X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 26 Nov 2011 10:22:55 -0500 Message-ID: X-Original-Return-Path: Received: from nm31-vm7.bullet.mail.ne1.yahoo.com ([98.138.229.47] verified) by logan.com (CommuniGate Pro SMTP 5.4.2) with SMTP id 5215080 for lml@lancaironline.net; Sat, 26 Nov 2011 09:17:50 -0500 Received-SPF: none receiver=logan.com; client-ip=98.138.229.47; envelope-from=casey.gary@yahoo.com Received: from [98.138.90.52] by nm31.bullet.mail.ne1.yahoo.com with NNFMP; 26 Nov 2011 14:17:14 -0000 Received: from [98.138.89.245] by tm5.bullet.mail.ne1.yahoo.com with NNFMP; 26 Nov 2011 14:17:14 -0000 Received: from [127.0.0.1] by omp1059.mail.ne1.yahoo.com with NNFMP; 26 Nov 2011 14:17:14 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 832560.50744.bm@omp1059.mail.ne1.yahoo.com Received: (qmail 49467 invoked by uid 60001); 26 Nov 2011 14:17:14 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=LtOmd77kWwjWBPdc+6WjOyoyFBtv9YoL271K4xxYVTLLmlPXuZQN4I6/d8VVqV6hGjiLtjXWdhSGKzCc51+suuTakooMmu3+VU5qNIbxiDrOGmqOlTUt+q6s3juTaldbPHLApn9/0hw7BxsO8zXE1FGG317YhUs7vxT2rkR+1cQ=; X-YMail-OSG: hUddmBoVM1nWrHBeQhrlRMevo4ZRs_qEBLP8C5WSC0jQiR5 P.d.ByCMMspmD6WSUVlAAxPBzjbDsRBqcrR6.ijJDD4BqBjP27sIlhUIKpxp ZL8LkomNkwWuwTyhfE2W1GB15Lu3DwSoRKB9DP0nQYxGvB_tNbolB4CLNNev GVdEPjbbSF80Z7Zyi8aJUDSxOeKbJd8qRxWOF6Ztw6lvkX9G.D5xYWgSoM7R cp4M9f6KsGlEqag7lSjczZXeL3uPv.QoZZBRWNClHIr4EFyu0wksJWWEdr6B Rg3TS3Oe1x8Wm50bVqufNJ.mH0cIkfXR3q9TfPM2TXVxuoRHjaGaBBKDQ1KJ 4tdEciAb5psVsGSlUW6vSP_DLmQKabtEcHIXg9bAXy.QI.OLFQyFDHs67y9j M5_ENbxZEcW34nnGWjT.CFoMc4Bs.dR5qnkncTH0- Received: from [50.82.245.123] by web125603.mail.ne1.yahoo.com via HTTP; Sat, 26 Nov 2011 06:17:14 PST X-Mailer: YahooMailWebService/0.8.115.325013 References: X-Original-Message-ID: <1322317034.34654.YahooMailNeo@web125603.mail.ne1.yahoo.com> X-Original-Date: Sat, 26 Nov 2011 06:17:14 -0800 (PST) From: Gary Casey Reply-To: Gary Casey Subject: Re: E-Mag/P-Mag X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="933233344-380489448-1322317034=:34654" --933233344-380489448-1322317034=:34654 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Scott,=0AThanks for the information.=A0 I took your numbers and did a crude= reqression analysis and came up with the following:=A0 The advance increas= es by 2.2 degrees per thousand rpm above 1700 and 0.85 degrees per inche of= manifold pressure below 28.=A0 Just gives a rough idea of how it works.=0A= Gary=0A=A0=0AFrom Scott:=0ARestricting my comments to Lycoming engines (320= , 360), one would note that 25 DBTDC is the fixed timing delivered by stan= dard magnetos and that timing is adequate for a wide range of engine opera= tions. My injected 320 engine has a 9:1 CR and uses a base timing of 20 D= BTDC. Normal ROP cruise settings in the 4000 to 9000 MSL range and 2500 R= PM (say 21 to 25 MAP), the timing is between 24 and 26 DBTDC. At takeoff = and low altitude race power settings (2760 -2600 RPM, WOT, 28-30 MAP), the= timing is about 22-23 DBTDC. At leaned idle/taxi power (<10" MAP, <1100 = RPM) the timing is about 34-35 DBTDC. At altitudes 10000- 14000 MSL, 2500= RPM, WOT and LOP the timings are generally 29-31 DBTDC.=0AScott Krueger --933233344-380489448-1322317034=:34654 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable

Scott,

Thanks for the information. I took your numbers and did a crude re= qression analysis and came up with the following: The advance increas= es by 2.2 degrees per thousand rpm above 1700 and 0.85 degrees per inche of= manifold pressure below 28. Just gives a rough idea of how it works.=

Gary

From Scott:

Restrictin= g my comments to Lycoming engines (320, 360), one would note that 25 DBTDC= is the fixed timing delivered by standard magnetos and that timing is ade= quate for a wide range of engine operations. My injected 320 engine has a= 9:1 CR and uses a base timing of 20 DBTDC. Normal ROP cruise settings in= the 4000 to 9000 MSL range and 2500 RPM (say 21 to 25 MAP), the timing is= between 24 and 26 DBTDC. At takeoff and low altitude race power settings (2760 -2600 RPM, WOT, 28-30 MAP), the timing is about 22-23 DBTD= C. At leaned idle/taxi power (<10" MAP, <1100 RPM) the timing is ab= out 34-35 DBTDC. At altitudes 10000- 14000 MSL, 2500 RPM, WOT and LOP the= timings are generally 29-31 DBTDC.

Scott Krueger

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