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Hi! I hope this will help other Bravo owners who struggle to run the TIO-540-AF1B at Peak or LOP TIT. But first, in full disclosure I am not an A&P and this is not advice. I am simply illustrating my experience with this engine, and it or may not apply to you. Always follow the POH when you are not sure that your deviation from that document is in your best interest. I am a lean of peak fan, always have been. It comes back from my days of working on non-aircraft internal combustion engines and proving that an engine run LOP operates cooler, cleaner and lasts longer than a similar engine run ROP. I have taken the Advanced Pilots Seminar course on advanced engine management http://www.advancedpilot.com and had numerous discussions with Lycoming engineers, the folks at GAMI and engine builders, and I have used this knowledge to come to a few conclusions about this engine that I would like to share. I am not poking the sleeping “ROP vs LOP” dog. :-) and I realize that Lycoming - in some instances but not all - does not recommend operating LOP. I also believe that if they could, they would revise that language to say: If you have a good engine monitor, tuned injectors, and a knowledge of how your engine operates, you should run LOP whenever your heart desires - except on take off. My opinion is that Mooney, when they introduced the TLS, continued their fine mission to make the fastest commercial SE piston airplane. To do this, they needed a lot of power -and- in a weight package that would not cause the flight envelope of the long body to get too forward on the CG, the TIO-540 was the answer. Bravo owners know that the airplane is already pushed forward CG and many have Charlie weight for aft ballast installed (which lowers the already skinny useful load). The TIO-540 is a complex high performance engine and should not be grouped with most other ground boosted engines for performance discussions, The reasons for this, IMHO, are due in part to two things: 1) a complicated (but effective) turbocharging controller system, and 2) the requirement that the engine runs at very high percentage of power levels to make book speeds. I did a post a few weeks ago on the Bravo’s power percentage here. Because this engine is normally operated at greater than 80% power during cruise by most people, this engine is very working hard and making a lot of heat for a lot of the time. It is also doing so with rather loose factory tolerances on the precision of fuel flow to the cylinders which makes it extremely difficult to run this engine in an wide and efficient range of power settings. The POH states only two settings: 1) ROP TIT by at least 125dF for “best power"; and 2) Peak TIT as long it’s below 1750dF (1650dF at high altitudes) for “best economy" - the latter is sometimes impossible to achieve with this engine at higher power levels (30” MAP and above) because of poor fuel distribution which causes engine roughness. When near peak TIT (or EGT) the roughness is normally due to some cylinders running leaner than others. The leaner cylinders produce less power than do the richer cylinders which give you the impression that there is something wrong because you feel that power imbalance as roughness. (Note: that slight roughness is not a bad thing, your engine won’t fly apart, it really doesn’t care, only you do.) Spark plugs play a key role in this too - more on that in a bit. Here’s the rub... Because most of the TIO-540-AF1Bs have unequal cylinder fuel distribution, when Bravo owners try to run the engine per the Sun Visor chart at Best Economy (Peak TIT) they may find an disconserting “roughness” and feel a slight loss of power. That combo causes some consternation, and when that happens, some operators I’ve spoken with will simply dial the Bravo’s red knob in just a little richer and go slightly rich of peak TIT just enough to cure the roughness. Thinking that they are now 'just fine’ they fly the engine at that setting - when in fact they are not “just fine." They are now operating the engine “slightly ROP TIT” at a mixture setting that causes the most cylinder head heat, the highest internal combustion pressures and at a place where the engine can easily begin to exhibit detonation. (See graph below, which was taken from the Lycoming Flyer publication) The Mooney POH does not say it is OK to run the engine “slightly” ROP TIT because both the factory and Lycoming know that is a very bad mixture setting. All of the experts I’ve spoken to agree that no internal combustion engine should be operated “slightly” (10-60dF) rich of peak. If you can’t make Peak TIT for whatever reason, better to just go greater than 80-100dF and accept the extra fuel costs and keep things in the engine cooler and happier. I have not found anyone who disagrees that sustained high heat weakens, fatigues and shortens the life of the metals used in engines, and that’s why we see all kinds of advice about keeping cylinder head temps below 400dF. The Bravo’s POH advises that you use a combination of gauges when setting power - TIT and CHT as the most prominent. The POH also says that the CHT redline for this engine is 500dF - which everyone (experts or not) agrees is simply ridicules. If you have an older Bravo, and especially one where a field AF1A to AF1B conversation was done, you may want to check to see on which cylinder the panel’s CHT temp probe is located. The AF1A probe was located on cylinder #5, and Mooney Service Instruction M20-101C states that it should be on cylinder #3 for the AF1B. Check yours, especially if you rely on the single panel CHT gauge, I’ve spoken to three Bravo owners where the CHT probe was still on #5 (mine was too). There is a big difference in the cooling between #3 and #5 - #3 being as much as 50dF hotter. That all said, in summary the TIO-540-AF1B is a hot running, high power, high performance engine, different from many others. In the M20M it is asked to operate at the top of its performance range in order to make POH (book) performance numbers, and us Mooney drivers like to go fast! Adjusting the mixture on this engine can be tricky due to engine’s generally unequal cylinder fuel distribution and, in many cases, the wrong type of spark plug being used. I wanted my Bravo to act like most other well-tuned and instrumented airplanes I’ve flown. While always keeping the cylinder head temps below 400dF, I want to be able to safely set the engine for maximum power when I want to go fast, and I want the ability to safely save fuel when fast doesn’t matter as much. I don’t want complicated instructions to do this, and I want to feel as if the engine is happy and smooth no matter what. Before I started this trek, I could not run my Bravo at Peak TIT at MAP higher then 29” without noticeable roughness and/or what I felt was unacceptable power loss. And there was no way this engine would run LOP. I would flow about 22 GPH of fuel in cruise at 100dF ROP TIT (on hot days I needed to to be richer to keep the CHTs below 400dF). Here’s what I did. I first ensured that magneto timing was correct. This is very important with high performance engines; you can often get away with inexact timing on lower power engines, but never on engines like the TIO-540. Mine were pretty close, but not exact - they are now. I had new Champion massive plugs installed about a hundred hours earlier, on inspection they looked okay and they passed the tester test. We gapped them at .016. I installed a new set of GAMI TurboInjectors. When I spoke with the factory rep John-Paul he cautioned me that this engine was a hard tune and that I should expect to have to work at, and that there might not be the success that others have with GAMIs on other engines. I love honesty - these guys at GAMI are true pros. The first set of injectors made a marked and clear difference. I was able to run at Peak TIT smoothly for the first time, but I was unable to run LOP without roughness. I did a GAMI lean spread test and found that my spread was about 1.4GPH, while better, it was not ideal. I contacted the factory and John-Paul immediately sent out two replacement injectors for a better match. After that a test flight or two it showed that I actually picked up about two knots at peak TIT and fuel flow was down a little. I could now get a little bit LOP with a GAMI spread of .9GPH. Also noticed CHT were generally cooler by about 20dF. This was due to the fact that the better fuel distribution was allowing all cylinders to run more equally, so at Peak TIT all cylinders were closer to their peak EGT. Fuel was saved for the same reason - unnecessary rich cylinders were now leaner for any given mixture setting. Because this engine seems finicky at different MAP/RPM settings, I decide to tune to a specific sweet-spot for the GAMI spread - I picked 29”/2400 for this as it is, according to the Lycoming power graphs, about 75% power on a standard day, at mid altitudes. This might have been the most important step I took in achieving success with this tune, on this engine to allow for good LOP performance. I sent the new GAMI lean test to John-Paul - not satisfied he sent me a single replacement for the one cylinder that was off a bit. (no charge for all of this and no questions asked). We installed that one injector and then did a test flight. The biggest change was that I could get more LOP without roughness, at 2400/29” I could get to about 20dF LOP. I would lose about 9 knots, but I was able to save almost 6 GPH of fuel. While I still couldn't get much past Peak TIT at higher power setting I was happy with the trade off; now I could achieve both fast and efficient settings. My GAMI lean spread was now a very comfortable .3GPH as you can see from the graph below. I thought that was all I needed to do but it wasn’t ... I have a Savvy Aviator account, I upload my JPI engine analyses data there, and I happily buy their yearly analysis service. I uploaded a flight and was looking at the graph and saw something on one of my lean spread tests that I could not understand. During a lean test, you should see all EGTs rise as you get leaner and leaner, then they should all peak (at slightly different times, that’s the fuel flow “spread”) and then they should drop off. On my test, there was a second peak? I submitted the flight for review at Savvy and Paul Kortopates wrote back and explained it, and as soon as I read his explanation I understood: He said "That second "peak" is actually what happens when the mixture goes lean enough to fire only one plug. You are seeing the same rise we would see if you switched off one of the magneto's so that there was only one plug firing- which is what we're seeing here. On one plug alone, combustion is slowed and therefore when the exhaust valve opens we are seeing more of the combustion event and the associated higher EGT because of it” That’s when we discussed the last step I needed to take to get this whole project right - new plugs - but specifically fine wire plugs. It seems as if the fine wire plugs work better than the massives in two instances 1) older wet and oily engines (not the case here) and; 2) in lean mixtures. They’re expensive, about $80 a shot, but they also are suppose to last hundreds of hours longer. After researching both Champion and Tempest, I opted for the Tempest Fine Wires and installed 12 of them. Paul was right on! From the moment I turned the key I could tell that something was different. The engine started better and ran smoother on the ground and in the air, and I am now able to run LOP at 32” MAP and below if I chose. My CHTs are generally 30dF cooler than when I started this project, and I am saving fuel at every power setting. Where I use to run 22GPH at 2400/32 ROP, I now run 20GPH with the same airspeed, and if I want to throttle back to 2400/29, I loose about 10 knots and run about 15GPH at about 20dF LOP. In all, I have about $2500 invested here, but in fuel savings alone that will pay back in short order and then keep paying back. The big benefit is that I have more power options now with the aircraft and my engine will be much cleaner with less carbon deposits on the heads, the values, the plugs and the exhaust system. My flight profiles are not religious LOP, and yours don’t have to be either to get a benefit from the cleaning and cooling aspects of running your engine with a proper mixture, which, for me includes LOP at times. Typically I will run lower power and LOP in tail winds of any speed, because why not? If I loose 10 knots true in LOP but I make up some or all with a tail wind, I’m saving 5-6GPH of fuel AND cleaning the engine as I go. Thanks for reading! I attached some pics - happy to try to answer any questions. Dave

So according to page 2 of the Savvy flight test profiles the GAMI spread flight test on a TC engine is supposed to be run at or below 65% power AND at an altitude where ambient pressure is equal to the MAP (so basically the engine is turbo normalized). So, being the chicken that I am, wanting to do the lean test at 55%, I: - assume ambient pressure is ~30" (QNH) at sea level and changes -1" for every 1000 feet (from the Saavy doc) - look at page 5-20 of the POH and see that for 55% power at 2500 RPM and 6000 feet the MP should be ~24" (30-6) - start leaning, while adding a little MP as it drops (no auto wastegate), then richen, while reducing MP, repeat 3+ times, do LOP mag check If QNH is 32, a high pressure day, I'd need to go up to 8000 ft, if it was 28, on a low pressure day, 4000 ft would have been appropriate, correct? Anything I got very wrong? Anything I am missing? 5-20-rotated.pdf

I am a past owner (850 hours then sold in97) of a 1979 M20K with a GB engine with intercooler. I am trying to get back into flying and have been looking at the M20K. I would like to hear the opinions of pilots that owned and fly the K with a GB engine. All the talk I hear is negative about the GB engine. The Mooney I am presently looking at has a GB engine and none of the add-ons.

1979 Mooney 231 M20K Asking $75,900 I am selling it because I usually just fly the cub around, I bought this to go places and with work have been very unable to go anywhere. I have owned it for just over a year and put a ton of money into it; bought it out of Alabama with a Mooney center clean bill of health; needless to say our Mooney expert thought otherwise, plane is perfect now and ready to go. Any question you can call or text me at 203.903.3759. Paint is 7/10 (removed big escape sticker from cargo door and found to be the old paint under it) Small chips on wing looks great from 10 feet Interior is 3/10 (front seats are ripped, head liner needs to be replaced) Priced Accordingly estimated repair was quotes at $3800 for all new plastics and leather seats Located at KDXR ~5080 TT/ 620 SMOH / 620 SPOH (Has damage history) Annual due June 2018 IFR Due Sep 2017 (will be sold with fresh cert) Engine Compression is 72/73/72/72/72/72 Meryln Wastegate Turbo Plus Intercooler Gami’s Injectors All new fuel system ( 2017 Annual) Lines, mechanical and electric pump, fuel manifold Baffeling redone (2017 Annual) New exhaust (2017 Annual) New Starter Linkage/ Starter (2017 Annual) New Alternator (2017 Annual) Rebuilt Mags (2017 Annual) Airframe Precise Flight Speed Brakes Monroy Long Range Tanks (104 Gal) New Shock Disks (2017 Annual) New Main Gears both sides (2017 Annual) New Brake lines/ rotors/ pads (2017 Annual) New Gear Motor with throw back spring/clutch (2017 Annual) New Gear Linkage (2017 Annual) New inner gear doors and Spats (2017 Annual) M20R steering horn and front Gear *HD*(2017 Annual) Gears Rigged (2017 Annual) Whalen Strobes (std wing/ LED Tail) (2017 Annual) Oxygen Tank Hyrdo June 2016 (4 Place oxygen factory) Oxygen Tank Pressure compensator July 2016 ($8k) ¼” Glass all around New door and window seals (2017 Annual) New Gas Cap O-rings (x4) (2017 Annual) New Landing light lens (2017 Annual) Avionics Sandel SN3308 HIS Guardian Backup Vacuum Garmin 430Waas JPI JDM700( all new probes (2017 Annual)) JPI Fuel Flow Monitor KX155 with Glideslope BFG WX1000 Storm Scope KMA 24 audio Panel King KT76a transponder Century 41 Auto Pilot with Go around (requires GPSS to interface with Sandel) flight computer and attitude indicator fresh overhaul in august. Horizon Digital Tachometer (2017 Annual) Extra's Comes with Cover, Tow Bar, 2 x Oyxgen Cannulas See below link for a detailed report of the accidents and history on this aircraft Aero-space Report N231PG Accident record.pdf N231PG Avionics.pdf N231PG Airframe.pdf N231PG Engine.pdf N231PG Propeller.pdf

Great new youtube video on how to manage mixture and fly LOP and ROP: The most information dense filled video on the topic I can remember seeing in some time. The only real thing I would offer to add is Gami's recommend tablel on both how far to be LOP and ROP for any percent power; available here: afms gami injectors rev ir.pdf Incidentally the GAMI FAA approved mixture management is excellent guidance regardless of whether or not use Gami injectors or even if your not fuel injected. Its just that without good mixture distribution (<=0.5 GPH gami spread) an engine won't be able to fly very far LOP, if at all LOP (i.e. where all cylinders are LOP). But virtually any IO-360 can and most of the higher performance Continentals can but may require a little help. But otherwise Martin does a great job of both communicating and illustrating a wealth of information on the subject matter.

Hi all, I am a proud new owner of a 1980 M20K 231. A bit more than I need, but I hope to grow into it. I have been reading this forum as a guest for a while and have just signed up to hopefully get some answers from some experienced and willing people. Keep in mind, I am very green. This is my first airplane and although I started flying over 10 years ago I have only been licensed for a couple years. So still learning lots, and trying to read as much as I can. Just a quick run through: I have the TSIO-LB360. It is at about 1000 hours SMOH and was taken apart in 2013 due to a prop strike but I don't believe anything was replaced. It has the Merlyn Wastegate, an intercooler, an EDM700 engine monitor and GAMI injectors. I also have a Shadin Fuel Flow indicator. First question should be a fairly quick and easy one. I flew with some passengers for a couple of hours. Arriving at my destination I had to overshoot the first approach and when I selected the gear up, it wouldn't go up. After cycling it a couple of times with no response I checked the circuit breakers and noticed the "Gear Act" breaker popped. I tried resetting it, and it popped again immediately. Luckily I am old enough to know not to keep trying like I would have in my younger days :-P My rear passenger noticed that the safety latch (metal cover) was open on the emergency gear release so the handle was exposed. I guess one of the rear passengers knocked it with their foot. I closed it, then reset the breaker and everything was back to normal. I assume that they are interlocked? I have done a couple flights since and there have been no issues. Everything functions normally. I can only assume that was the only cause and I don't have anything to be concerned about? Input? Next question should be reasonably simple as well. When I bought the plane the gear warning horn did not work. We had the manifold pressure all the way back (at altitude) and were not getting anything. Before we finalized the deal, the mechanic adjusted it based on some throttle position/manifold pressure readings which we took during the flight and he fixed it perfectly. It would come on at exactly 14.9" of MP. Except that later in the flight it came on slightly less than normal cruise power settings. It would go off eventually if the throttle was moved in and out, and sometimes if I wiggled it side to side gently or twisted the knob (it is not a vernier) it would also go away, but not always. This is somewhere in the 20-26" range so just below normal cruise I guess. I notice it on descents or in the circuit more than anything. Is this an easy fix? I was told that a Mooney expert from Tri City Aero in Kitchener Ontario frequents this forum and may be able to give me some input. I am just in Burlington and plan to give him a call soon to start our potentially long and expensive relationship The last question I have relating to LOP operations may spark more debate (given all that seems to be out there on the topic which has been beaten to death) and probably has no simple answer but I am just looking for a bit of input, not something complicated and I will do some more research myself. Just trying to figure out where to start. My instructor told me to run ROP with TIT up to 1500. I have seen lots in favour of running LOP so I have experimented a bit running LOP. A couple days ago during cruise at 28" I pulled the mixture back to just under 9GPH. That's where it starts to run a bit rough. I bring it back up to about 9.5 with a TIT of around 1450-1500 or so. I have been told, and gotten into the habit of monitoring TIT closely, but have recently read an article that swears by leaning according to CHT. I do know that CHT's are even more important and have a very close relationship with ICP. Here is what happened. After only a few seconds... maybe 15-30 (I wasn't paying super close attention), my #4 cylinder CHT skyrocketed quickly. On the JPI the middle bar that separates the CHT and EGT appeared to be flashing or basically just started going up and up. Then I got the flashing indicator for that cylinder and the display stayed there and I think the temperature was in the 420 range. I panicked and enriched the mixture quickly and everything went back to normal. I thought maybe I was too lean, and tried it again paying closer attention to things, and the same thing happened. It seemed to happen in less than 10 seconds. What I am looking for from some of you experienced guys is the answers to some of these questions... Is this a sign of pre-ignition or detonation? Is this a bad fuel injector? Do you think I caused any damage in those few seconds that it ran like that? Could it be a bad sensor? Is this a result of running LOP? I can only assume so since it doesn't happen when I run ROP (about 1400-1450 TIT and 11.5-12GPH) Any input on this would be greatly appreciated since this is worrying me quite a bit. I know there is likely more to it than a simple explanation but I appreciate any information that anyone is willing to give. Thanks in advance and I hope to be able to post here and look forward to being part of this community. I just love my plane!

Wondering what suggestions I can get on this. A little back ground first. '78 M20J 201 IO-360 ~1500 hours SMHO fly ROP per POH cylinder #3 plug fowled out a week ago (see picture) all new plugs and now I am seeing Cylinder 3 EGT highest and CHT lowest (see pictures) in all phases of flight. Oil consumption, maybe a quart every 6-8 hours and all oil analysis come back with excellent results. I am thinking bad injector and going to Gami. Thoughts and comments much appreciated.

I have read a lot of post on the forums that mention swapping fuel injectors to help with EGT and GAMI spreads. I have not seen an overview of the process from ground zero. As I have read some of the threads it seems as simple as swapping the high EGT injector with the low EGT injector. As I read more it seems like there are contributing factors to EGT discrepencies such as induction leaks, probe placement, spark plugs and fine wire spark plug cables. I asking this because my plane is going in for its annual and would like idea of what questions to ask before having them swap injectors or if I need to at all. I have a 82 J with a EDM 700, FT 101 fuel flow indicator and GAMI injectors. My FT101 appears to be almost .5 GPH off indicating a higher fuel burn but I have a few result of flights I can share. Flight #1 5500 MSL, 24" MP, 2400 RPM, 9.4 GPH LOP. #1 1421 356, #2 1407 321, #3 1360 308, #4 1425 333 Flght #2 7500 MSL, WOT 22.5"MP 2500 RPM, 9.5 GPH LOP, #1 1417 352, #2 1408 326, #3 1348 290, #4 1447 343 The best I can tell so far my GAMI spread is between .2-.5, I'm still playing with it but my feeling is .3, but is that possible wth almost 90 degree difference in EGT's. The order in which the cylinders peak is #2,#3,#1,#4 After I get the EGT's figured out I'm going after the CHT's Any advice is appreciated.