---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 08/19/19: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:05 AM - Re: Lycoming POH (Art Zemon) 2. 02:39 PM - Re: Bent EGT Probe Acceptable? (jdubner) 3. 03:00 PM - Re: Lycoming POH (Peter Pengilly) 4. 05:00 PM - Re: Lycoming POH (Kelly McMullen) ________________________________ Message 1 _____________________________________ Time: 05:05:22 AM PST US From: Art Zemon Subject: Re: AeroElectric-List: Lycoming POH Thanks for correcting my scrambled interpretation, Paul. Yet another reason why I am sticking to the simple method at 65% of leaning until I experience a loss of power and then enrichening until the engine runs smoothly again. I may not get the absolutely perfectly most optimal fuel flow but my engine seems healthy and I am happy with the gallons per hour (if not the $$$ per gallon). -- Art Z. On Sun, Aug 18, 2019 at 10:27 PM Paul Millner wrote: > Art Zemon wrflyote: > > Executive summary: > > =C2=B7 75% power or greater, run at peak EGT > > =C2=B7 less than 75% power, run up to 150 degrees F lean of peak > > > I think that's kind of scrambled, Art... the engine won't run 150 F lean > of peak. What the Lycoming POH refers to is 150 ROP as best power... > > Beyond that, running at peak EGT above 65% is not going to have good > results... > > > The wording of the POH is misleading, unfortunately. For instance, > Lycoming wrote: Maximum Power Cruise (approximately 75% power) =93 Never lean > beyond 150=C2=B0F on rich side of peak EGT unless aircraft operator's man ual > shows otherwise. > > So, which way is beyond, leaner or richer? What they mean is do not run > leaner than 150 ROP at 75% power or greater. But they do their best to > conceal that information. > > > If you refer to Lycoming SP700, "There are Experts Everywhere" Lycoming > explains that their engines can run just fine lean of peak. It's just tha t > Lycoming believes most pilots are too stupid to do so correctly, and so > they'll damage their engines... at least , that's what it says in SP700. > > > So the guidance intended, if we can puzzle our way through the byzantine > wording, is that 65% power or less, run anywhere you want, peak is a good > place. > > Above 65% power, run RICH enough or LEAN enough to keep CHTs below 380 F. > > > Paul, Talmudic service publication reader mode > -- https://CheerfulCurmudgeon.com/ *Love the stranger for you yourselves were strangers in Egypt. *Deut. 10:19 ________________________________ Message 2 _____________________________________ Time: 02:39:48 PM PST US Subject: AeroElectric-List: Re: Bent EGT Probe Acceptable? From: "jdubner" Thanks, Jerry. That's what I was thinking too although I have not heard of it being done. -------- RV-8A Independence, OR Read this topic online here: http://forums.matronics.com/viewtopic.php?p=490959#490959 ________________________________ Message 3 _____________________________________ Time: 03:00:23 PM PST US From: "Peter Pengilly" Subject: RE: AeroElectric-List: Lycoming POH I found the articles written by John Deakin in the =9CPelican=99s Perch=9D very informative, they used to be on AvWeb but I don=99t know if they are still there. They are written for large Continentals, but the concepts are valid on other engines. As Paul has said, above 75% power lean with care as it is possible to get into detonation which can be very poor for the health of your engine and you/your wallet. But above 6000ft most normally aspirated engines won=99t pull more than 75%. Below 75% I lean aggressively to reduce fuel burn =93 as I live in a land where gas is expensive ($8.50 a gallon =93 I really wish I hadn=99t done that sum) if I can save a gallon an hour it is attractive. I have found a fuel flow /rpm number where I am happy to leave the engine. It does take some experience with your particular installation to get to know what the numbers are. CHTs are cooler than running ROP for the same airspeed. It does take some care to run LOP safely, start up high in a low workload cruise so it is possible to monitor temperatures closely. Once you have some experience it is possible to run LOP nearly all the time once the initial climbing is done. Peter From: owner-aeroelectric-list-server@matronics.com On Behalf Of Art Zemon Sent: 19 August 2019 13:03 Subject: Re: AeroElectric-List: Lycoming POH Thanks for correcting my scrambled interpretation, Paul. Yet another reason why I am sticking to the simple method at 65% of leaning until I experience a loss of power and then enrichening until the engine runs smoothly again. I may not get the absolutely perfectly most optimal fuel flow but my engine seems healthy and I am happy with the gallons per hour (if not the $$$ per gallon). -- Art Z. On Sun, Aug 18, 2019 at 10:27 PM Paul Millner > wrote: Art Zemon wrflyote: Executive summary: * 75% power or greater, run at peak EGT * less than 75% power, run up to 150 degrees F lean of peak I think that's kind of scrambled, Art... the engine won't run 150 F lean of peak. What the Lycoming POH refers to is 150 ROP as best power... Beyond that, running at peak EGT above 65% is not going to have good results... The wording of the POH is misleading, unfortunately. For instance, Lycoming wrote: Maximum Power Cruise (approximately 75% power) =93 Never lean beyond 150=C2=B0F on rich side of peak EGT unless aircraft operator's manual shows otherwise. So, which way is beyond, leaner or richer? What they mean is do not run leaner than 150 ROP at 75% power or greater. But they do their best to conceal that information. If you refer to Lycoming SP700, "There are Experts Everywhere" Lycoming explains that their engines can run just fine lean of peak. It's just that Lycoming believes most pilots are too stupid to do so correctly, and so they'll damage their engines... at least , that's what it says in SP700. So the guidance intended, if we can puzzle our way through the byzantine wording, is that 65% power or less, run anywhere you want, peak is a good place. Above 65% power, run RICH enough or LEAN enough to keep CHTs below 380 F. Paul, Talmudic service publication reader mode -- https://CheerfulCurmudgeon.com/ Love the stranger for you yourselves were strangers in Egypt. Deut. 10:19 ________________________________ Message 4 _____________________________________ Time: 05:00:28 PM PST US Subject: Re: AeroElectric-List: Lycoming POH From: Kelly McMullen The articles have been moved a time or two. I believe this is still a good link: https://web.archive.org/web/20120119070724/http://www.avweb.com/news/pelican/list.html On 8/19/2019 2:58 PM, Peter Pengilly wrote: > I found the articles written by John Deakin in the Pelicans Perch > very informative, they used to be on AvWeb but I dont know if they are > still there. They are written for large Continentals, but the concepts > are valid on other engines. As Paul has said, above 75% power lean with > care as it is possible to get into detonation which can be very poor for > the health of your engine and you/your wallet. But above 6000ft most > normally aspirated engines wont pull more than 75%. > > Below 75% I lean aggressively to reduce fuel burn as I live in a land > where gas is expensive ($8.50 a gallon I really wish I hadnt done > that sum) if I can save a gallon an hour it is attractive. I have found > a fuel flow /rpm number where I am happy to leave the engine. It does > take some experience with your particular installation to get to know > what the numbers are. CHTs are cooler than running ROP for the same > airspeed. It does take some care to run LOP safely, start up high in a > low workload cruise so it is possible to monitor temperatures closely. > Once you have some experience it is possible to run LOP nearly all the > time once the initial climbing is done. > > Peter > > *From:*owner-aeroelectric-list-server@matronics.com > *On Behalf Of *Art Zemon > *Sent:* 19 August 2019 13:03 > *To:* aeroelectric-list@matronics.com > *Subject:* Re: AeroElectric-List: Lycoming POH > > Thanks for correcting my scrambled interpretation, Paul. Yet another > reason why I am sticking to the simple method at 65% of leaning until I > experience a loss of power and then enrichening until the engine runs > smoothly again. I may not get the absolutely perfectly most optimal fuel > flow but my engine seems healthy and I am happy with the gallons per > hour (if not the $$$ per gallon). > > -- Art Z. > > On Sun, Aug 18, 2019 at 10:27 PM Paul Millner > wrote: > > Art Zemon wrflyote: > > Executive summary: > > 75% power or greater, run at peak EGT > > less than 75% power, run up to 150 degrees F lean of peak > > I think that's kind of scrambled, Art... the engine won't run 150 F > lean of peak. What the Lycoming POH refers to is 150 ROP as best > power... > > Beyond that, running at peak EGT above 65% is not going to have good > results... > > The wording of the POH is misleading, unfortunately. For instance, > Lycoming wrote: Maximum Power Cruise (approximately 75% power) > Never lean beyond 150F on rich side of peak EGT unless aircraft > operator's manual shows otherwise. > > So, which way is beyond, leaner or richer? What they mean is do not > run leaner than 150 ROP at 75% power or greater. But they do their > best to conceal that information. > > If you refer to Lycoming SP700, "There are Experts Everywhere" > Lycoming explains that their engines can run just fine lean of peak. > It's just that Lycoming believes most pilots are too stupid to do so > correctly, and so they'll damage their engines... at least , that's > what it says in SP700. > > So the guidance intended, if we can puzzle our way through the > byzantine wording, is that 65% power or less, run anywhere you want, > peak is a good place. > > Above 65% power, run RICH enough or LEAN enough to keep CHTs below > 380 F. > > Paul, Talmudic service publication reader mode > > > -- > > https://CheerfulCurmudgeon.com/ > > /Love the stranger for you yourselves were strangers in Egypt. /Deut. 10:19 > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.