X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 30 May 2007 16:47:15 -0400 Message-ID: X-Original-Return-Path: Received: from [68.98.211.24] (HELO systems3.net) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2075167 for lml@lancaironline.net; Wed, 30 May 2007 14:07:37 -0400 Received-SPF: none receiver=logan.com; client-ip=68.98.211.24; envelope-from=cberland@systems3.net Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C7A2E5.5126C42C" X-MimeOLE: Produced By Microsoft Exchange V6.5 Subject: [LML] TSIO 550 LOP X-Original-Date: Wed, 30 May 2007 11:06:58 -0700 X-Original-Message-ID: <87C33F695961494D886EB3B6C8A476512F37A6@s3server.Systems3.local> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [LML] TSIO 550 LOP Thread-Index: Acei045xWzQTmXYXRyyIJCfwf8HsrAAAqG5w From: "Craig Berland" X-Original-To: "Lancair Mail List" This is a multi-part message in MIME format. ------_=_NextPart_001_01C7A2E5.5126C42C Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable OK, I started this discussion, so I will attempt to summarize with my opinion based on input I have received. Stated as opinion because I suspect the information I have received does not fall into the "laboratory data" category. =20 1. Do 8.5 CR engines go faster than 7.5 CR engines at the same fuel flow rate and LOP? To close to call, this is sorting the fly shit out of the pepper. =20 2. Will 8.5 CR reduce TIT when LOP and at the same fuel flow rate? Yes. Around 100 deg F. You then have two choices. Run lower TIT's or increase the fuel rate and go faster. The actual IAS seems to be more airplane or possibly instrument related than CR. =20 3. When TIT limited, 8.5 CR will allow fuel rate increases to produce approximately a 30 to 50 HP increase over 7.5 CR for identical TIT. These power increase numbers are a calculation based on .40 BSFC. At FL230 and up the many 7.5 CR engines have to run very LOP to control TIT, particularly if 1650 deg F is the limit. At these altitudes, some drivers choose ROP and this does affect the $'s per mile. There does seem to be a significant variance in TIT from airplane to airplane with the same CR. I wonder if this can be traced back to the intercoolers. If the manifold air temp goes up due to intercooler efficiency then the fuel rate must go down to maintain TIT. =20 Your mileage may vary. =20 Craig Berland ------_=_NextPart_001_01C7A2E5.5126C42C Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

OK, I=20 started this discussion, so I will attempt to summarize with my opinion = based on=20 input I have received. Stated as opinion because I suspect the = information=20 I have received does not fall into the "laboratory data"=20 category.

1. Do=20 8.5 CR engines go faster than 7.5 CR engines at the same fuel flow rate = and=20 LOP? To close to call, this is sorting the fly shit out of the=20 pepper.

2. Will 8.5 CR reduce TIT when LOP and at the same fuel = flow=20 rate? Yes. Around 100 deg F. You then have two = choices. Run=20 lower TIT's or increase the fuel rate and go faster. The actual=20 IAS seems to be more airplane or possibly instrument related than=20 CR.

3. When TIT limited, 8.5 CR will allow fuel rate = increases to=20 produce approximately a 30 to 50 HP increase over 7.5 CR for identical=20 TIT. These power increase numbers are a calculation based on .40=20 BSFC. At FL230 and up the many 7.5 CR engines have to run very LOP = to=20 control TIT, particularly if 1650 deg F is the limit. At these = altitudes,=20 some drivers choose ROP and this does affect the $'s per mile. = There does=20 seem to be a significant variance in TIT from airplane to airplane with = the same=20 CR. I wonder if this can be traced back to the intercoolers. = If the=20 manifold air temp goes up due to intercooler efficiency then the fuel = rate must=20 go down to maintain TIT.

Your=20 mileage may vary.

Craig=20 Berland

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