X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 26 Nov 2011 18:12:26 -0500 Message-ID: X-Original-Return-Path: Received: from imr-da02.mx.aol.com ([205.188.105.144] verified) by logan.com (CommuniGate Pro SMTP 5.4.2) with ESMTP id 5260015 for lml@lancaironline.net; Sat, 26 Nov 2011 14:00:11 -0500 Received-SPF: pass receiver=logan.com; client-ip=205.188.105.144; envelope-from=Sky2high@aol.com Received: from mtaomg-da02.r1000.mx.aol.com (mtaomg-da02.r1000.mx.aol.com [172.29.51.138]) by imr-da02.mx.aol.com (8.14.1/8.14.1) with ESMTP id pAQIxR5T031266 for ; Sat, 26 Nov 2011 13:59:27 -0500 Received: from core-mtb004a.r1000.mail.aol.com (core-mtb004.r1000.mail.aol.com [172.29.234.205]) by mtaomg-da02.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 753CEE00008D for ; Sat, 26 Nov 2011 13:59:27 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <17435.5a7c6aad.3c02910f@aol.com> X-Original-Date: Sat, 26 Nov 2011 13:59:27 -0500 (EST) Subject: Re: [LML] Re: E-Mag/P-Mag X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_17435.5a7c6aad.3c02910f_boundary" X-Mailer: AOL 9.6 sub 168 X-Originating-IP: [24.1.9.48] x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:443664128:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d338a4ed1370f6f42 --part1_17435.5a7c6aad.3c02910f_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Gary and Chris, Here is detailed info from my most recent long trip (ARR-EDC-PLK-ARR). Perhaps you can deduce more as the RPM was in the 2480 to 2500 range for all legs. ARR->EDC 820 NM 4.7 hrs block to block. Flown at 6500 MSL to avoid higher headwinds at higher altitudes and LOP (economy) to eliminate a fuel stop. Conditions were constant for the entire trip and all four data points are very similar. OAT 19C, Dalt 7500, KIAS 168, KTAS 187, 24.8" MAP, 2480 RPM, 7.4 GPH and 24.5 DBTDC. Actual flight time was 4.3 hours and I put 32.1 gallons at EDC having been left with a reserve of 9.9 gals. EDC->PLK 440 NM 2.4 hours block to block. Flown at 9500 MSL to use the winds and ROP (best power) to go fast. OAT 16C, Dalt 11000, KIAS 163, KTAS 190 (Ahhh, over PGO GS 208 Kts), 22.1" MAP, 2490 RPM, 8.5 GPH and 27 DBTDC. PLK-> ARR 380 NM 2.2 hours block to block. Flown at 7500 MSL and ROP. OAT 18C, Dalt 8700, KIAS 171, KTAS 194, 24.1" MAP, 2500 RPM, 9.8 GPH and 25 DBTDC. Scott Krueger IO 320, 9:1 CR, unfiltered ram air, dual Plasma III EI, Hartzell CS prop, uh, a few drag reducers.... In a message dated 11/26/2011 9:23:27 A.M. Central Standard Time, casey.gary@yahoo.com writes: Scott, Thanks for the information. I took your numbers and did a crude reqression analysis and came up with the following: The advance increases 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: Restricting 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 adequate 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 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. Scott Krueger --part1_17435.5a7c6aad.3c02910f_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Gary and Chris,

Here is detailed info from my most recent long trip=20 (ARR-EDC-PLK-ARR). Perhaps you can deduce more as the RPM was in the = 2480=20 to 2500 range for all legs.

ARR->EDC 820 NM 4.7 hrs block to block. Flown at 6500 MSL to = avoid=20 higher headwinds at higher altitudes and LOP (economy) to eliminate a = fuel=20 stop. Conditions were constant for the entire trip and all four data= =20 points are very similar. OAT 19C, Dalt 7500, KIAS 168, KTAS 187, 24.8" MAP,= 2480=20 RPM, 7.4 GPH and 24.5 DBTDC. Actual flight time was 4.3 hours an= d I=20 put 32.1 gallons at EDC having been left with a reserve of 9.9 gals.

EDC->PLK 440 NM 2.4 hours block to block. Flown at 9500 MSL t= o use=20 the winds and ROP (best power) to go fast. OAT 16C, Dalt 11000,= KIAS=20 163, KTAS 190 (Ahhh, over PGO GS 208 Kts), 22.1" MAP, 2490 RPM, 8= .5=20 GPH and 27 DBTDC.

PLK-> ARR 380 NM 2.2 hours block to block. Flown at 7500 MSL = and=20 ROP. OAT 18C, Dalt 8700, KIAS 171, KTAS 194, 24.1" MAP, 2500 RPM, 9.8= GPH=20 and 25 DBTDC.

Scott Krueger

IO 320, 9:1 CR, unfiltered ram air, dual Plasma III EI, Hart= zell=20 CS prop, uh, a few drag reducers....

In a message dated 11/26/2011 9:23:27 A.M. Central Standard Time,=20 casey.gary@yahoo.com writes:

=

Scott,

Thanks for the information. I took your numbers and did a crud= e=20 reqression analysis and came up with the following: The advance=20 increases by 2.2 degrees per thousand rpm above 1700 and 0.85 degrees per= =20 inche of manifold pressure below 28. Just gives a rough idea of how= it=20 works.

Gary

From Scott:

Restricting my comments to Lycoming engines (320, 360), one would no= te=20 that 25 DBTDC is the fixed timing delivered by standard magnetos and that= =20 timing is adequate for a wide range of engine operations. My injected 320= =20 engine has a 9:1 CR and uses a base timing of 20 DBTDC. Normal ROP cruise= =20 settings in the 4000 to 9000 MSL range and 2500 RPM (say 21 to 25 MAP), t= he=20 timing is between 24 and 26 DBTDC. At takeoff and low altitude race power= =20 settings (2760 -2600 RPM, WOT, 28-30 MAP), the timing is about 22-23 DBTD= C. At=20 leaned idle/taxi power (<10" MAP, <1100 RPM) the timing is about 34= -35=20 DBTDC. At altitudes 10000- 14000 MSL, 2500 RPM, WOT and LOP the timings a= re=20 generally 29-31 DBTDC.

Scott Krueger

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