engine sags, the displacement, as measured by the leg of a right triangle, is proportional for each similar triangle formed from the legs of the H as defined above. Suppose L=15, R=10 and C=30 (measure for yourself). Let's say the engine sagged or was displaced 1/2 inch as measured at the spinner. That is about 1/4 inch at the bottom mount in the same plane (gee, I wonder why my soft bottom mounts are shimmed 1/4 inch?). How far would the bottom of the spinner move back? The similar triangle would have a leg of 1/6 inch but the triangle thru the center would make it 1/12 inch. Oh, also the center back of the engine moved a bit aft when it sagged - about 1/8 inch (maybe less because the back of the top mount moved forward, too). So, an EWAG of 5/24 inch is .21 inches or so of spinner edge movement in the above example. Hmmm, perhaps the gap is a bit tight - maybe take out a washer to move the spinner back plate a bit forward (.0625) or fly in primer and fix the cowl scratches, if any, later. BTW, the exhaust pipes move around in a similar fashion. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) -------------------------------1140972495 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

In a message dated 2/26/2006 1:06:11 A.M. Central Standard Time,=20 N4ZQ@comcast.net writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I have=20 set the gap between spinner and cowl to approximately .175"
all=20 around. I'd like to close in this gap a bit with an additional
1= BID=20 on the face of the cowl. So, in everyone's opinion, how small a
= gap=20 would be too small and result in eventual contact due to engine=20 sag?

Angier,

Consider that the engine also moves around from torque=20 applications.

Think of the problem as diagrammed by an H, where the left vertical=20 (L) is the distance between the elastometric supports of the=20 engine, the right vertical (R) is the diameter of the spinner= and=20 the horizontal (C) is the crank length (distance from the mount to= the=20 spinner).

If the engine sags, the displacement, as measured by the leg of a right= =20 triangle, is proportional for each similar triangle formed from the legs of=20= the=20 H as defined above.

Suppose L=3D15, R=3D10 and C=3D30 (measure for yourself). Le= t's say=20 the engine sagged or was displaced 1/2 inch as measured at the spinner. = ;=20 That is about 1/4 inch at the bottom mount in the same plane (gee, I wo= nder=20 why my soft bottom mounts are shimmed 1/4 inch?). How far would the bo= ttom=20 of the spinner move back? The similar triangle would have a leg of 1/6= =20 inch but the triangle thru the center would make it 1/12 inch.&nbs= p;=20 Oh, also the center back of the engine moved a bit aft when it=20 sagged - about 1/8 inch (maybe less because the back of the top mount m= oved=20 forward, too). So, an EWAG of 5/24 inch is .21 inches or so of=20 spinner edge movement in the above example. Hmmm, perhaps the gap is a= bit=20 tight - maybe take out a washer to move the spinner back plate a bit forward= =20 (.0625) or fly in primer and fix the cowl scratches, if any, later.

BTW, the exhaust pipes move around in a similar fashion.

Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL=20 (KARR)

-------------------------------1140972495--