Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: Leaning methods

  1. #1
    Member
    Join Date
    May 2011
    Location
    Mission Beach, Qld, Australia
    Posts
    39

    Default Leaning methods

    Interested in members opinions in leaning techniques, LOP or ROP, for the 180? I have EGTís and CHTís on all cylinders, so can do either, but I am reluctant to try lean of peak on a carbureted engine. That said, I know very little of the pros and cons, and I certainly do not want to risk engine damage.

  2. #2
    Senior Member Centmont's Avatar
    Join Date
    Jan 2010
    Location
    Winifred, Montana
    Posts
    257

    Default Re: Leaning methods

    Opinion here: In a perfect world where every cylinder got exactly the same temp and volume of cooling air...and where the air gas mix was the same in each...LOP is an option. We don't live in that world. If your goal, as stated, "certainly do not want to risk engine damage"... then I would recommend ROP... at least at low altitudes. If you are sipping fuel up at 10,000 plus...LOP is "probably" safer...but then, that isn't where we were designed to fly. Enjoy that bird..amazing fun. Ralph
    Ralph Rogers
    Owner: TheCubWorks
    www.TheCubWorks.com
    CCSS #142 N123MR
    I have always felt the supercub is one thing mankind got right the first time but that there were better materials and methods to build them. CubCrafters products are proof I was right.

  3. #3
    Senior Member
    Join Date
    Sep 2011
    Location
    Rowe, NM; St. George Island, FL; Montgomery, AL
    Posts
    123

    Default Re: Leaning methods

    I would suggest a couple of points:

    1. As long as your power is less than 65% (and last I looked, 80 hp is less than 65% of 185 hp you cannot hurt an engine with LOP operations.
    2. Carburated engines are far more difficult to make work well LOP...but some say if you just put in a tad of carb heat, the turbulence helps.
    3. Aggressive leaning will not hurt an engine (especially <65%) as long as your CHT's stay reasonable...even over <65%.

    This all comes from the APS course...those guys know their stuff.

    Jim

  4. #4
    Senior Member randylervold's Avatar
    Join Date
    Jan 2010
    Location
    Yakima, WA
    Posts
    1,378

    Default Re: Leaning methods

    Quote Originally Posted by Jim Harper View Post
    I would suggest a couple of points:

    1. As long as your power is less than 65% (and last I looked, 80 hp is less than 65% of 185 hp you cannot hurt an engine with LOP operations.
    2. Carburated engines are far more difficult to make work well LOP...but some say if you just put in a tad of carb heat, the turbulence helps.
    3. Aggressive leaning will not hurt an engine (especially <65%) as long as your CHT's stay reasonable...even over <65%.

    This all comes from the APS course...those guys know their stuff.

    Jim
    Ditto Jim's comments.
    Randy Lervold

  5. #5
    Member armaurer's Avatar
    Join Date
    Sep 2011
    Location
    Sarasota, FL
    Posts
    52

    Default Re: Leaning methods

    Quote Originally Posted by pwill435 View Post
    Interested in members opinions in leaning techniques, LOP or ROP, for the 180? I have EGTís and CHTís on all cylinders, so can do either, but I am reluctant to try lean of peak on a carbureted engine. That said, I know very little of the pros and cons, and I certainly do not want to risk engine damage.
    Living in Florida it is usually warm and at our low altitudes and the fact that the cylinder heads tend to run hot,
    I usually run full rich to not go over 400 on the cylinder heads. it is my understanding that CC will redesign
    the plenum and cowling for better cooling and this will be available perhaps in the next year/
    Hopefully it will be available as a retrofit.
    Alan
    Alan Maurer
    Carbon Cub #183
    Sarasota, FL

  6. #6
    Member rlinford's Avatar
    Join Date
    May 2010
    Location
    Spokane, WA
    Posts
    42

    Default Re: Leaning methods

    In my T206 with fuel injection it was worth doing because it burned 21gph at 75% 75deg ROP and with balanced injectors LOP worked pretty well and I took it down to about 18 which saved $15 an hour. In a 4 cylinder normally aspirated engine running LOP without huge variations in CH and EXH temp is pretty tough. Way LOP is fine as mentioned below but ask yourself if the money saved over 1500 hours flight time is worth risking a $10k overhaul or worse. I doubt you will be saving more than $5 an hour. Personally I would not bother with LOP unless I was running a larg thirsty fuel injected engine with calibrated gauges on each cylinder.

  7. #7
    Junior Member
    Join Date
    Jul 2012
    Location
    Washington
    Posts
    18

    Default Re: Leaning methods

    Remember, peak CHT will occur 50-150 degrees ROP on the EGT. Lean beyond that and CHTs will start dropping. And you'll also be reducing power the whole time as a result. Carbureted engines generally cannot run LOP because of the different fuel/air mixtures in each cylinder. You basically have 4 1-cylinder engines flying in formation. That's why you get roughness when you lean because each cylinder is making different power at that point and these different powers are being transmitted to the crank.

    Read this:
    http://www.avweb.com/news/pelican/182084-1.html

  8. #8
    Member
    Join Date
    May 2011
    Location
    Mission Beach, Qld, Australia
    Posts
    39

    Default Re: Leaning methods

    I have installed a fuel flow, and EGT and CHT on each cylinder. Still working out how to use them, but what I have immediately found is about 25 Ė 30% reduction in fuel flow when I simply lean off to rough running, then richen back 4 notches. This is in cruise at 2150 RPM at 1000ft, 25degC OAT. Obviously this rather crude old method is very easy, and I wonder whether it isreally worth doing anything more sophisticated? Also, does this method put you LOP or ROP?
    Paul.

  9. #9
    Junior Member
    Join Date
    Jul 2012
    Location
    Washington
    Posts
    18

    Default Re: Leaning methods

    Quote Originally Posted by pwill435 View Post
    i have installed a fuel flow, and egt and cht on each cylinder. Still working out how to use them, but what i have immediately found is about 25 Ė 30% reduction in fuel flow when i simply lean off to rough running, then richen back 4 notches. This is in cruise at 2150 rpm at 1000ft, 25degc oat. Obviously this rather crude old method is very easy, and i wonder whether it isreally worth doing anything more sophisticated? Also, does this method put you lop or rop?
    Paul.

    --rop

  10. #10
    Member
    Join Date
    May 2011
    Location
    Mission Beach, Qld, Australia
    Posts
    39

    Default Re: Leaning methods

    Thanks Nathanial. So does that settle the discussion regarding LOP on carbureted engines, since if I adjust any leaner it would cause rough running.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •