M20E vs M20J

[corn_flake]

Does any one have real life experience with M20E (short body) STC'ed with a M20J engine?  I'm interest in know the actual TAS with in this configuration.  Considering M20E is shorter and therefore lighter, wouldn't it out perform J?  

Thanks

[MBDiagMan]

As I understand, the J also has a 200HP Lycoming, so the difference would be somewhere between minimal and non existent.

Additionally, if you are talking about an unmodified E, the J would be faster due to the aerodynamic differences which are significant.

Edited January 4, 2022 by MBDiagMan

[EricJ]

There's not really much difference performance-wise between the two engines.   They're both Lycoming IO-360s with 200 hp.   The most significant differences are that the J has a dual mag and a dynamically-counter-weighted crankshaft, neither of which really affects performance as far as power output is concerned.   Were you maybe thinking of something else?

[corn_flake]

I'm trying figure out how J is able to achieve 175kt TAS in cruise while E with the same 200HP can only do 140kt TAS.  I know the J has slopped windshield.  But that surely can't account for nearly 35kt increase in speed, can it?  

 

[201Steve]

Who told you a J does 175 tas?

more like 155-160 tops. 

[KLRDMD]

4 minutes ago, corn_flake said:

I'm trying figure out how J is able to achieve 175kt TAS in cruise while E with the same 200HP can only do 140kt TAS.  I know the J has slopped windshield.  But that surely can't account for nearly 35kt increase in speed, can it?  

You aren't going to get 175 KTAS out of a J in the real world. Likewise, an E isn't as slow as you write. Real world, the E will be about a 150 KTAS airplane and the J will be 155 KTAS. A specific example of each will do a bit better or worse but those are pretty solid numbers for planning.

[201Steve]

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

[EricJ]

A J is an honest 150 kt airplane.   A stock E is an honest 145 kt airplane.    There are significant aero differences between the two.

 

[201er]

11 minutes ago, corn_flake said:

I'm trying figure out how J is able to achieve 175kt TAS in cruise while E with the same 200HP can only do 140kt TAS.  I know the J has slopped windshield.  But that surely can't account for nearly 35kt increase in speed, can it?  

175knots = 201mph

The whole 201mph thing is a best case scenario, brand new, clean, M20J at full power at sea level. That’s not a real world cruise speed.

And the speed difference comes from the cowl, not the engine. Windshield and inner gear doors help a little as well. 

Edited January 4, 2022 by 201er

[Mooney Dog]

1 hour ago, corn_flake said:

Does any one have real life experience with M20E (short body) STC'ed with a M20J engine?  I'm interest in know the actual TAS with in this configuration.  Considering M20E is shorter and therefore lighter, wouldn't it out perform J?  

Thanks

Given that the M20E is a IO-360-A1A at 200HP and that the J is a IO-360-A3B6D also at 200HP... 

 

i dont think there's gonna be much. 

 

1 minute ago, EricJ said:

A J is an honest 150 kt airplane.   A stock E is an honest 145 kt airplane.    There are significant aero differences between the two.

 

I hate you for this, but you are correct. 

[201Steve]

5 minutes ago, 201er said:

The whole 201mph thing is a best case scenario, brand new, clean, M20J at full power at sea level. That’s not a real world cruise speed

You forgot: with nose pointed over a lil bit

[DCarlton]

11 minutes ago, EricJ said:

A J is an honest 150 kt airplane.   A stock E is an honest 145 kt airplane.    There are significant aero differences between the two.

 

I've concluded after many flights between the same two airports, that my F with all the J mods is a 153 knot airplane (with a 3 blade prop).  So... I'll bet with all the speed mods including the cowl and windscreen and a two blade, you could get that or more out of an E.  I'm sure someone has done it.  

Edited January 4, 2022 by DCarlton

[Utah20Gflyer]

I heard at one point that they changed the amount of washout in the J wing which made it a little faster, ie an F with all the J mods will never be as fast as a J. Anyone know if this is true?  

[ArtVandelay]

Don’t forget the J has a better intake system making the ram air redundant, also muffler system is better as well. Personally I don’t run my engine like I stole it, so LOP/2500 gets me ~153knots burning 8-9 gph depending on altitude. I’m faster up north and slower down here in Florida…warmer air and higher humidity rob me of horsepower. I noticed I gain 5+ knots when I fly up north.
Under ideal conditions (cold, dry air) running ROP/2700 I think I would approach 170knots.
Es are lighter than Js….so if you have a need for speed, I suggest you lose weight…either yourself or the plane.

[corn_flake]

15 minutes ago, ArtVandelay said:

Under ideal conditions (cold, dry air) running ROP/2700 I think I would approach 170knots.

Since the consensus seem to suggest J can only do 160kt, if you get the chanceI would appreciate if you can share couple of pictures of your dash while doing 170kt.  No need for ground speed.  As we all known, ground speed for meaningless in this context.  It would help if you can have the altitude, pressure, and outside temperature to verify the ready as well. 

19 minutes ago, ArtVandelay said:

I suggest you lose weight…either yourself or the plane.

The truth hurts.... 

[Oliver]

We have a M20E with a few speed mods. We are getting around 150kts TAS @ 8,000 ft and 10 gal / hr.
I understand that a J would be only slightly faster, given the same conditions and fuel flow.

Where the E shines, though, is take off and climb performance, as the shorter body is lighter.

[Shiny moose]

I have a 67F twisted wing witha few mods 201 screen, flap gap seals, lower cowl closure, 3 bladed prop .I mostly cruise at 68% power shooting for 9-12K pending winds aloft and DA,  my normal TAS is 153-156 knots depending on weight of course. About book speeds for this old girl. No complaints

shes not very pretty but she make up for that with reliability and consistancy 

[takair]

11 hours ago, corn_flake said:

I'm trying figure out how J is able to achieve 175kt TAS in cruise while E with the same 200HP can only do 140kt TAS.  I know the J has slopped windshield.  But that surely can't account for nearly 35kt increase in speed, can it?  

 

Are you only seeing 140ktas in your E?

[201er]

7 hours ago, corn_flake said:

Since the consensus seem to suggest J can only do 160kt, if you get the chanceI would appreciate if you can share couple of pictures of your dash while doing 170kt.  No need for ground speed.  As we all known, ground speed for meaningless in this context.  It would help if you can have the altitude, pressure, and outside temperature to verify the ready as well. 

The truth hurts.... 

[DCarlton]

12 hours ago, bluehighwayflyer said:

No.  It’s not true.  At least not as stated.  In an apparently-misguided attempt to tame the M20’s stall characteristics Mooney experimented with washout a bit in/around 1967 and 1968 with F and G models.  Or thereabouts.  Once you know what you are looking at these “bent wing” Mooneys really stand out visually to the eye, but by all reports the “bent wing” had very little effect aerodynamically and it was quickly abandoned.  I don’t like they way they look, personally, but I really don’t think that there is anything wrong with them, and many if not most  F models don’t have the “bent wing”.   I don’t think that any C or E models that were built during the same time period had the “bent wing”, but I’m not 100% sure about that.  

As far as the speed differential between Es and J’s goes, in the real world, unmodified, it is probably on the order of 10 knots. Much more significant that that, though, between these two models are the J’s increased rear seat leg room and baggage room and increased fuel capacity.  

Interesting.  I've had my '67F with the twisted wing for around 18 years.  I'm aware of the twist but have never noticed a striking difference when compared with another Mooney.  I'm curious what you see now.  I'm going to look closer and compare when I get a chance.  I've always thought there could be a slight climb benefit with the twist as well but can't prove it.  

[Jerry Pressley]

did the twist wing have anything to do with the development of the Mustang?  that was the time of its development and it had it.

 

[corn_flake]

Any one have a picture of the twist wing Mooney?  

[Marauder]

But Captain, the dilithium crystals can’t take much more…

So, full out, you’re seeing 169. Does that gauge on your ASI subtract out the 2 to 3 CAS?

Also, taking a page out of Clarence’s notebook, why is your FP at the bottom of the green arc? And is your factory CHT INOP? That 830 isn’t certified for primary. Is the factory CHT required?


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[Marauder]

It’s always fun reading these threads. Like a bunch guys in a locker room comparing their manhood. The reality is that your accurate TAS will vary based on a bunch of different factors — even in an everything firewall forward situation.

> the accuracy of your ASI (if you’re using that method)
> the CAS correction
> whether your prop is really spinning at 2700
> parasite drag caused by something dragging (flaps, gear, etc.) or something in the breeze (antenna)
> whether your engine is actually able to produce full rated power
> your weight, your plane’s weight
> forward or aft CG
> the quality of your paint
> whether or not you are properly measuring it

So, with that. My 1975 F is a 200 knot airplane take 45 to 50 knots or so…


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[corn_flake]

@201er  So, it is possible for J to go 170kt!!  Thanks for sharing the picture!!