X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 14 Dec 2005 07:52:38 -0500 Message-ID: X-Original-Return-Path: Received: from [64.12.137.3] (HELO imo-m22.mail.aol.com) by logan.com (CommuniGate Pro SMTP 5.0.4) with ESMTP id 881394 for lml@lancaironline.net; Wed, 14 Dec 2005 00:32:40 -0500 Received-SPF: pass receiver=logan.com; client-ip=64.12.137.3; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m22.mx.aol.com (mail_out_v38_r6.3.) id q.27d.22daee5 (2519) for ; Wed, 14 Dec 2005 00:31:50 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <27d.22daee5.30d10846@aol.com> X-Original-Date: Wed, 14 Dec 2005 00:31:50 EST Subject: Re: [LML] Re: Air filters X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1134538310" X-Mailer: 9.0 Security Edition for Windows sub 5300 X-Spam-Flag: NO -------------------------------1134538310 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 12/13/2005 10:16:18 P.M. Central Standard Time, N4ZQ@comcast.net writes: The K&N filter people say their filter material is designed to pass air at the rate of 6cf/min so it's relatively easy to calculate the filter area and end up with a cfm rating for the filter. Now, the question is... how does one equate lbs/hr to cfm in order to come up with the right size filter? Try this, Your engine is an air pump. For a 4 cylinder aircraft engine each revolution has 1 cylinder drawing in air, 1 compressing air, 1 firing and 1 exhausting combustion products. Thus, 1 revolution consumes 1/4 x 360 cubic inches or 90 ci or .625 cubic feet. At 2700 rpm and WOT, that's 2700 x .675 cf or 1688 cfm. Lbs/Hr depends on air density. K&N has a formula for size: filter area = (CI x RPM)/20839 filter area = (360 x 2700)/20839 = 47 square inches of effective filter area, add .75" to each dimension for actual since air doesn't flow well at the edge of the filter. Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Merry Christmas to all! -------------------------------1134538310 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

In a message dated 12/13/2005 10:16:18 P.M. Central Standard Time,=20 N4ZQ@comcast.net writes:

<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>The=20 K&N filter people say their filter material is designed to pass =20
air at the rate of 6cf/min so it's relatively easy to calculate the&nb= sp;=20
filter area and end up with a cfm rating for the filter. Now, the = ;=20
question is... how does one equate lbs/hr to cfm in order to come up&n= bsp;=20
with the right size filter?

Try this,

Your engine is an air pump. For a 4 cylinder aircraft engine each= =20 revolution has 1 cylinder drawing in air, 1 compressing air, 1 firing and&nb= sp;1=20 exhausting combustion products. Thus, 1 revolution consumes 1/4 x 360=20 cubic inches or 90 ci or .625 cubic feet. At 2700 rpm and WOT, that's 2700 x= =20 .675 cf or 1688 cfm. Lbs/Hr depends on air density.

K&N has a formula for size:

filter area =3D (CI x RPM)/20839

filter area =3D (360 x 2700)/20839 =3D 47 square inches of effective fi= lter=20 area, add .75" to each dimension for actual since air doesn't flow well at t= he=20 edge of the filter.=20

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

Mer= ry=20 Christmas to all!

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