Shadrach

One reason would be getting a great deal on a low time, IO360. Another would be the wider range of mixture options and increased efficiency. Yet another would be that the angle valves run much cooler than the parallel valve and rarely require step climbs or power reductions on the way to cruise altitude. As a bonus you get the added climb performance of the 11% horsepower jump and a few knots in cruise. Why did you all pursue the STC if you did not think it worthwhile?

The only way to verify all leaks is to observe the tank under vacuum. Even then it's a good idea to repeat the process and check again. I usually mark any observed leaks with a sharpie and then spray again and observe. I really don't dread tank repairs like others do. I would open up a side business if I were credentialed. It's straight forward, methodical work that yields gratifying results.

I take all of that into consideration. There is a lot more to manage. If I was looking for a "Mountain" Mooney that would handle shorter strips, I would be looking for the lightest TN'd M20E or M20F I could find. >1700lb empty weight Excellent engine cooling High Comp Engine

On a side note, whoever did the sump relocation AD on the OP's bird did a nice job.

The honest assessment is indeed appreciated. I have never flown a K model. Last spring, I was admiring one that was just ahead of me in the queue to take off from my home drome. I took off about minute after him in the same direction. I thought I was imagining it as he got larger in the windshield, then tower called notifying me that they had gotten a collision alert and to ask me if I still had the traffic in sight. I was above him and overtaking on the right when he turned south at the VOR just 5.5nm from the the departure threshold. I was initially surprised that my stock, 56 year old Mooney would keep up with, much less overtake but after checking his flight track and doing a little research on the flight profile of other Ks I understood. It's a heavier aircraft with ostensibly the same HP but a more temperamental powerplant necessitating conservative operation. It's a specialized aircraft. It climbs and takes off consistently but it is meant for high altitude, long distance XCs where no other 4 plc single will go as far, as fast on so little gas. What it is not is a low altitude hot rod nor a short field take off champ.

That can likely be repaired. The cost to remove and reinstall the inspection panels is nominal. I have been into my tanks three times in the last 20 years. They were supposedly stripped and resealed in 1999. As it turned out, they were only mostly stripped and resealed. There were still areas of original sealant. Over the years I have removed the remainder and repaired as necessary. At this point, I look at the tanks as an area that will need minor mx every five to seven years. All of my issues have been annoyances rather than airworthiness issues (per the maintenance manual). Internal source of failure is rarely obvious to the naked eye. The best way to determine location is to spray the inside of the tank with soapy water, tape plexiglass over the access panels and observe the inside of the tank under vacuum. The best way to fully observe the tank interior under vacuum is to place mirrors and lights inside during the process.

The scenario for me was that mine passed inspection every year. At some point I jacked up the plane during a period of sustained temperatures >30°. The shocks did not expand and the gear had a noticeable amount of slop in its travel. I checked again after an hour on the jacks and everything was back to normal. I ordered new shock discs shortly there after.

In my experience, what passes in the warmth of June might fail in the chill of February.

call Herber. Ask for Dwayne. Pricing was much better than Spruce when I did mine in 2021. https://www.herberaircraft.com

Obviously not done by them…Urologists know their way around tubes…

That’s poorly routed. It looks like the previous owner tried to save money on scat tube by using the most direct rather than the least invasive route. That 3” hose should be longer, lower and against the firewall. The 1.25” hose should route above the 3” hose and also be against the firewall.

Interesting. It seems to me the low powered tail dragger set is the oldest group around my drome. We I know of 2 guys in there late 70s. One flys a Daphne that he built himself and the other flies a Decathlon and also a pitts S2B (recently sold).

Using my F as an example. At 8,000’ the turbo is pulling an airframe that is 20-25% heavier with 18-22% more horsepower. That spread gets better as the DA goes up. That being said I think the takeoff advantages at DAs below 10K are probably overstated.

This has always been my view of where they shine. I looked at some real world W&B numbers on line. Most are 300 to 400lbs heavier than my F model. According to my POH the engine will make 83% hp at 7500’ and 77% at 10,000’ on a standard day. It would interesting to see the real world delta in runway performance at altitude.

I am not an expert on the any of the euro diesels. I do own a 3.0L BMW diesel but I am still learning about it. The emissions side has been the only thing to require maintenance in 170k of driving. I agree that they have become overly complex. I suspect that mixture is very much controllable with piezo electric injectors. They can fire up to 8 times in a single combustion cycle. I suspect the engine may have a throttle valve because of the significant engine breaking when down shifting. On the whole it feels like a gas car with an inverted powerband. It will rev to 5500 but max torque (413ftlbs) is 1500-2500. It would make a decent aero engine although I can’t find a weight without all of the emissions stuff. It’s likely quite a bit porkier than an IO360.

That may be true. Even so, the K model is not really the take off champ that people would have you believe. Perhaps I am misreading the convoluted graph.

Congratulations on your new to you F model. I operate my F LOP frequently. Operationally, it's quite simple but one should really gain a rudimentary understanding of what is actually taking place under the cowl to optimize both efficiency and safety. It's for good reason that the articles linked below have been a staple for those looking for a deeper understanding of engine operations. They are the best "self study" starting point that I know of. John Deakin passed in 2021 but he left a legacy of excellent aviation related content that is still relevant today. I can offer more nuanced advice regarding how I operate my 67F but it will not be of much use to you until you have a foundational understanding. https://www.avweb.com/features/pelicans-perch-63where-should-i-run-my-engine-part-1/ https://www.avweb.com/features/pelicans-perch-64where-should-i-run-my-enginepart-2-the-climb/ https://www.avweb.com/features/pelicans-perch-65where-should-i-run-my-enginepart-3-cruise/ https://www.avweb.com/features/pelicans-perch-66where-should-i-run-my-enginepart-4-descent/

OP asks a question about take off distances and not a single post with actual numbers. POH takeoff data for 77 J model and 85 K model. My gosh the mid 80s Mooney performance graphs were horrendous. I guess they thought that America would soon go metric and they would be ahead of the game. 1977 M20J 1985 M20K

This was the a big part of the issue with VW AG’s “Diesel gate”. They avoided installing urea injection by running the cars rich during testing. However, during normal ops the production cars ran lean which delivered their staggering fuel economy (VW TDIs would deliver in excess of 60mpg on the Highway). They could pass NOx and they could deliver the promised performance…but they could not do both at the same time. All road going diesels run lean of stoic, but they use urea injected into the exhaust for NOx reduction. As for LOP climbs. 4gph is definitely realistic…initially. The difference in WOTLOP and full rich fuel burn is more dramatic than that at low altitude. Full Rich at SL on a standard day for an IO360 is roughly 18.5gph. I have experimented with high power LOP at DAs of 0 or less and the best I can do is about ~85% and 11.x gph (rough numbers). All cylinders are >30LOP and CHTs >340. That’s a a roughly 40% reduction in burn from full rich for a 15% reduction in power. It makes good sense for low altitude cruise but does not amount to much gain in climb efficiency, because the delta narrows as you climb and define takes significantly longer because power correlates directly to climb performance. If I had a turbo, I would experiment with it, but I suspect high powered LOP may hampered by TIT limits. Some of the TN’d Bonanza folks climb LOP but I suspect the higher compression engine yields better TIT margins.

You should probably give it a second look... The aft rudder servo is plumbed into the line that actuates the right aileron. The forward rudder servo is plumbed into the line that actuates the left aileron. The system works incredibly well given it's simplicity.

Weird. Mine definitely has two. The servos actuate the rudder control tube and are facing each other in sort of “tug o war” configuration. I don’t see how you get rudder movement in both directions without two servos.

That must be unique to certain models and configurations. As I recall, in my bird, both servos are in plain view.

On more than one occasion, I’ve had exhaust probes get flakey after being disturbed. I don’t know why exactly. I’d guess that they were marginal before removal and the process finished them off. It’s good idea to have a spare or two on hand just in case.

I’d bet that it’s not original. After ten years in service, this stuff looks positively horrendous. At 57 years, I think it would be dust. All of the servos should be on rigid (vinyl?) lines (green or red) which seems to last forever.

He’s at 1573 in cruise. I do have one cylinder that will just break 1500° at low altitude at WOTRAO. 1573° at 21.5”x2520 seems unlikely.