C to K

[jrwilson]

I just recently bought an 84 K (intercooler/LB/gamis/Built in 02) after 12 years in a 63 C.  Love it!  No complaints.  the extra room is really noticeable and the wife loves the extra backseat room with reclining seats, makes it easier for her to nap on longer flights. 

I get 170 + kts true above 12,500 and 174 at 15k.  Fuel burn with intercooler at 75% is just under 13gph.  I don't do LOP.  CHT and TIT temps are really cool. 

On equal length flights between the K and C, total fuel burn is identical.  K gets me there faster but I burn a bit more.  So basically, faster, better range, much more comfortable and same gas.  Annuals are predicted to be more, but lots less screws to remove so that's a plus (1 piece factory belly/Cowling has the quarter turn fasteners).

I really liked my C, but I don't miss it since I have the K...

Edited October 28, 2015 by jrwilson

[flyer7324]

Yes 14,000 is doable in C for those occasions when u would like to get out of the wx. The K does offer more options. Take for instance tomorrow. I'll b flying my C from KAPF-KHRJ-KHVN. with nice tailwinds it'll be about 6.5 hours with fuel stop at 9500. With a stock K at 15500 at economy cruise it'll be s little over 5 hours nonstop with about the same total fuel burn. For jollies reverse the route and although it's not nonstop the K at say 10500 will reach the destination in significantly less time on much less fuel.

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[Bennett]

I had my 261 conversion for over 16 years and regularly flew her in the flight levels - mostly FL210 and FL230 eastbound, with higher flights when the winds were right. Never had a problem with maintaining decent engine temps. I always ran her WOT and leaned to about 150 degrees ROP. Yes, this is hostile territory, but I always had a backup O2 tank already hooked up with good masks and the main O2 built in tank had flow meters in sight. With long range tanks I crossed the country many times at high speeds with powerful tailwinds. Not particularly comfortable, even with conformal foam seats, but I was always anxious to get to Florida as quickly as possible. Today I have a J model, and at the typical altitudes I now fly: 7000' to 9000' my J is just as fast, burns a bit less fuel (and a whole lot less LOP) and with far lower maintenance costs. Both are great airplanes, but consider the reason you want a Mooney.

[flyer7324]

Thx for the post Bennett! How fast does your true out at?

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[peevee]

Flying high us nice, but to really be useful, I would need FIKI, now I could fly high and not worry about icing up on the way down.

 

agreed, with FIKI this would be the perfect plane... and maybe a little more gas with the FIKI and no loss of gross!

[M20F]

I I looked at 252/231 in my search and quickly shifted to a normalized E/F (preferably an F which is what I ended up with).  For the few times a year the winds favor going high I can get 160-170kts in the low FL's and 26/26 till about FL180.  I agree it works great for avoiding CB's in the summer as well.  

For me though I just don't take enough 4+hr trips a year to where a full time turbo was worth it (or the winds don't support the altitude like one I just took that was 4+hours).  Most of my trips are local or 2-3hrs where 8000-9000ft works great.  In the end I get the functionality of a turbo to get around weather, faster than a J in ideal circumstances, low operating cost, and for the short trips I am going to be within ten minutes of anything from a A to an S.  All for about half what a nice K will cost you.

If you are doing a lot of long distance trips than 252/231 with long range tanks is a dream machine.  Buying one though for hitting +12000 ft a couple of times a year is a really expensive proposition both in purchase price and on going maintainence.  This is merely the logical side, for the most part all plane purchases are illogical money pits so enjoy whatever you choose.  

[flyer7324]

M20F I agree! I fly 130 hours year. At least 100 if that is KHVN to KAPF and back. About 5-6 trips/year.

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[M20F]

M20F I agree! I fly 130 hours year. At least 100 if that is KHVN to KAPF and back. About 5-6 trips/year.

 

 

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Definitely a turbo/long range tank mission.  The fastest speed mod out there is long range tanks, definitely want them with your requirement.  Good luck in your search!

[chrisk]

Flying high us nice, but to really be useful, I would need FIKI, now I could fly high and not worry about icing up on the way down.

 

One of the nice things is most 231s are equipped with a hot prop. --If you ever got ice on a prop, then you understand!  If not, power back to idle so your engine doesn't shake it self to pieces.  --It's certainly not FIKI, but the option of up is there if you find some unexpected ice.

[peevee]

One of the nice things is most 231s are equipped with a hot prop. --If you ever got ice on a prop, then you understand!  If not, power back to idle so your engine doesn't shake it self to pieces.  --It's certainly not FIKI, but the option of up is there if you find some unexpected ice.

Ours doesn't 

[carusoam]

ChrisK's flight data indicates he is flying faster and further than an IndyCar in May.  

Plus, room for four, no pit crew required, and much better gas mileage.

Go Mooney!

Best regards,

-a-

Edited October 29, 2015 by carusoam

[SkyBound]

I transitioned from a 1970 M20C to a 1979 M20K 231 with the Merlyn/GAMI/Intercooler/Speedbrakes.  I fly LOP 10-11 GPH and get 165 TAS in the mid teens and 170-180 TAS in the flight levels.  I have gone up as high as 23,000 ft. I am based on the East Coast and frequently fly in the teens for anything over an hour.  I love the airplane and the transition from the C was easy.  I'd be happy to talk more on the phone about my experiences if you'd like to PM me.

[M20F]

Great article!

I couldn't find his name, but it reads like Bob Kromer wrote it? Boy did I enjoy meeting him (and his beautiful wife) and hearing his class at the Mooney Summit! 

I'd like to read his article on the 252 ... wonder where you can find it? 

http://www.mooneypilots.com/mapalog/M20K252_evaluation_report.htm

[Flying Crab]

I'm a fairly new (2 years) owner of stock 231K LB. As of now everything in it except electric tach and G530W is as it it came out of Kerville. Commute between Houston and Pagosa Springs Colorado in the summer. Coming out of Colorado normally fly at 15,000-17,000. . I personally think that intercooler and waste gate money could be better spent on avionics upgrade. This engine  can be monitored and flown in a manner that I believe will return exceptional performance and longevity compared to higher cost aircraft. I hear about running LOP which I think is saving pennies to spend real money later on in cylinder replacement or early engine overhaul. One of the things that fuel does in a cylinder is provide lubrication. This airplane is not a 172 where there is basically three positions of the throttle and mixture. This airplane has to be monitored and  manipulated depending on the phase of flight you're  in. There are airplanes out there that can fly faster and require less input from the pilot but as the old saying goes "speed costs money, how fast do you want to go?". I have 1400 hrs. on my engine with the original cylinders. This is my method of operation (so far). Take off 40in. 2700. 1000ft. transition to climb at 120 knots 40in.2600. Adjust throttle to maintain 40 in. Throughout the climb (attainable) up to around 17,000 DA. Manipulate cowl flaps as needed to keep oil and cht's in the green. Level flight regardless of altitude 31 in. 2500rpm 1450-1475 TiT.  This should get about 11.5 - 12.5 gph. Below 10,000 that should be around 160 TAS. 10,000-15,000 about 165 and above 15,000 around 170.  This airplane will definitely go faster but speed will cost you money.

[231LV]

I was a C owner for about 4 years and then traded up to a K which I have owned now for about 13 years. The difference between a C and K is pretty significant. Before making the switch, carefully examine your typical mission. If you don't ever plan on flying mountains, a J is a great plane. If you plan on mountain or other higher altitude flying, a turbo is the way to go. That said, once you have decided to go with a turbo, then it becomes a matter of budget. There are several great turbo variations. The 231 is your least costly turbo. Most 231's are already upgraded to the LB engine (I still have a GB in mine). You would also want an intercooler, as well. If your budget allows, a 252 is the better plane between the two, in my opinion. There are a small number of specific serialized 252's that can be upgraded to an SB engine but requires heavier landing gear, etc and more money. The price difference between a stock K and the 252 is about $50k...give or take. 

All that said, I love my K and can't imagine flying a non-turbo. I fly out of a higher elevation airport so my turbo is used. The intercooler is a must, in my opinion and an automatic wastegate would be a nice improvement over the stock fixed, if you can find a plane with one. The difference between the C and K is night and day...a K will overtake a C in a climb, it has more room in the back seat and has a "cooler" long nose look (in my opinion). It also typically comes with much better avionics and an autopilot. The engine is heavier so turns will pull the nose down until you get used to it. K's burn about 2 gph (LOP) and closer to 5 gph (ROP) more than a C but are at least 15 to 20kts faster down low and up high, 30 plus kts... My true is about 175 at 10.5 gph at 17k ft running LOP. Of course, I have an old, tired GB engine. 

Edited May 17, 2017 by 231LV
correction

[peevee]

Noob bumped a nearly 2 year old thread.

[KLRDMD]

3 hours ago, Flying Crab said:

I hear about running LOP which I think is saving pennies to spend real money later on in cylinder replacement or early engine overhaul. One of the things that fuel does in a cylinder is provide lubrication.

. . . as the old saying goes "speed costs money, how fast do you want to go?"

You may want to do a bit more research on LOP operations as you're repeating old wive's tales with no basis in fact and with tremendous data to refute your position.

The old saying is actually "speed costs money, how fast can you afford to go ?"

[Flying Crab]

They must have been teaching old wives tales in the flight engineer school and the A/P school I went to

[gsengle]

They must have been teaching old wives tales in the flight engineer school and the A/P school I went to

Yes probably. Unless you're from the WWII generation back when they taught LOP... but if you worked back then you'd be in your 90s. Somehow it got forgotten in the middle.


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[Flying Crab]

Yea it was back when scientists were touting global cooling.

[gsengle]

Yeah that proves that everything we knew in 1945 was wrong...


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[LANCECASPER]

8 hours ago, 231LV said:

There are a small number of specific serialized 252's that can be upgraded to an MB engine but requires heavier landing gear, etc and more money.

All 252's came with the MB engine. You might be thinking of the TSIO-360-SB engine.

[KLRDMD]

22 minutes ago, Flying Crab said:

They must have been teaching old wives tales in the flight engineer school and the A/P school I went to

Yes, I imagine they were.

[gsxrpilot]

1 hour ago, Flying Crab said:

They must have been teaching old wives tales in the flight engineer school and the A/P school I went to

And evidently you're still relying on that ancient and thoroughly debunked information.  Welcome to the 21st century 

[Flying Crab]

Don't believe everything you read on the internet boys, you just might end up dating a French model. Fact is, the proof is in the pudding as they said in the old days. If you have an engine that's made it to TBO untouched I'll be listening. Until then I'll be the cat that's running ROP.