LOP operations

smalonesmalone
in General Discussion
I just had my O-540 engine in my Dakota overhauled and am about to undertake the break-in procedures. After those are complete I plan to explore the world of LOP operations. I have a JPI-700 analyzer sio I can monitor the CHT/EGT for each cylinder. There is even the ROP/LOP program on the JPI. I have been, up until now, using the 100 deg ROP out of fear of the LOP world. But with rising fuel costs I wonder if 2000 hours of LOP operation wount make a dent into my next OH expense. Any thoughts or suggestions?

Comments

  • JoeBJoeB
    About a decade ago John Deakin wrote a number of articles on engine operations and LOP operations in particular. They're embedded in his "Pelican's Perch" columns - and fairly easy to pick out by title:
    http://www.avweb.com/news/pelican/list.html

    The "Where Should I Run My Engine?" series (4 articles) is probably the best place to start. He discusses LOP with carburated engines in Part 3 (Cruise) of that series.

    One thing to keep in mind - Deakin's frame of reference is the turbo'd engine. Having an NA engine I've found that LOP isn't always the answer. Specifically, when up high the lower atmospheric pressure forces you to reduce fuel flow in order to stay LOP. In my aircraft, for example, I can maintain 75% power (15gph LOP) up to 7 thousand feet (depending on DA.) If I climb higher at the same fuel flow the engine goes over to the ROP side, so I have to reduce fuel flow to stay LOP. That reduces power output and the plane slows down. In effect we've found a "critical altitude" for LOP operation. At that altitude I switch over to ROP at Best Power (80 degrees ROP) and can get another couple thousand feet at good speed before the increasing altitude starves both pilot and airplane of air for good performance.
  • wiwarriorwiwarrior
    I may try to attend a 'leaning seminar' at Airventure if I can work it out with my time in position. I know there has been so much written & discussed about leaning methods. I do know at reduced power setting one can lean more aggressively that at higher settings, I take that into account. I also know every time I've checked fuel consumption in my 160 HP 0320 on longer trips I'm right near 7.25 GPH, 2400 RPM average.
  • TbugTbug
    A very interesting presentation on leaning:

    http://www.eaavideo.org/video.aspx?v=1678859198001
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