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Mooney M20F climb and cruise settings


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I’m still on the fence on the best climb and cruise settings. My impression is full throttle on climb but pull rpm back to 26 then at cruise bring rpms back to 24. Thoughts?

 

ive also seen key numbers to equal to 48. @ 75%; 45 @ 65% and 42. @ 65% 

 

thoughts?...

 

lastly I have Gami injectors so I’ve been told to alway leant to LOP +50

 

additional thoughts...

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If I'm heavy I'll go WOT and 2700.  Otherwise, WOT and 2600 in the climb.  I'll lean above 5,000 DA to keep take-off EGTs.  Cruise is 8,000-10,000 feet at WOT and, usually, 2500 rpm.  I'll lean anywhere from peak (for speed) to 50 LOP (for low fuel burn).  Bad headwind I'll go 100 ROP (pretty rare I'll do this).

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2 hours ago, Htmlkid said:

 

 

ive also seen key numbers to equal to 48. @ 75%; 45 @ 65% and 42. @ 65% 

 

thoughts?...

 

lastly I have Gami injectors so I’ve been told to alway leant to LOP +50

 

additional thoughts...


Were these Key number related to your M20F?

Each model Mooney/engine gets its own key numbers...
 

LOP isn’t that rigid...
 

65% to avoid the red box...

How LOP, depends on CHTs...

Power drops off quickly as you go past 10°F LOP...

If you are flying at 10+k’ you probably won’t appreciate 50°F LOP when 1°F LOP will work...
 

If you get 50°F LOP at 10+k’, your GAMI spread is going to be very good...

Have you measured your GAMI spread?
 

Keep getting to know the system... LOP is really a great technique...

Best regards,

-a-

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3 hours ago, MikeOH said:

If I'm heavy I'll go WOT and 2700.  Otherwise, WOT and 2600 in the climb.  I'll lean above 5,000 DA to keep take-off EGTs.  Cruise is 8,000-10,000 feet at WOT and, usually, 2500 rpm.  I'll lean anywhere from peak (for speed) to 50 LOP (for low fuel burn).  Bad headwind I'll go 100 ROP (pretty rare I'll do this).

Just do this, you’ll be in good shape.  Although I’m impatient, so I’ll use his ROP setting more often than the LOP one.

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Only time I climb at 2600 is for noise reduction.
I start leaning after leaving the pattern, I lean for 150° ROP, best power that will keep cylinder temperatures below 400°.
I see no reason to go 50° LOP unless you’re trying to stretch the range, so normally 15° LOP.
I only ran ROP during engine break in flight, to keep cylinder temperatures below 420°.

To me it’s all about cylinder temperatures.

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I climb at 2700 until 1000 agl, then back to 2600 until reaching cruising altitude. I lean during the climb with a target of 100 ROP.  2500 and WOT for cruise.  Where I live at 4500 msl base elevation, I usually cruise between 8500 and 11500 feet.   At these altitudes it is hard to produce over 65% power, so I just use fuel flow rather than worry about how far lean of peak.  I have a Fuel Scan 450 and just pull back slowly to 9 gph for cruise.  

Edited by TTaylor
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Climb: Wide open throttle, prop full forward, continuously lean to maintain target EGT starting at 2000-3000' density altitude

Cruise: Depends on what you want to do. High/low/fast/slow. C152 fuel burn an putz around? Go fast? LOP? ROP? Red box?

Edited by Immelman
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Pretty much what everyone above says.  I will assume you're asking about cross country flights here and want to get the best performance possible with good efficiency...  Extended range legs or local "goofing off" flights will need different settings.

I like to climb at 120 IAS, WOT/2700 and cruise at WOT/2400 above 6k MSL.  On hotter days with heavier gross weights, climbs need to be at a higher IAS (128 is most efficient anyway, see Carson's Speed).

I do use power boost (unfiltered engine induction) when I'm above the highest visible haze layer (min 3k AGL, per the POH) and not around clouds, though not everyone is comfortable with that.  I won't argue with someone who recommends against its use.

Mixture is much more nuanced.  I highly recommend you read about the Red Fin to understand correct mixture settings better.  I usually run 15 to 35 LOP at about 63% to 73% power, though I've been known to use other settings (e.g., 75% 120 ROP when leg length isn't a concern).

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4 hours ago, afward said:

Pretty much what everyone above says.  I will assume you're asking about cross country flights here and want to get the best performance possible with good efficiency...  Extended range legs or local "goofing off" flights will need different settings.

I like to climb at 120 IAS, WOT/2700 and cruise at WOT/2400 above 6k MSL.  On hotter days with heavier gross weights, climbs need to be at a higher IAS (128 is most efficient anyway, see Carson's Speed).

I do use power boost (unfiltered engine induction) when I'm above the highest visible haze layer (min 3k AGL, per the POH) and not around clouds, though not everyone is comfortable with that.  I won't argue with someone who recommends against its use.

Mixture is much more nuanced.  I highly recommend you read about the Red Fin to understand correct mixture settings better.  I usually run 15 to 35 LOP at about 63% to 73% power, though I've been known to use other settings (e.g., 75% 120 ROP when leg length isn't a concern).

I’m pretty much in agreement with all your settings, but curious why you use 2400rpm cruise?  Especially LOP, that seems to give up a couple knots vs 2500 or even 2600 (only if I’m up pretty high/hot/heavy).

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Lots of very specific operations listed here. For take off I push all the knobby looking things all the way forward. I leave them there until my leanest EGT drops below 1200°. Then lean keep it between 1200 and 1300° for the rest of the climb. Once I get to altitude I unscrew the prop knob until the engine feels smooth (usually ~2550rpm). Then I lean the mixture based on my current goal (go fast, be efficient, be really efficient).

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1 hour ago, Ragsf15e said:

I’m pretty much in agreement with all your settings, but curious why you use 2400rpm cruise?  Especially LOP, that seems to give up a couple knots vs 2500 or even 2600 (only if I’m up pretty high/hot/heavy).

No compelling reason. It's a little quieter, and a little smoother. It's also slightly more efficient (MPG) and slightly less tach time for the same distance.

Mind you, conditions will easily nullify those last three, so there's that...

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interestingly, when you're set up in cruise, let everything stabilize at WOT, 2500 RPM, lean cruise. Then note the groundspeed, the ETA, and the EST fuel remaining from the JPI.  then pull the prop back to 2400.  dont touch nothing else. Wait 5 minutes. The FF comes down .2 and the airspeed drops by 3KT. 

Then look at all of the info again. Ive noticed on a 2 hour flight, it adds 3-4 minutes and saves .5 gallon of fuel.  So you spend $2.26 in extra airframe and component time (38$/hr) and save ~$2-$3 in fuel.  A wash at best. If you really need the gas to make the leg non stop, it saves you that, which is real.

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2 hours ago, jetdriven said:

interestingly, when you're set up in cruise, let everything stabilize at WOT, 2500 RPM, lean cruise. Then note the groundspeed, the ETA, and the EST fuel remaining from the JPI.  then pull the prop back to 2400.  dont touch nothing else. Wait 5 minutes. The FF comes down .2 and the airspeed drops by 3KT. 

Then look at all of the info again. Ive noticed on a 2 hour flight, it adds 3-4 minutes and saves .5 gallon of fuel.  So you spend $2.26 in extra airframe and component time (38$/hr) and save ~$2-$3 in fuel.  A wash at best. If you really need the gas to make the leg non stop, it saves you that, which is real.

Ive got 2 four year olds in the backseat, I’ll gladly take the 3-4 minutes!!:P

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