J or K?

[chrisk]

Both the J and K are nice planes.  I think either will work for you.  I would not get stuck on either one.   Do be aware that the K will use about 20% more fuel.  K's also tend to come with additional equipment like O2 and hot prop, which is nice when you fly high, but that doesn't sound like your mission.  I'd probably put more weight on air frame and avionics.   Which one has been maintained better?  Which one has flown regularly? 

[Danb]

Easy decision I went from a Cherokee to two am models then than M model.

Your mission is spot on for a J,E,F or C, find the best for your buck and join the group of travelers 

[jwilcoxon78]

I'd go with the J.  That 750 is great.  I joke that it runs a close second to which one I'd rather have operable, it or the engine.  

[Jerry 5TJ]

10 minutes ago, Danb said:

Your mission is spot on for a J,E,F or C, find the best for your buck and join the group of travelers 

✔️
 

Buy the plane in the best condition, with the best maintenance history and best modern avionics you can find.    

[c131fr]

Thanks everyone.  I appreciate the input. 

[Gagarin]

On the M20J you will never have a broken turbo

On the M20J you will never have an empty oxygen tank

On the M20J you do not have two extra cylinders to break 

On the M20J no cylinder cracks like these http://www.tcmlink.com/pdf2/MSB09-1B.pdf

On the M20J you will arrive earlier because you will not be wasting time on the above.

 

 

Edited December 31, 2019 by Gagarin

[Bob - S50]

For the OP mission, I think the J fits the bill better for the following reasons:

1.  Since 75% is 75% not matter whether it's turbo or normally aspirated, both the J and K will go the same speed below about 7000' at the same percentage of power.  However, since the compression ratio on the J is higher than on the K, the fuel flow will be lower on the J.  Thus, for flights below about 7000', the J will save him money and cost zero time.

2.  For flights less than 300 NM (further than either of the typical flights the OP talks about), the difference in total fuel burn will be less than a gallon regardless of what altitude he cruises at.  That is, it won't matter if he flies at 2500' or 8500', the fuel burn will be about the same assuming no wind.

3.  The same can be said for time.  The difference in total time will be less than 5 minutes.

4.  Considering both #2 & #3, the best thing to do on those short flights is to pick the lowest altitude with a smooth ride and favorable winds.

5.  Someone earlier referenced being able to get above the popcorn Q in the summer by climbing up to 12,000'.  On that short flight the OP mentions, by the time he gets up to altitude, he'll only spend about 10 minutes in cruise before he has to start down.  On the longer flight it might be worth it.  On the other hand, it's not that hard to make small heading deviations to go around that stuff.

I think there are only a few GOOD reasons to buy a K vs a J:

1.  Takeoff performance at high density altitudes.

2.  Quicker climb to altitude for LONG flights.

3.  Higher TAS on LONG flights IF you AND YOUR PASSENGERS are willing to suck on oxygen.

4.  Able to take advantage of higher tailwinds IF you AND YOUR PASSENGERS are willing to suck on oxygen.

5.  Able to take a more direct routing over mountains by climbing to a higher altitude IF you AND YOUR PASSENGERS are willing to suck on oxygen.

[anthonydesmet]

Oh boy....these discussions are always fun to watch.....

your mission definitely supports a J. I use my K for both J and K type flying.  My original missions are for 600+ miles and enjoy flying in the high teens and don’t mind oxygen. If you think you might in the future start becoming a cross country Mooniac and experience some adventures outside 400+ miles then you would be happier with the K.

[ArtVandelay]

J is the Goldilocks pick of all the Mooney models.


Tom

[Bob - S50]

1 hour ago, anthonydesmet said:

Oh boy....these discussions are always fun to watch.....

your mission definitely supports a J. I use my K for both J and K type flying.  My original missions are for 600+ miles and enjoy flying in the high teens and don’t mind oxygen. If you think you might in the future start becoming a cross country Mooniac and experience some adventures outside 400+ miles then you would be happier with the K.

One other thing to consider.  How long are you and your passengers willing to sit in the plane without a break?

For my wife, that's about 3 hours although we have gone longer under certain circumstances.  Three hours of flying is going to be 500 NM or less unless you have a strong tailwind.  So even the 'long' trips won't be that long.

The furthest my wife and I have flown in one day is S50 (7 miles from SEA) to GFK (Grand Forks, ND).  That's about 1000 - 1100 NM with one fuel stop at Roundup, MT just north of Billings.  My favorite altitudes for long trips range from 7500' to 10,500' depending on terrain and winds.  At those altitudes, I can plan on 155 - 158 KTAS, LOP and <= 9.3 gph.

[PJClark]

C'mon. @c131fr knows what he REALLY wants. He wants encouragement.  He's  really hankering for a rumbling great huge enormous turbocharged fire breathing ROCKET!

Which, @c131fr, is a 231 or a 252 that has had the TSIO-360 replaced by a TSIO-520NB of 305 hp.  And gross weight increase to 3200#.

Gets the blood goin' let me tempt you: 6500 MSL, 65% power, 17.5 gph, 178 KTAS.  OR

LOP, same settings, 13.2 gph, 169 KTAS. Just did it 78 miles each way last week to get my kids for Christmas.

And the best part-same fuel flow, the higher you go the faster you go.  15,000 MSL, 195-200 KTAS is easy....loafing at 65% power.

I leadeth you into temptation:

https://www.controller.com/listings/aircraft/for-sale/165598829/1979-mooney-m20k-305-rocket

:-)

PJ

 

 

[gsxrpilot]

One of the nice things about a turbo is the ability to maintain power into thinner air.

Today coming back from Salina, KS we had a hell of a head wind. And it got significantly worse with altitude. My brother suggested 6500 as a cruising altitude. At that altitude we were doing 140 TAS and 127 GS. After sitting there for a few minutes I suggested we go higher even though the winds would only get stronger.

At 12,500 ft we were getting 170 TAS and 145 GS. Of course the fuel burn was the same. Turbos burn the gas you'll feed them regardless of altitude. But they will always go faster at higher altitudes regardless of the increased headwind.

I've only put 1000 hours on my 252 but I haven't had any of the issues @Gagarin mentions. And this is the 1000 hours closest to TBO, not new hours. I still have all original cylinders and the original turbo. But then I have an engine monitor and know how to use it. I also fly LOP most of the time. The O2 bottle is never empty, but if it was, it would be exactly where a J is all the time. 

Having said all that... I agree with @Bob - S50, the J is the right answer for the OP's mission. 

 

[aviatoreb]

2 minutes ago, gsxrpilot said:

One of the nice things about a turbo is the ability to maintain power into thinner air.

Today coming back from Salina, KS we had a hell of a head wind. And it got significantly worse with altitude. My brother suggested 6500 as a cruising altitude. At that altitude we were doing 140 TAS and 127 GS. After sitting there for a few minutes I suggested we go higher even though the winds would only get stronger.

At 12,500 ft we were getting 170 TAS and 145 GS. Of course the fuel burn was the same. Turbos burn the gas you'll feed them regardless of altitude. But they will always go faster at higher altitudes regardless of the increased headwind.

 

Right on.  And then said in reverse the ground speeds can be amazing when up high and with a tail wind.  18k with high TAS and high tail wind makes for fun GS.

[gsxrpilot]

2 minutes ago, aviatoreb said:

Right on.  And then said in reverse the ground speeds can be amazing when up high and with a tail wind.  18k with high TAS and high tail wind makes for fun GS.

I'm always disappointed when I can't get 200+ knots GS going east.

[aviatoreb]

23 minutes ago, gsxrpilot said:

I'm always disappointed when I can't get 200+ knots GS going east.

Wait - I don't understand.  Why would you ever need to go slower than 200GS going east bound?  East bound 300 is the magic number which I have hit a few times, the highest being 327GS.

[gsxrpilot]

7 hours ago, aviatoreb said:

Wait - I don't understand.  Why would you ever need to go slower than 200GS going east bound?  East bound 300 is the magic number which I have hit a few times, the highest being 327GS.

LOL... well at only 9.5 gph, I might not quite get it sometimes. 

[aviatoreb]

8 hours ago, gsxrpilot said:

LOL... well at only 9.5 gph, I might not quite get it sometimes. 

...well you definitely got me there on fuel.

But honestly - on those 300kts days, you would do almost the same speed as me since on 100kts+ of tail wind we sometimes find up high in the winter will even make a balloon go fast.

[gsxrpilot]

2 hours ago, aviatoreb said:

...well you definitely got me there on fuel.

But honestly - on those 300kts days, you would do almost the same speed as me since on 100kts+ of tail wind we sometimes find up high in the winter will even make a balloon go fast.

It does happen though... this is on the way to Oshkosh last summer. The best thing about a turbo is the ability to go take advantage of the wind when it's up there.

 

[tmo]

21 hours ago, PJClark said:

https://www.controller.com/listings/aircraft/for-sale/165598829/1979-mooney-m20k-305-rocket

And he can convert the PPI into a full annual ;-)

[larrynimmo]

For what it’s worth, I bought my J two and a half years ago...and I debated buying the K and at this point I’m glad I stayed with the J.   When I first bought the J it was all about speed...I ran rich of peak 25/25 12 gallons per hour at just over 150 knots.

as time has gone by I came to realize most of my trips were pretty short...like 15 to 20 minutes in the air...and I felt that I needed to spend more time flying and now I run 22rpm 25man lop 7gph and yield about 123k...which will give me reliable 20 statue miles per gallon.

this way I am reducing my tach time for hours flown and hopefully reducing wear and tear.

ive been running at these settings for the past year for most flights...it doesn’t stay consistent with higher altitudes

[INA201]

I’m with having the GTN750 over the turbo.  Also you are going from a 172 to a thoroughbred so congratulations!  You will be pleased with either.  Get a great prebuy! Also, Please get good transition and safety training!

[M20F]

On 12/30/2019 at 4:34 PM, gsxrpilot said:

I'll agree and disagree with @jrwilson. I have a 252 which is like a 231 only better  but I still like the M20J for any flight below 10K feet. 

I LOVE my 252 and wouldn't trade it for anything short of an MU2. But if I were in your shoes... in Illinois, I'd have an M20J. 

 

Words of truth and wisdom. 

[M20F]

On 12/31/2019 at 4:26 PM, gsxrpilot said:

My brother suggested 6500 as a cruising altitude. At that altitude we were doing 140 TAS and 127 GS. After sitting there for a few minutes I suggested we go higher even though the winds would only get stronger.

At 12,500 ft we were getting 170 TAS

I see @ 1% per 1000’ in TAS give or take.  6500 to 12500 you jump 20% with same power settings?

[CaptRJM]

I have been flying my K for almost 1000 hours and simply love it. Since I live in N.C. and the vast majority of my missions are in the SE folks will tell you a K is a waste of money. After a lot of XCs I will disagree. 
 

In the mid teens I true out between 170-175 running LOP at 65% power (9.9 GPH). However, my typical mission is 4-600miles each way so I can take advantage of winds aloft. Another other big benefit is to get out of most thermal activity and get a smooth ride. More than once we’ve been comfortable at 16K where at 12K you’d be getting bounced around in hard IMC. 
 

But with a mission of less than 200 miles you can’t take advantage of the high altitude performance of the K to justify the additional operating expenses. The J model is also slightly faster below 8K. 
 

If I were in your situation I wouldn’t consider any Turbocharged aircraft. 

[rbridges]

On 12/30/2019 at 3:04 PM, c131fr said:

My manly manhood says get the K because real men turbocharge six-bangers

But CB mooney owners get normally aspirated 4 bangers b/c they're kinder to the overhaul wallet.