1980Mooney

Same plane was for sale on Barnstormers a bit over a month ago for $10K more. Apparently no takers. Something wrong with it? Maybe the market is turning.... https://barnstormers.s3.amazonaws.com/media/docs/doc_SPECIFICATION_1916789_1719724910.pdf https://www.trade-a-plane.com/search?category_level1=Single+Engine+Piston&make=MOONEY&model=M20E&listing_id=2433570&s-type=aircraft

This is probably the most overlooked factor when anyone tries to compare an air cooled aircraft engine to a liquid cooled solid block automobile street engine. Rarely would your old Ford 302 be running WOT -it might be measured in mere seconds - hardly even for one minute for an automobile. Maybe in a truck application, usually derated, it might run WOT for longer periods. But our aircraft engines run WOT for hours on end. Why does that matter? Manifold pressure. A car cruising at 60 mph on a level road, no wind, might have the throttle open 1/3 or about 30-35 degrees. Engine vacuum might be 16-18 inches HG which is about 12 - 14 inches HG Manifold Pressure in our aviation lingo at SL (that is only 6-7 psi). A Lycoming IO-360 at SL WOT might be 26 inches HG Manifold Pressure at 2,500 RPM dropping to 18 inches at 10,000 ft. (that is about 13 psi at SL and 9 psi at 10,000). If the pressure is double, then the air density (number of molecules is double) and since the air/fuel ratio is in a narrow range, the number of hydrocarbon molecules is double burning with double the energy. So with the same or similar Compression Ratio to the Ford 302, the Peak dynamic cylinder pressure of our aviation engines are much much higher than typical car engines - double at SL. Yes the manifold pressure drops on a NA engine as altitude rises but even at 10,000 ft cruise we still have more peak cylinder pressure than a car cruising a level freeway at SL. - probably 30-50% more. More cylinder pressure. See the Savvy graph below. A 20% increase in manifold pressure resulting in a 49% increase in measured peak cylinder pressure. The TN engines that are at 30 inches HG all the time or turbocharged with over boost hitting 40 inches. Yes they have slightly lower static Compression Ratios in order to manage peak cylinder pressure but the turbocharged engines with 1/3 greater boost will hit the highest pressure of all. In addition to higher pressure, the air cooled engine has more hot spots - a solid liquid cooled block has better and more stable heat transfer. As @Shadrach and @A64Pilot said other variables that affect this are ignition timing, valve timing, mixture. This is a good read - https://www.savvyaviation.com/controlling-the-combustion-event/

I am not sure how familiar you are with Mooney Service Centers (MSC). Don Maxwell, located 190 nm away in Longview, TX, is premier. You probably saw that he hosts the annual MooneyMax. Maxwell is also qualified and will undertake major airframe repair that others cannot handle. https://www.donmaxwell.com/ I don't know where you are located and that may seem like a long distance to your or the Seller, but if you get a Pre-Buy from Maxwell there will be little unknown to debate regarding condition of the plane.

Other direction towards the northeast part of Arkansas.

Maxwell in Longview is a heck of a lot closer…

That is after getting about $30K for your old engine. If you have no core then the cost of a new Lycoming IO-360 is $129,000 - But none are in stock so you will likely pay more when/if you can find one. That is why the DeltaHawk is looking competitive for OEM new sales in currently manufactured airframes. Hence no interest in Mooney applications. When considering it as an engine swap on a legacy aircraft, it is competing with Overhauled and Rebuilt engines at much, much lower cost. The economics don't work. And don't forget all the extra cost for new engine mount frame, new cowling, new prop, some changes to engine instrumentation/recalibration and then you need some kind of heater modification. Costs which you would not have with an overhauled Lycoming (maybe some over haul cost for prop and repaint for engine mount frame but no cost related to the cowl or instrumentation or heater). I bet those things easily add another $30,000 on top of the engine - probably more. Hence no interest in Mooney applications.

You are both correct in your assessments. I should’ve been more clear. I agree with. @EricJ that there is no leak in the tubing between the and the ASI. And I agree with you that the only other thing that could have failed is the sensing mechanism (springs, microswitch). If the diaphragm in the switch had failed, there would be a continuous leak, which would give you a low speed reading in the ASI. I have the old style sensor, which screws directly into the back of the ASI. The diaphragm in that looks like some kind of rubberized fabric. Over time and heat mine got brittle which affected its ability to flex and therefore the speed at which it tripped. My diaphragm also eventually developed a leak The newer switch looks like it’s made out of something much more durable.

WTF. That is two (2) owners ago. That owner (now 71 years old) sold it in 2019 and let his Medical expire in 2020. I am surprised that his wife, whom he acknowledged to ATC was on board, allowed him to continue flying a few years and didn’t make him immediately sell it in 2016.

I think @EricJ is right. If there was a leak in the pitot line then the pressure would be low on BOTH the landing gear switch and the ASI. In that case the continuity test on the switch would trip at a normal approx 60 KIAS shown on the connected ASI. - but because of the leak, the plane would need to travel faster than 60 KIAS to create the same pressure in the pitot system. But that is not the case.

That’s the other thing. How many months are you whiling to have your plane down?

You bought a nice-looking plane. But one would need to know more about your goals. Like everything in aviation "its complicated" You can get "modern GPS" with limited modifications But do you want to get rid of your vacuum system? I see you have stand-by vac, Do you want all digital or a hybrid of steam gauge and some digital? Do you want a large flat screen panel? You asked about engine instruments - do you just want redundant digital display or do you want to get rid of you current instrumentation? If so you need a "primary" EDM like a JPI EDM 900 or larger 930 Do you want it all integrated with a modern autopilot? I see you have a WX950 stormscope - do you want storm/lightening on your MDF? - perhaps a WX-500 How much do you want to spend? You really need to look at other panels, find out how much they spent, Also talk to an avionics shop and get estimates. https://www.aircraft.com/aircraft/222336491/n97dm-1997-mooney-m20j-mse Avionics King KMA24 Audio Panel King KLN89B GPS King KX165 Digital Nav/Com with Glideslope King KX155 Digital Nav/Com King KN64 DME with Remote Switch King KCS55A Slaved HSI King KAP150 Fully Coupling Autopilot with CWS Appareo Stratus ESG Transponder with Stratus ADS-B in Equipment WX950 Stormscope Shadin Digital Fuel Flow Electric Pitch Trim Symphony 468 Intercom System LED Wing Tip Strobes & Recon Lights Yoke Ident Button

High cylinder head temperature can be caused by many things unrelated to fuel octane, pre-ignition or knock. You could have high temperature in only one cylinder. You could have an errant temp probe. But you are right that a system could be designed which makes changes or takes action without command by the pilot in order to "save something". And when the pilot realizes why he is losing power, speed or climb he can over-ride it. There is precedent for it in GA with good intentions (automatic action that can be over-ridden by the pilot when (if) he figures it out)- Piper did this with the "Automatic Landing Gear" on the Arrow. I am sure it saved a few gear-ups and retracted the gear many times when the pilot forgot. It also caused many accidents when it happened just as the pilot needed the opposite and the pilot did not realize in time.

Not from the ability to change advance. There is no way for the e mag to know if the engine is beginning to enter knock/detonate conditions due to fuel quality issue, load, mixture, etc. There is no knock/detonation sensor. You are thinking of a liquid cooled automobile engine with a feedback loop that monitors engine noise and can discern a knock or detonation sound signature. No knock/detonation sensor works reliably on an air cooled aircraft engine. Too much other mechanical noise. "In an auto engine, the common cylinders and head make a more metallic or audible sound that is transferred to the entire block assembly. That is why they can use only one knock sensor to control knock in an auto engine." https://generalaviationnews.com/2015/05/27/visser-for-10/ If you have an e mag that blindly retards the engine based on something than actual detonation then you could suffer reduced power just when you need it most. https://generalaviationnews.com/2011/08/29/knock-free/ The e mag might have a hotter spark but I doubt that will help much with low octane knock.

The Registered owner of N9525M is also listed as an A&P in the FAA Airman. The Registered owner was active on MS but stopped posting on MS during May 2023 and last visited MS in February of this year. May not be him flying. Interestingly his ADS-B does not seem to show up on FlightAware or on ADSBExchange since March of this year. Correction: That reference is to the current owner. This happened in 2015 which was with a prior owner. "ATC Live" YouTube Channel (video posted at beginning of topic ) scraped (basically copied) this flight/ATC coversation from The Flight Follower YouTube Channel. Original is below. Unfortunately there is no date of flight in either post.

It’s just continuity - open or closed. Ohms or continuity on your meter

It is possible to repair in some cases. It could be the diaphragm or micro switches. Or calibration. Read below. Otherwise you need a new one for a couple $ thousand. Lasar claims to sell for $900 but not clear if they have any — says “call for availability” and “call to special order”… https://lasar.com/switches/airspeed-safety-switch-656-3-880013-507

Cheaper Lycoming? Compare new Lycoming vs new DeltaHawk. IO-360 is $99,000 from AirPower but none are in stock. I bet you that the new shipment when it arrives is over $100k. https://www.airpowerinc.com/enpl-rt9304 That’s why DeltaHawk is pursuing OEM airframe manufacturers. And that is why Mooney is “dead” to them.

Oh you mean like this “point-of-view in politics” post in a “Fuel Cost” topic on MooneySpace by someone named “Hank”?.. “Also, Kalifornia is busy giving money hand over fist to illegal aliens, and ignoring the citizens from whom the money is taken . . . .“

Don’t you mean that you don’t know of any “that will publicly admit YET”. Funded by Koch Foundation among others. Seriously doubt it or goals are going away. Likely will resurface with a name change. https://www.heritage.org/press/project-2025-reaches-100-coalition-partners-continues-grow-preparation-next-president

Did anyone bother to notice that ATC User Fees are a key goal of conservative agendas, Heritage Foundation, and Project 2025? From Project 2025: “The FAA is the only modern Civil Aviation Authority (CAA) in the world that does not assess fees for its services" "Require the FAA to operate more like a business." ”at a minimum separate the ATO from the FAA” "Shift from aviation user taxes to fees for air traffic services paid directly to the ATO."

I see now that the 3/18/2008 AML does not list any of the STC Holders by name but instead includes a few STC's by Airframe such as those by Rocket Engineering. The Mod Works M20L conversion was STC Number: SA02624AT and the Mod Works VM1000 installation on multiple Mooneys was STC Number: SA01516AT. I don't see either one on the AML. But somehow N823TH, a Mod Works converted M20L has a JPI EDM900. https://www.aircraft.com/aircraft/231785879/n823th-1988-mooney-m20l-pfm

Good catch.

@LANCECASPERis correct that the JPI STC SA01435SE only lists originally manufactured airframes - no modifications. For example the numerous Rocket Engineering K/J mods Rocket and Missile are not listed either. http://www.jpitech.com/manuals/04/900-930 AML and STC.pdf But it does not seem to be an issue. Here is a converted M20L with a JPI EDM 900 (primary instrument) that sold in the last year. I assume he got field approval. So if money is no object spend away. https://www.aircraft.com/aircraft/231785879/n823th-1988-mooney-m20l-pfm I also found a Rocket conversion (also not on the JPI STC AML) with the larger JPI EDM 930 (primary instrument). So it seems prevalent and easy to do if you wish to spend the cash. https://www.aircraft.com/aircraft/220371009/n252ac-1988-mooney-m20k-305-rocket

How many hours/calendar age on the engine? I assume that you have only the screen and no filter on this engine. Have you already dumped the oil? - if not drag a magnet along the bottom of the pail/pan. See if you pick up more bits.