My two favorite settings...

[211º]

I've found my two favorite "set it and forget it" settings in my Mooney.

21/2350: When I want to go far without stopping for gas or have a huge headwind and regardless of altitude, I "set it and forget it" at 21"/2350 RPM/7gph.  This gives me a comfortable endurance of 5.5 hours (mathematically around 7 hrs - but 5.5 with reserves), set my watch for 1hr 40 min to change tanks and and IAS of 130 mph.

22/2400: When I want to go faster and stay just outside of the yellow - around 5,000 to 6000', 22"/2400 RPM/~10 gph, a comfortable endurance of 3.5 hours, a watch setting of 1 hr, and about 147mph indicated gives me a no-wind of about 162mph over the ground.

Do others have one, two or three favorite settings?

[Hank]

I pretty much use three, which are altitude dependent:

• Low level, short trips / flightseeing--23" / 2300 for 3000 msl and below
• Mid-level medium trips (~1 hr, up to ~6500 msl)--22" / 2400
• Longer trips, 7500 msl and up--WOT- / 2500 (back off WOT just enough to budge the MP needle, to close off the enrichment circuit in the carb). Generally 145-148 KTAS.

M20-C, in case you miss my avatar / signature. I run 50 Rich, except up.high I may be closer to peak. 

Edited December 24, 2020 by Hank

[FlySafe]

These are mine in a 74 C model, 0-360-A1D, at 6-8K, with JPI830 leaned for peak EGT. The 1st combo is my go to setting

21/23, key #44, ~55%HP, ~135kt TAS, 8.5gph.... Carson speed for the C model (~1.3 x Vg)

22/23, key #45, ~65%HP, ~140kt TAS, 9.0gph

23/23, key #46, ~75%HP, ~145kt TAS, 10.0gph

Edited December 25, 2020 by FlySafe
added engine make and speed units

[Browncbr1]

23/23 peak low

22/24 peak high

io-360-a1a

 

[jaylw314]

For trips >30 min or with passengers:

• WOT/2500 RPM 5-10k' MSL
• WOT/2650 RPM above 10k' MSL
• for sightseeing or puttering around, I'll use 21"/2000 RPM

For shorter trips and by myself, I actually enjoy randomly picking a new combination

[EricJ]

WOT/2500 if not in takeoff or climb or slowing for landing.

 

[201er]

120KIAS all flight long
 

Set for whatever makes the max KTAS at 120KIAS for best bang for the buck speed all flight long. WOT the entire cruise and climb. 2700RPM in the climb, pitch for 120KIAS, lean for target EGT ROP. Cruise, RPM down for 120KIAS and lean to 8gph LOP. Descent, 300fpm, reduce power as needed to maintain 120KIAS LOP. Power as needed to land. Generally 2200/22 6.5GPH LOP on downwind.

Simple, predictable, fast, and efficient.

I can fly all day like this and make it across most of the country without a stop.

[211º]

@Hank and @201er, I think that you two were one ones who inspired me to look at power settings by altitude and "fly forever at LOP", respectively.  I quite appreciate those lessons.

I think that I'll now begin looking at 2500 above (say) 7,000 feet - I think that I've tried that before, but it seems like 61Q prefers (sounds better?) at 2400.

As I thinking yesterday, I was a little surprised that 21/2350 and 22/2400 provide about 17 mph ias difference, but now that I think about it more, it is also a LOP vs. ROP difference.

I may start setting power on trips by anticipated flight time too: 3 hrs or less = 22/2400/10gph; more than 3 hrs = 21/2350/7.0gph.

[0TreeLemur]

On 12/27/2020 at 6:27 AM, 211º said:

I think that I'll now begin looking at 2500 above (say) 7,000 feet - I think that I've tried that before, but it seems like 61Q prefers (sounds better?) at 2400.

My a/c also seems to like 2400 rpm compared to 2500, especially below about 8k.  It's "calmer", with little difference in GPS indicated GS at the same MP.  I cruise at 73-75% power and 2400 rpm down low using the JPI 900.  Above about 5k, it is WOT but closed just enough to minimize onset of roughness while leaning and 2400 rpm.   Following what Mike Busch wrote in "Engines", I run my carbureted beast 100-120F ROP.