X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 26 Aug 2011 18:38:27 -0400 Message-ID: X-Original-Return-Path: Received: from smtp164.dfw.emailsrvr.com ([67.192.241.164] verified) by logan.com (CommuniGate Pro SMTP 5.4.1) with ESMTPS id 5104147 for lml@lancaironline.net; Thu, 25 Aug 2011 22:17:21 -0400 Received-SPF: none receiver=logan.com; client-ip=67.192.241.164; envelope-from=walter@advancedpilot.com Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp6.relay.dfw1a.emailsrvr.com (SMTP Server) with ESMTP id 7D529270441 for ; Thu, 25 Aug 2011 22:16:46 -0400 (EDT) X-Virus-Scanned: OK Received: by smtp6.relay.dfw1a.emailsrvr.com (Authenticated sender: walter-AT-advancedpilot.com) with ESMTPSA id 3C4352702B4 for ; Thu, 25 Aug 2011 22:16:46 -0400 (EDT) From: Walter Atkinson Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: multipart/alternative; boundary=Apple-Mail-5-1010356604 Subject: Re: [LML] LOP effect on CHT X-Original-Date: Thu, 25 Aug 2011 20:16:45 -0600 In-Reply-To: X-Original-To: "Lancair Mailing List" References: X-Original-Message-Id: X-Mailer: Apple Mail (2.1084) --Apple-Mail-5-1010356604 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Anything above about 230dF on the CHT is fine. Lycoming says 150dF. TCM = does not publish a number. Walter Atkinson On Aug 25, 2011, at 8:48 AM, Art Jensen wrote: It is true that running LOP will cause the engine to run cooler. As you = all know the Legacy doesn't have cowl flaps. I built my Legacy with = inlets in the cowl that are 1/4 inch smaller in diameter to reduce = cooling drag, tightened up the baffling to make use of all the cooling = air and I find that running LOP at altitude my CHT's will run from 278 = to 300 degrees. Since I could not find anything published regarding how = cool you can run the engine, I asked a tech rep. from Continental how = cool you can run the IO-550 engine and what damage would result should I = do so. He indicated that that's the reason you don't find a published = number. Is that possible? At the temps mentioned above, my oil temp is 180 degrees. So, I would like to hear from you regarding your thoughts on this = subject. Thanks for your input. Art Jensen From: Walter Atkinson ;=20 To: ;=20 Subject: [LML] Re: How do I run lean of peak?=20 Sent: Mon, Aug 22, 2011 5:28:42 PM=20 But what is your actual hourly saving and is it worth the additional = stress on your engines for the potentially much lower TBO? You decide = and your mileage may vary. 400 million hours of flight data supports the fact that when run ROP, = the TC-18 radial on the DC-7s had a TBO of 600 hours. When run LOP it = had a TBO of 3600 hours. Yep, 3 thousand 6 hundred vs. 6 hundred hours. --Apple-Mail-5-1010356604 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii

It is true that running = LOP will cause the engine to run cooler. As you all know the Legacy = doesn't have cowl flaps. I built my Legacy with inlets in the cowl that = are 1/4 inch smaller in diameter to reduce cooling drag, tightened up = the baffling to make use of all the cooling air and I find that running = LOP at altitude my CHT's will run from 278 to 300 degrees. Since I = could not find anything published regarding how cool you can run the = engine, I asked a tech rep. from Continental how cool you can run the = IO-550 engine and what damage would result should I do so. He indicated = that that's the reason you don't find a published number. Is that = possible?

At the temps mentioned above, my oil temp is 180 = degrees.

So, I would like to hear from you regarding your = thoughts on this subject. Thanks for your input.

Art = Jensen

From: Walter Atkinson <walter@advancedpilot.com>;=
To: <lml@lancaironline.net>; = =
Subject: [LML] Re: How do I run lean of peak? =
Sent: Mon, Aug 22, 2011 5:28:42 PM =

But what is your actual hourly = saving and is it worth the additional stress on your engines for the = potentially much lower TBO? You decide and your mileage may = vary.

400 = million hours of flight data supports the fact that when run ROP, = the TC-18 radial on the DC-7s had a TBO of 600 hours. When run LOP = it had a TBO of 3600 hours. Yep, 3 thousand 6 hundred vs. 6 = hundred hours.

= --Apple-Mail-5-1010356604--