M20K cruise climbing advise

[manu damaschin]

I was wondering which is the best setting for climbing to altitude (mid tens) for M20K:

 

1. 40", 110-120 KIAS, aprox 1000 ft/min, 22-23 gal/h

 

2. 33", 110-120 KIAS, 500 ft/min, 18 gal/h

 

 

...does the first option reduce so much the engine life (full power), as it is more economical from the fuel point of view? What is your every day practice?

 

 

Thanks!

[231Pilot]

Much depends on which M20K you have and how it is equipped.  If you have a 231 with an intercooler, 40" is overboosting and will have a deleterious influence on engine life.  I would pay attention to the POH and to an supplements that might have been added with the installation of intercooler and/or upper deck limiter (automatic wastegate).  I have an intercooler but no upper deck limiter and I take off at 35", climb at 32".  Watch your CHT and TIT as you climb and adjust pitch and cowl flaps (along with MP) to keep temps in the appropriate range.

[FAST FLIGHT OPTIONS LLC]

#1 is the best way to do it and in my opinion the only way to climb in a 231 that hasn't been modified. There's no evidence that would suggest full power operations in an M20K reduce engine longevity. I think just the opposite is true as a climb at 120kts will keep cylinders cooler which could help extend engine life

[manu damaschin]

Much depends on which M20K you have and how it is equipped.  If you have a 231 with an intercooler, 40" is overboosting and will have a deleterious influence on engine life.  I would pay attention to the POH and to an supplements that might have been added with the installation of intercooler and/or upper deck limiter (automatic wastegate).  I have an intercooler but no upper deck limiter and I take off at 35", climb at 32".  Watch your CHT and TIT as you climb and adjust pitch and cowl flaps (along with MP) to keep temps in the appropriate range.

 

No aftermarket modifications to my 231...and the temperatures are just fine as long as ASI indicates 110-120...

[jlunseth]

I would take door three.  40", full rich which should be around 24 gph, and 500 fpm not 1000.  I am assuming you have a GB or LB with no intercooler and hence the 40".  That will keep the speed up so the engine gets cooling.  In my experience you will get the 1000 probably through the single digit thousands (i.e. 9,000) but somewhere above that depending on the day you will not get 1000 without a loss of airspeed and consequent loss of cooling.

[IndyTim]

This article is very good and I refer to it frequently for operational advice.  (Although I have an Encore - many principles still apply).

 

Full power to climb is advocated (but make sure you don't overboost the 231).  

 

http://www.mooneypilots.com/mapalog/M20K231%20Eval%20Files/M20K231_Eval.htm

[FAST FLIGHT OPTIONS LLC]

This article is very good and I refer to it frequently for operational advice. (Although I have an Encore - many principles still apply).

Full power to climb is advocated (but make sure you don't overboost the 231).

http://www.mooneypilots.com/mapalog/M20K231%20Eval%20Files/M20K231_Eval.htm

Seems like the author recommends cruise settings 50 degrees RoP which is quite possibly the worst place one could operate the engine on a 231.

[Z W]

I can only climb full power (36" for me) on cold days.  If it's warm outside, full throttle climb, even at 120 KIAS, will usually push the CHTs up past 380.

 

So I typically set power at 32" 2500 RPM and pitch for 500 FPM.  That yields about 110-120 KIAS, depending on weight, and CHTs of 380 or less, no matter what the outside temperature is.

 

If I'm solo, it's cold outside, and I'm headed to the teens to catch a tailwind, I'll leave it full throttle to get on up there.  But usually I'm heavy and its hot, so reduced power and 500 FPM keeps the engine happy.

 

I do always climb to at least 2,000 AGL before any power reduction in the climb out.  

 

Edit:  My point is, I don't think it matters how you do it, as long as you keep your engine temperatures cool.  Anything over 380 on the CHTs is bad for cylinder life.  As long as your temps are good, you aren't doing any damage to your engine, and the difference in fuel consumption is negligible.

[Dave Marten]

Climb 120 KIAS: 40" (36" intercooled) / 2700RPM / Full Rich / Cowl flaps open. Transitioning through 10K you should be able to partially close the cowl flaps. Hold the climb MP and 2700 RPM all the way to cruise altitude. At 120 KIAS you'll be optimizing efficiency (cooling and performance). Fly the airspeed not the VVI (you'll be easily exceeding 500fpm). Many will call the 120KIAS climb a cruise climb or Vz climb.