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Dakota O-540 Engine Procedures - Do I need an engine monitor?

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PA-28-236 Dakota
Supporting Member
Jul 30, 2022
Reaction score
Hello Everyone,
after ~50h in the first year of Dakota ownership, I am hoping for feedback on my engine procedures and also wonder if I should invest in an engine monitor.
  • Carbureted O-540-J3A5D with 120 SMOH - so practically new.
  • Original 1983 factory instrument panel - so just ONE EGT, OIL TEMP, OIL PRESSURE, NO CHT, NO FUEL FLOW
How I operate:
  • The engine typically starts after 3-5 revolutions. I do pump the throttle 2-3x times before cranking. Practically never use the primer.
  • I aggressively lean: Both, on ground and in the air. The only phases mixture is full forward, is from run-up to 2000FT AGL and during approach & landing
  • I slightly pull prop and mixture at 2000FT AGL to 2300 RPM and until I see EGT coming alive - I found that this gives me plenty of power to climb (800ft/min @ 90KT IAS)
  • The POH says to fly at PEAK EGT - I find this hard to accept. I try to lean until EGT slightly moves down again but found this only working well at WOT.
  • I operate WOT most of the time while in flight. Typically I fly at 5000-10000FT with 2100 RPM, leaned to slightly above engine roughness can be felt. This gives me about 100-110 KT IAS, which is OK for me. Pushing mixture forward increases engine power significantly. I take this as a sign of being LOP. There seems to be no practical limit for running oversquare (see attached Lycoming Chart)
  • Sometimes when it's really only about low level sight seeing, I fly at 1900-2000 RPM and pull the throttle a good bit. In this case EGT goes up quickly as soon as I pull the throttle. At this RPM, OIL pressure gets very close to lower limit of the green arch.
  • Long time average is about 11.9GAL/h (45l/h) - hours only counted when in the air - so this average includes one run-up and taxiing as I average roughly 1flight/1h.
Without CHT and Fuel Flow, I sometimes find it hard to have a good understanding of the engine status. I do watch OIL temps closely. But never found it to be particularly high. It only really ever moves up when going up from 0 to 10.000ft in one go, fully loaded.

Engine Monitor:
  • I do like the original panel and I am not planning to upgrade it any time soon - but from the moment I bought the plane, I was thinking about an Engine Monitor, both for safety and for maxing out engine economy.
  • Now after 50h my feeling/believe is, that this engine is so overpowered/derated, that I can't really do anything that would break it and therefore an engine monitor would be nice, but would not change much. On the other hand the safety factor of knowing that there is something going wrong, would be nice.
Keen to hear your thoughts! Both on my procedures and on the engine monitor.


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