M20E Speeds, EGT's and CHT's

[bill98]

What kind of CHT, EGT's and Cruise speeds do yall get up at elevation? What RPM setting do you use?

 

Mooney Zoom's with a tail wind and LOP - 8.6GPH

 

 

 

 

 

 

 

 

 

 

 

 

SAD HEADWIND

 

 

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[Hank]

Look up some of @Bob_Belville's panel porn and videos . . . . Fetch a drool rag first!

[lithium366]

I just bought my 66 M20E and got 138 kts at 2400 RPM / 21” (full throttle, poor man turbo) at 10500 when was delivering it. I have 3 blades prop. EGT 1380 / CHT around 320

[Bob_Belville]

I have decided my preference is full throttle, 2350 RPM, 7000-11,000' depending upon winds. At 8.0 gph LOP I see 145 ktas or a little less.

[RogueOne]

158knots at 7500’ 65%.  2600RPM FT/Ram Air Open burning 11.1GPH. 45gallons fuel on board.  330lb pilot/bags.

[Bob_Belville]

48 minutes ago, RogueOne said:

158knots at 7500’ 65%.  2600RPM FT/Ram Air Open burning 11.1GPH. 45gallons fuel on board.  330lb pilot/bags.

Rogue, where did you get the 65% figure? per vintage M20E Owners Manual, @ 7500', 2600 rpm, 23" MAP, standard atmosphere, is about 78%. And 11.1 gph would seem to be close to peak EGT since 12.8 is listed as best power. Did you note MAP?

 

[RogueOne]

26 minutes ago, Bob_Belville said:

Rogue, where did you get the 65% figure? per vintage M20E Owners Manual, @ 7500', 2600 rpm, 23" MAP, standard atmosphere, is about 78%. And 11.1 gph would seem to be close to peak EGT since 12.8 is listed as best power. Did you note MAP?

 

 

 

Edited June 21, 2019 by RogueOne

[Bob_Belville]

Rogue, you posted the 5000' page but that's not the issue. Your fuel flow at 11.1 is on the line for 2600 rpm and 19.5" MP. You would not be at 19.5 at 7500 and full throttle. At 23 or 24" MAP you're much higher than 65%, even at 11.1 gph.

To get to 65% at 7500'/23"/2600 you'd have to pull mixture back to 8.7 gph which would get you LOP.

[RogueOne]

My Owners Manual (as shown) does not provide (at 2600RPM) a 19.5”MP with 11.1 Fuel Flow.  I used the chart (Power) and fuel flow I wanted for balance between Mooney Power for MP indicated at altitude.  To be honest I did not record MP so could of been 23 or 80%?.  My fuel flow was comparable to the 80% at 11GPH.  That is my “Go fast” at altitude setting.  I slow down 9.4GPH and 2500RPM too sometimes.  A gallon and a half or $14 bucks in AVGas for increased speed over a couple of hours is worth it to me.  The second chart is theoretical as it is for IO360, but NOT specific to Mooney M20E.  I agree that there is a “discrepancy” regarding percent of power between Mooney and the theoretical.  I am at 7500’ so I can’t “hurt” the plane.  My cylinders are all happy as indicated during flight.  My plane gets over 10 knots from 9.5 to 11.0 (ground speed) and that is worth it to me as I am getting somewhere to do what I want to do when I get there.

[RogueOne]

5 minutes ago, Bob_Belville said:

Rogue, you posted the 5000' page but that's not the issue. Your fuel flow at 11.1 is on the line for 2600 rpm and 19.5" MP. You would not be at 19.5 at 7500 and full throttle. At 23 or 24" MAP you're much higher than 65%, even at 11.1 gph.

To get to 65% at 7500'/23"/2600 you'd have to pull mixture back to 8.7 gph which would get you LOP.

Fixed it.

[RogueOne]

9 minutes ago, Bob_Belville said:

Rogue, you posted the 5000' page but that's not the issue. Your fuel flow at 11.1 is on the line for 2600 rpm and 19.5" MP. You would not be at 19.5 at 7500 and full throttle. At 23 or 24" MAP you're much higher than 65%, even at 11.1 gph.

To get to 65% at 7500'/23"/2600 you'd have to pull mixture back to 8.7 gph which would get you LOP.

100% agree that power is more like 80% than 65% Bob.  Sorry for posting wrong page....bad eyes and small font   Mea Culpa...

[ArtVandelay]

What kind of CHT, EGT's and Cruise speeds do yall get up at elevation? What RPM setting do you use?
 

Is that paint overspray on the JPI and Aspen?


Tom

[Bob_Belville]

All good. My only comment related to the 65% power reference in your original post. FT/RAM air open would get you at least 23" MAP, probably 24" - Density Altitude, exhaust system design and conditions would effect.

Modern red box theory, John Deakin, Mike Busch, would say that you cannot hurt the engine at 65% or less, i.e. you can put the mixture anywhere you like. That's not the same as saying you can't harm the engine at 7500' or higher. Running at 2600 rpm you can pull 65% all the way to 10,000'   

But 158 ktas is nice. Almost as fast as the old Owners Manual promised! 

(FWIW, I have worked hard to make my '66E as fast as possible over the past 8 years. But I don't fly that way. I am planning to pick up my grandson to go to KOSH with a "little detour" coming home. The present flight plan is almost 6000 nm - NC-MA-WI-MN-ND-SD- MT-ID-NV-UT-WY-CO-NE-KS--MO-MA-NC. I will flight plan at FT, 2350 RPM, 8.0 gph and 145 ktas. @ 40 hours total each gph would add up to $200. i.e. 11 gph would add $600 to my fuel bill.)

To have a Mooney to brag about speed today takes an Acclaim. What our vintage Mooney does better than any other certified plane is efficiency. 145 knots on 8.0 gph is over 20 (s)mpg.

[RogueOne]

That will be an amazing trip.  Totally agree on the efficiency and speed of the vintage Mooney airframe.  Good points on the % power at altitude.  Engine is rated to TBO...Cylinders are happy...I am happy to have that extra speed.  Do NOT do it always, but sometimes?  Yes.  The best and ultimately most economical way to make a Mooney go faster is NOT mods...It’s fuel flow.  I fully understand the moditis.  I am also afflicted (to a degree)

You are fully “owned” by the “itis” and your plane is a tribute inside and out as you know.  I will just burn some gas and kick some...you know what...

Enjoy your wonderful trip Bob.

[RogueOne]

2 hours ago, Bob_Belville said:

All good. My only comment related to the 65% power reference in your original post. FT/RAM air open would get you at least 23" MAP, probably 24" - Density Altitude, exhaust system design and conditions would effect.

Modern red box theory, John Deakin, Mike Busch, would say that you cannot hurt the engine at 65% or less, i.e. you can put the mixture anywhere you like. That's not the same as saying you can't harm the engine at 7500' or higher. Running at 2600 rpm you can pull 65% all the way to 10,000'   

But 158 ktas is nice. Almost as fast as the old Owners Manual promised! 

(FWIW, I have worked hard to make my '66E as fast as possible over the past 8 years. But I don't fly that way. I am planning to pick up my grandson to go to KOSH with a "little detour" coming home. The present flight plan is almost 6000 nm - NC-MA-WI-MN-ND-SD- MT-ID-NV-UT-WY-CO-NE-KS--MO-MA-NC. I will flight plan at FT, 2350 RPM, 8.0 gph and 145 ktas. @ 40 hours total each gph would add up to $200. i.e. 11 gph would add $600 to my fuel bill.)

To have a Mooney to brag about speed today takes an Acclaim. What our vintage Mooney does better than any other certified plane is efficiency. 145 knots on 8.0 gph is over 20 (s)mpg.

Your 40 hour flight would be less than 40 with additional speed gained so would not be full $600 increase though, right?

[TTaylor]

1 hour ago, RogueOne said:

Your 40 hour flight would be less than 40 with additional speed gained so would not be full $600 increase though, right?

OK, back of the envelope calcs (ignoring climbs) and using estimates of 145 knots @ 8 gph and 155 knots @11 gph.

5800 nm  145 knot cruise, 40 hours, 320 gallons of fuel.

5800 nm  155 knot cruise, 37,4 hours, 411.6 gallons of fuel.

Saves 2.6 hours of flying and uses 91.6 more gallons of fuel.  About $100 savings on engine depending on how much per hour you estimate and $450 more in fuel for a net of about $350 extra to go faster.  If you plug in 10.5 gph rather than 11 gph it is 73 gallons extra.

Either way, time spent with grandson, priceless!

 

 

[Bob_Belville]

32 minutes ago, TTaylor said:

OK, back of the envelope calcs (ignoring climbs) and using estimates of 145 knots @ 8 gph and 155 knots @11 gph.

5800 nm  145 knot cruise, 40 hours, 320 gallons of fuel.

5800 nm  155 knot cruise, 37,4 hours, 411.6 gallons of fuel.

Saves 2.6 hours of flying and uses 91.6 more gallons of fuel.  About $100 savings on engine depending on how much per hour you estimate and $450 more in fuel for a net of about $350 extra to go faster.  If you plug in 10.5 gph rather than 11 gph it is 73 gallons extra.

Either way, time spent with grandson, priceless!

 

 

Yup. Engine depreciation is a factor but maybe not as much as the valuation formula might imply. 2350 vs 2600 probably means the lower setting results in fewer total revolutions even though the hours are higher. At the lower power setting the life of the engine should be greater. I would not be surprised to be able to go past TBO. An engine that's routinely run at 75% might not make TBO. 

I bought a factory new IO360 A1A for $10,000, installed, back in the '80s from a guy named Norm Bender. That engine is 6 times as expensive today. 

But hey, I understand loving to go fast... I flew my first M20E 50 years and 3000 hours ago.

[RogueOne]

We hope to fly for 4th (If weather ever cooperates). I will pop in all the MP and RPM settings and photograph the Groundspeed/ASI/Engine Monitor.  I have never done this.  Should be fun.  That way comparison of Cylinder/Exhaust Temps and fuel flow will be known.  How long at each setting do you think for temps on cylinders to stabilize?

Edited June 22, 2019 by RogueOne

[Pete M]

162 ktas at 10,500. Full throttle, 21", ram air open, 2550rpm, best power mix. No mods

Edited June 22, 2019 by Pete M

[Jerry 5TJ]

9 hours ago, Pete M said:

162 ktas at 10,500. Full throttle, 21", ram air open, 2550rpm, best power mix. No mods

162KTAS is 188 mph. At 10,500, 29.92” and 0C OAT that’s 137 KIAS, or 159 mph indicated?  That’s about what the POH calls for.  

My stock E was about 15 knots slower than book at 10,000’ and I flew it at that altitude frequently in California.  

Based on (LORAN!) ground speed averages of over 100 flights along the Manteca-Lake Hughes route at 9,000/10,000’ I typically got 142-145 KTAS.  

 

[HRM]

I got to Mach 0.38 once.

[MikeOH]

15 minutes ago, HRM said:

I got to Mach 0.38 once.

Did the controls reverse?