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M20E vs M20J


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These are perfomance pages form the 67F and an older J , maybe they needed to get rid of the twisted wing F do to its stated highest TAS book performance. Yes the power on the F is up, but still same TAS, cant sell a airplane as the fastest when you already had one that would do it.

 

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5BA4FD9C-E62F-4E8F-88FD-7DF4AD9986EF.jpeg

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My '64 E did 162ktas at 10k. Verified with two seperate 4 way gps runs. One at about 8500ft and the other at about 10.5. 200lb pilot, maybe 60% fuel. No mods to speak of. Ram open, full throttle, 2550 on the prop. Recent overhaul, new prop, fresh paint over sanding primer. When I bought it, it was probably a 145kt airplane.  The little things do make a difference.

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On 1/4/2022 at 8:42 PM, MMsuper21 said:

The M20E has a Vne of 189mph (165kts). I think you will be pushing your luck trying to cruise at 170kts. I think with all the speed mods its possible. I routinely cruise around 150kts+. I will need to take some pics of the ASI it’s based off gps. I have the cowl enclosure and one piece non 201 windshield and possibly some other speed mods I am not aware of. 

Besides the extra rear leg room the J has higher Vne, Vfe and and Vlo speeds.  It like people tuning their cars doubling the hp and not upgrading their brakes. 

You're confusing indicated with true airspeed.

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  • 2 weeks later...
On 1/3/2022 at 8:58 PM, 201Steve said:

There is a guy around here with a turbo E and all the J mods. Says he gets around 170 as I recall. 

My E is normalized with all J mods except cowl closure instead of 201 cowl.  It was a 145 knot bird before and 165 now at 8000 ft, and during the re rig it was plenty out of spec, so a few knots in the rig.  Also, I run 27 inches 2400 rpm 10 gph LOP which is a true 75 percent and might be a few knots better than 2500 wide open ram air at 8000 ft.  So, maybe 15 knots less drag on a J.  A J is also longer and heavier and I think trim drag is a bit worse.

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10 hours ago, 65eTurbo said:

My E is normalized with all J mods except cowl closure instead of 201 cowl.  It was a 145 knot bird before and 165 now at 8000 ft, and during the re rig it was plenty out of spec, so a few knots in the rig.  Also, I run 27 inches 2400 rpm 10 gph LOP which is a true 75 percent and might be a few knots better than 2500 wide open ram air at 8000 ft.  So, maybe 15 knots less drag on a J.  A J is also longer and heavier and I think trim drag is a bit worse.

How do you get 27" of MP at 8000ft? Even with the 1" boost the Ram Air gives me, I don't think I can produce anywhere near that power in my E at full throttle. Usually I believe MP starts dropping at full throttle around 5-6000 ft, by 8000 I'm probably at around 22".

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Just now, jacenbourne said:

How do you get 27" of MP at 8000ft? Even with the 1" boost the Ram Air gives me, I don't think I can produce anywhere near that power in my E at full throttle. Usually I believe MP starts dropping at full throttle around 5-6000 ft, by 8000 I'm probably at around 22".

He is turbo normalized.

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10 hours ago, 65eTurbo said:

My E is normalized with all J mods except cowl closure instead of 201 cowl.  It was a 145 knot bird before and 165 now at 8000 ft, and during the re rig it was plenty out of spec, so a few knots in the rig.  Also, I run 27 inches 2400 rpm 10 gph LOP which is a true 75 percent and might be a few knots better than 2500 wide open ram air at 8000 ft.  So, maybe 15 knots less drag on a J.  A J is also longer and heavier and I think trim drag is a bit worse.

I don’t have the charts for turbo normalized, but extrapolation seems to tell me that 27” at 2400 would be over 75%?  I don’t doubt the speed at that setting, but the % power seems off.

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4 minutes ago, takair said:

I don’t have the charts for turbo normalized, but extrapolation seems to tell me that 27” at 2400 would be over 75%?  I don’t doubt the speed at that setting, but the % power seems off.

That’s the recommended setting from rajay turbos keep mp at 27 and rpm 2500. 

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20 hours ago, MMsuper21 said:

That’s the recommended setting from rajay turbos keep mp at 27 and rpm 2500. 

Interesting. Goes to show how robust these engines are. I always assumed that the normalized meant same power settings at higher altitude, but this tells me that it I higher power setting than we might normally run, even down low. 

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38 minutes ago, takair said:

Interesting. Goes to show how robust these engines are. I always assumed that the normalized meant same power settings at higher altitude, but this tells me that it I higher power setting than we might normally run, even down low. 

Turbo pushes MP above standard sea level. Turbonormalizing let's you run up to sea level MP to some higher altitude, often in the teens. If I understand it correctly, not having owned either one. :P

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On 1/21/2022 at 9:59 AM, takair said:

I don’t have the charts for turbo normalized, but extrapolation seems to tell me that 27” at 2400 would be over 75%?  I don’t doubt the speed at that setting, but the % power seems off.

I tun 10 gph LOP.  When LOP for an IO 360 compression ratio, hp equal 14.7 time gph.  10 gph is 147 hp or 73.5 percent...

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21 hours ago, M20F-1968 said:

27" MP gets me more than 75% power.  

Set MP and prop for 75% HP or less, then lean as per engine monitor.

I do not see why you need to be married to 24" 2400 RPM?

John Breda

John,

 Even if you don't buy let 10 gallons per hour while LOP is 73.5 percent for our engines, our engines are rated for 100 percent continous power.  So, make sure you are within Turbo system limits and you can run any MP you want.  When LOP, 10.gph is 73.5 percent.

 

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13 hours ago, asaxet said:

1966 m20e with windshield, flap and aileron gap seals, flap hinge fairings, overlap nlg doors, chin cowl and speed brakes from lazar.... 

 

flat out 13.5 gph will do 172kts.....  usually cruze 160kt  on 11.5gph.....   55 deg oat....  2k feet msl  gotta love the E's crushing the yellow...  great little birds....

 

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Both your mechanical ASI and the Aspen show you running above recline . . . .

Where the yellow ends,the red line sits. You are past it, that's why the Aspen has airspeed number in red and the pointer well into the barber pole section. 

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50 minutes ago, Hank said:

Both your mechanical ASI and the Aspen show you running above recline . . . .

Where the yellow ends,the red line sits. You are past it, that's why the Aspen has airspeed number in red and the pointer well into the barber pole section. 

That's the sort of pic that shows up later on a Kathryn's report page or something.

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On 1/5/2022 at 5:53 PM, TStepp said:

FWIW - from a recent speed run in our 67 M20F:

Configuration:
67 M20F S/N 67-0204
Lycoming IO-360-A1A, 950 hrs. since remanufactured
2-blade Hartzell prop, SWTA cowl / windshield / spinner, LASAR speed fairing mods (wing and tail roots, dorsal fin, etc.), Brake Wheel Cylinder Rotation, no inner gear doors
~500 lbs below MGW (~2250)

Conditions:
High pressure system over San Diego area, stable air mass (inversion layer)
7,500 MSL, 16 deg. C OAT (5 deg. C on the ground)
22" MP (ram air open), 2600 RPM, 100 deg. ROP, 12.3 GPH

Result (derived from 4x GPS ground speed velocity vectors):  153 kts

 

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My ‘67 F with all J modifications is very consistent with these numbers.

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