Modded F versus J

[rturbett]

What other differences are there between an F that is full of the speed mods- ie one pc belly, seals, windshield, and a factory production J?

Thanks,

Rob

[Andy95W]

The cowling.

Turns out, the old cowling is not only worse for cooling, but contributes a ton of drag that the J cowling doesn’t.

[Niko182]

You also don't have the new style interior that the Post 82 J's have, such as folding independent rear seats. Newer J's also had fiberglass interiors.

[ArtVandelay]

77 was a transition year.
78 got rid of the throttle quadrant, going to push pull controls, increased Vle.
ALL: Improved engine intake, making the ram air superfluous (was removed in later years). Annunciator.

The interior changes and other changes started to add weight, in 87 they increased the maximum weight to 2900 lbs.

From performance perspective, the engine intake was the big difference, the assorted 205 speed modifications only increased top speed by 4 mph above the 201.

[rturbett]

Thank you!

[Shadrach]

On 8/9/2023 at 11:35 PM, Niko182 said:

You also don't have the new style interior that the Post 82 J's have, such as folding independent rear seats. Newer J's also had fiberglass interiors.

In 1967 F models came stock with removable, split folding rear seat backs that would articulate fully forward. This allows for the transport of  all sorts of bulky items the would otherwise not be possible. Mine has carried a full size road bike and the prop from a Comanche 250 just to name a few.

[Shadrach]

8 hours ago, rturbett said:

What other differences are there between an F that is full of the speed mods- ie one pc belly, seals, windshield, and a factory production J?

Thanks,

Rob

 A lot of that stuff adds weight and bragging rights but little else. The cowl and windshield are worthwhile for styling alone. The one piece belly ads weight (~15lbs) for the convenience of easier removal.
 

The speed differences between the 200hp machines is sometimes exaggerated as much as the top speeds. Block speeds between the two is likely well under 10kts.

Differences in weight should be considered depending on mission. Newer and modified planes weigh more than the older planes. I looked at several Js on trade a plane. The ones that listed UL had between 100lbs and 219lbs less useful load than my 67F model. 

 

 

 

[slowflyin]

I would guess an F with J cowling and WS would have a higher UL but lack some of the interior refinements.   

[A64Pilot]

Does the F have the J’s induction and exhaust?

The exhaust in particular impresses me, aircraft exhausts performance wise are usually junk, but the J’s isn’t.

[Vance Harral]

26 minutes ago, slowflyin said:

I would guess an F with J cowling and WS would have a higher UL but lack some of the interior refinements.  

Depends on what year models you're talking about.  The instrument panel, controls, and interior of a 1976 M20F are identical to that of a 1977 M20J.  So much so that if you happen to have the former, you actually need the M20J parts and service manual to understand some of the interior assemblies.  Not that this makes a major difference, just interesting trivia.

[201er]

12 hours ago, rturbett said:

What other differences are there between an F that is full of the speed mods- ie one pc belly, seals, windshield, and a factory production J?

Thanks,

Rob

Vne, yellow arc, gear extension speeds all increased on J. That's one thing no amount of mods can recoup even if it's made to look the same.

 

Also I think the A3B6D makes slightly better real world performance than the A1A with the 25BTDC timing despite both being labeled 200HP.

Edited August 10, 2023 by 201er

[MisfitSELF]

12 hours ago, rturbett said:

What other differences are there between an F that is full of the speed mods- ie one pc belly, seals, windshield, and a factory production J?

Thanks,

Rob

I shopped for years to find that "unicorn" 1967 M20F with the Johnson bar and "all the 201 mods" -- low engine time and usable panel.  Came to the conclusion the the best M20F with "all the 201 mods" was a M20J.  At the time (2017), you got a 10 year or newer airplane for the same price - and it had "all the 201 mods" built in.   Ended up buying a 1984 M20J.  It has the single piece belly and the blended wing tips.  Previous own had installed after market speed brakes.  You also get a wider airspeed envelope for the landing gear with the electric gear (133 kts gear extension and down) which is quite helpful.

Bruce

[1980Mooney]

4 hours ago, rturbett said:

Thank you!

Been discussed many times....

Model chronology:

https://www.mooneyevents.com/chrono.htm

https://mooneyspace.com/applications/core/interface/file/attachment.php?id=111107&key=52c2c56371dd70275fb2b25f9e2a3cf6

 

You have to be careful with some of the statements above.  The last J models (S/N24-3201, 3218+) came from Kerrville with 2900 lb GW, and the others -1686 thru -3200, -3202 thru -3217 can be modified per "paper" STC to get the 2900 lb. GW.  Pre ‘88 are stuck at 2740 lbs. Wingtips were added to J's in ‘81 and one piece composite belly in ‘84.  But some earlier models were subsequently modified to add these features.  Also only the last J models came with fiberglass interiors.  The vast majority came with the "Royalite" ABS that is flimsy and gets brittle with age, sun and heat.  

With highly modified F's, be aware that it may be harder to find parts if it ever needs repair to the mods (i.e. rare cowling mods, etc).  @M20F-1968 has a highly modified F and may answer specific questions that you might have.

So you have to look carefully at each particular plane that is for sale. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[1980Mooney]

13 hours ago, rturbett said:

What other differences are there between an F that is full of the speed mods- ie one pc belly, seals, windshield, and a factory production J?

Thanks,

Rob

Also the later F's had the more modern and standard instrument panel layout.  However many earlier panels have been modified

https://www.knr-inc.com/products-list.html?view=article&id=55:1ip-mooney-pre1969&catid=20:manufacturing

[EricJ]

10 hours ago, ArtVandelay said:

77 was a transition year.
78 got rid of the throttle quadrant, going to push pull controls, increased Vle.
ALL: Improved engine intake, making the ram air superfluous (was removed in later years). Annunciator.

This is why 77 is the best year for the J.         It has all of the benefits of J models, and retains the throttle quadrant and hand crank for the emergency gear deployment.   There are a number of other subtle benefits as well, like the glareshield, gear actuator without a no-back spring, etc.

 

4 hours ago, Shadrach said:

 A lot of that stuff adds weight and bragging rights but little else. The cowl and windshield are worthwhile for styling alone. The one piece belly ads weight (~15lbs) for the convenience of easier removal.

Yes, many of the "improvements" are compromises, but that's often the case.   The cowl, intake, baffles, etc., make big differences for both performance and ease of maintenance.

Also, while the engine is still an IO-360 in both the F and J, the J model engine has a crankshaft with dynamic counterweights and the dual magneto.   Some, like me, think the dual mag is a good thing, but many feel otherwise.   It is, however, a difference between the typical F and J models.   Some Js have been converted to separate mags.   Both the F and J can be converted to an IO-390 as well.

[Vance Harral]

1 hour ago, EricJ said:

and retains the throttle quadrant

Yes, those of us with the superior quadrant-design engine controls continue to pity the poor majority of sad Mooney owners who must make do with push/pull controls and their infernal vernier knobs. 

[Shadrach]

6 hours ago, EricJ said:

This is why 77 is the best year for the J.         It has all of the benefits of J models, and retains the throttle quadrant and hand crank for the emergency gear deployment.   There are a number of other subtle benefits as well, like the glareshield, gear actuator without a no-back spring, etc.

 

Yes, many of the "improvements" are compromises, but that's often the case.   The cowl, intake, baffles, etc., make big differences for both performance and ease of maintenance.

Also, while the engine is still an IO-360 in both the F and J, the J model engine has a crankshaft with dynamic counterweights and the dual magneto.   Some, like me, think the dual mag is a good thing, but many feel otherwise.   It is, however, a difference between the typical F and J models.   Some Js have been converted to separate mags.   Both the F and J can be converted to an IO-390 as well.

"Big difference" is relative.  We engage in a hobby in which owners of various makes speak of a 6% speed delta like it's tremendous performance upgrade.    I did not mean to suggest there are not benefits to the later models, I am just of the opinion that many of them are more sizzle than steak.  For years I have wanted to do an in flight speed comparison between my very stock F and a J model but it's never materialized for a number of reasons. One of which is that I have been too lazy to reclock my governor linkage arm to get max RPM; there's no point until that's remedied.  I think @jetdriven's very carefully rigged J is at the top of the 200hp Mooney speed podium and is about 13mph faster than my F given his posted race numbers. That kind of performance is important in a race.  In terms real world block times at cruise settings, it's probably 10 mins at most on a 500nm XC.

The cowl is certainly has more drag. However, I think it looks much worse than it actually is (The guppy is no looker by any measure). I am surprised that Mooney never published the differences in Cd for marketing purposes. In terms of cooling, I have never operated an IO360 that runs as cooler than mine. Granted, I have spent some time tweaking the baffle and seals. As it stands it's a challenge to keep all cylinders above 300° at cruise settings.  Some of the Js timed to 20° no doubt run even cooler.

If you hadn't noticed, I really do think the early manual gear Fs are one of the best GA combinations of speed, load hauling and reliability.  I used to talk to my partner about mods and upgrades. After 20 years of flying it, I can say that it gives so much more than it takes in terms of performance for ownership cost that it's hard to justify messing with it. To justify an upgrade I'd have to move to very specific model years of TN'd Bonanza's, a twin or kerosene burner to get any real jump in performance for my mission which is family of four and 4 hr max legs. There just aren't that many GA planes under 100K that will go 500NM in under 3.5hours with 800lbs in the cabin for so little fuel... There many that will do each of those things. Doing them all together makes it a great family truckster.

Love to learn the virtues of the duel mag. Can you link a post where you've sung it's praises?

[802flyer]

I have a F with basically all the good mods besides the one piece belly. I cruise around 145-150kts TAS on 8-9gph LOP usually around 8000ft. Not quite as fast as a J, but not by enough that I lose any sleep over it.

The one thing Js have that I’m jealous of is the higher gear extension speed. I’ve gotten used to planning my descents such that I can slow to 120mph and get the gear out at an appropriate spot on the approach or in the pattern. But if I don’t get to plan my own descent (eg slam dunk by ATC), I get jealous of being able to swing the gear at (nearly) cruise IAS rather than just above the white arc.


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[EricJ]

2 minutes ago, Shadrach said:

Love to learn the virtues of the duel mag. Can you link a post where you've sung it's praises?

Mainly that you can get spark to both plugs during start, which benefits starting.  It also frees up some space to work around the accessory area, which I think was one of the main reasons for their development and is useful in a Mooney.  They seem to wind up having overall lower cost of ownership/operation when it comes to maintenance, overhauls, etc.    If installed properly there's insignificant downside compared to separate mags.   The only shared components are the case and the magnet.   Failures of the common components are essentially unheard of, and past that it's essentially the same as having separate mags.

The Rolls-Royce Griffon engine also had a dual magneto, so they're battle-proven as well! 

 

[FlyingDude]

19 minutes ago, 802flyer said:

145-150kts on 8-9gph LOP usually around 8000ft.

TAS or IAS?  thank you.

[802flyer]

TAS or IAS?  thank you.

TAS. Will update the post


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[MikeOH]

Meh, J’s slightly better performance vs F’s very noticeably lower cost…. Juice just isn’t worth the squeeze!

 I see 145 knots true at 8000 burning 9 gph LOP.

Love my F 

(still wish I had manual gear)

[A64Pilot]

If you want a 200 HP NA Mooney and are the type that thinks a couple of kts in either purchase price or mods is worth tens of thousands of dollars then in my opinion you want a J.

If you either don’t want to spend the cash, or can’t afford the buy in price, then you want an F.

I wanted a J because it’s what I flew back in I think 92 to get my Commercial / Instrument, a couple of brand new AT’s and have wanted a Mooney ever since, but I needed tailwheel time when I Retired from the Army and bought a Maule instead, then had use of a C-210 so I didn’t need a Mooney. Interesting to me was the Maule and C-210 burned exactly the same amount of fuel over a distance, but the 210 was 25 kts faster and had two extra seats and lots more useful load. But then strange as this sounds but my J gets much better fuel mileage than a Piper Cub.

I think best bang for the buck may be an F, but they are getting old, but then so are the J’s. I think by the time an airplane hits 30 or so age is irrelevant, then it’s condition and maybe airframe hours.

If you have money and want speed, then I don’t think either an F or a J will do, you need a “Big Block” Mooney, because there isn’t any replacement for displacement  

[Shadrach]

24 minutes ago, EricJ said:

Mainly that you can get spark to both plugs during start, which benefits starting.  It also frees up some space to work around the accessory area, which I think was one of the main reasons for their development and is useful in a Mooney.  They seem to wind up having overall lower cost of ownership/operation when it comes to maintenance, overhauls, etc.    If installed properly there's insignificant downside compared to separate mags.   The only shared components are the case and the magnet.   Failures of the common components are essentially unheard of, and past that it's essentially the same as having separate mags.

The Rolls-Royce Griffon engine also had a dual magneto, so they're battle-proven as well! 

 

Those are good points. The accessory area is tight and requires a thoughtful, patient approach. It has taken a few mag overhauls but I now have the modified tools and know how to pull the mags without removing anything else.  Back in the early aughts my local shop invoiced 7 hours to exchange and time the mags, which included removing the Vac pump, unbolting the top engine mount bolts and rotating the powerplant forward.  Mechanic explained it all to me.  I don't blame him. However, it's not necessary.  I would love to have a retard breaker on both mags.  However, operationally the single mag SOS puts out a pretty robust spark.  I have had few starting problems, when I have it's been a maintenance issue. 

[dzeleski]

I went for an early J because it seemed to be a good sweet spot $$ vs UL vs speed. I have a very early J (0095 sn) with a current UL of 1006lbs. Granted I no longer have a vacuum system. It seemed a lot of the later J models had much worse UL. My J also has the blended wing tips, gap seals, dorsal seal, etc. Another major reason I went with the J is age, 46 years is old enough IMO.

I know a lot of people hate the quadrant but I love it. Ill miss it if I ever swap to something else.