X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Mon, 23 Jan 2006 01:50:41 -0500 Message-ID: X-Original-Return-Path: Received: from smtp111.sbc.mail.mud.yahoo.com ([68.142.198.210] verified) by logan.com (CommuniGate Pro SMTP 5.0.7f) with SMTP id 941154 for lml@lancaironline.net; Sun, 22 Jan 2006 13:18:29 -0500 Received-SPF: none receiver=logan.com; client-ip=68.142.198.210; envelope-from=elippse@sbcglobal.net Received: (qmail 8387 invoked from network); 22 Jan 2006 18:17:43 -0000 Received: from unknown (HELO Computerroom) (elippse@sbcglobal.net@66.122.72.99 with login) by smtp111.sbc.mail.mud.yahoo.com with SMTP; 22 Jan 2006 18:17:43 -0000 X-Original-Message-ID: <002201c61f80$23c8e080$63487a42@Computerroom> From: "Paul Lipps" X-Original-To: Subject: "Ram" air X-Original-Date: Sun, 22 Jan 2006 10:17:43 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001F_01C61F3D.14E20260" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_001F_01C61F3D.14E20260 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Here's the formula I use to determine induction aperture area, sq. in.: = RPM/60 x CD!/2 x 1.25 / (TAS, mph, x 22/15 x 12) The 1.25 gives a 25% = increase to take care of inlet losses and the need for increased area at = low speed. My MAP always calculates out to PSTATIC + PDYNAMIC - PCARB = DROP. For the O-235, the carb drop ranges from 1.5" at sea-level to = about 1.2" at 12,500'. At 8000' dalt, 250mphTAS, dynamic pressure should = be 1.68". If you see more MAP rise than this, you might have a source of = pixie dust handy! My induction air inlet is the "chin" style to take = advantage of the slight velocity increase from the air displaced by the = spinner; my cooling air inlets also try to take advantage of this by = having the inside edge in-line with the edge of the spinner. I expand = the air into a 10" x 4" K&N filter, with a nose-gear operated bypass = around the filter. This doesn't seem to be necessary, as I see no MAP = change when the bypass opens. That's probably due to the air being = slowed down so much through the filter, so there is minimal pressure = drop. One thing to mention, however. Jeff's/Chris' "Miss Gianna" is = using the ELIPPSE prop I designed for them and for the Tom Aberle/Andrew = Buehler "Phantom", the 2004 and 2005 Gold Championship winner, which is = somewhat similar in planform to the three-blade I designed for my = Lancair. This design has true airfoil and helix angle all the way into = the spinner, and promotes, rather than blocks the airflow in the hub = region, as opposed to almost all fixed-pitch and the majority of CS = props with their god-awful hub shapes! This prop-induced blocking of = airflow is the reason for mounting cooling inlets farther out from = center where the prop is actually inducing airflow. At least, so said = John Roncz! ------=_NextPart_000_001F_01C61F3D.14E20260 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Here's the formula I use to determine induction = aperture=20 area, sq. in.: RPM/60 x CD!/2 x 1.25 / (TAS, mph, x 22/15 = x 12) The=20 1.25 gives a 25% increase to take care of inlet losses and the need = for increased area at low speed. My MAP always calculates out to = PSTATIC + PDYNAMIC - PCARB DROP. For = the O-235, the=20 carb drop ranges from 1.5" at sea-level to about 1.2" at 12,500'. At = 8000' dalt,=20 250mphTAS, dynamic pressure should be 1.68". If you see more MAP rise = than this,=20 you might have a source of pixie dust handy! My induction air inlet is = the=20 "chin" style to take advantage of the slight velocity increase from the = air=20 displaced by the spinner; my cooling air inlets also try to take = advantage=20 of this by having the inside edge in-line with the edge of the spinner. = I expand=20 the air into a 10" x 4" K&N filter, with a nose-gear operated bypass = around=20 the filter. This doesn't seem to be necessary, as I see no MAP change = when the=20 bypass opens. That's probably due to the air being slowed down so much = through=20 the filter, so there is minimal pressure drop. One thing to = mention,=20 however. Jeff's/Chris' "Miss Gianna" is using the ELIPPSE prop I = designed=20 for them and for the Tom Aberle/Andrew Buehler "Phantom", the 2004 = and 2005=20 Gold Championship winner, which is somewhat similar in planform to = the=20 three-blade I designed for my Lancair. This design has true airfoil and = helix=20 angle all the way into the spinner, and promotes, rather than blocks=20 the airflow in the hub region, as opposed to almost all fixed-pitch = and the=20 majority of CS props with their god-awful hub shapes! This prop-induced = blocking=20 of airflow is the reason for mounting cooling inlets farther out from = center=20 where the prop is actually inducing airflow. At least, so said John=20 Roncz!

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