Shadrach

Looks to me like it held up quite well. Airplanes are not designed for cartwheels. The pax compartment exhibits no signs of deformation. Dude could have opened the baggage compartment and grabbed his luggage..had it not been strewn about the interior.

Don’t be lulled into thinking that speed will be a significant indicator...it won’t. Pitch is a bit different at approach speeds with the gear up. It’s perfectly easy to fly a stabilized descent profile at pattern approach speeds with the gear up. If it weren’t, we’d see less of these unfortunate events. As to the insurance question, my premium has varied up and down by about 15% over the last 10 years. I can’t say that I’ve seen a trend. I actually think it’s remarkably inexpensive given the risks involved.

I don’t think that staight weight oil is a bad idea if you’re able to attain the appropriate engine/oil temperature before start up. You’ll have to excuse me for being a bit dubious on like Lycoming’s recommendation. They also state the following: For most Lycoming models, preheat should be applied anytime temperatures are at 10˚ F or lower. https://www.lycoming.com/content/operating-cold-weather So To be clear, according to Lycoming it’s perfectly fine to crank your cold soaked airplane that’s been sitting for two days at 12°F with straight 80W oil in the case. Does that seem like well considered advice to you?

Very few issues on my end. I think that age and inactivity are the biggest culprits. I am trying to conceive of how multi-viscosity oil mineral oil would cause cylinder problems. What data are you using to form this opinion? is it anecdotal? is there a study or test that shows this to be true? Please expound on this.

Good deal. I am not one of those folks that believes you need an engine monitor to run LOP safely. You're equally in the dark on either side of the mixture spectrum without one. That means it's prudent to run conservatively rich or conservatively lean. The up shot of running conservatively lean is that in the off chance you have an injector issue , you'll feel the engine get rough and it won't put your mixture in a bad place on that cylinder.

You're not going to hurt anything running that way. As I said earlier, there is potential for plug fowling. The only other issue I see is that your using a single probe EGT. That means your using that cylinder (likely #3) as a proxy for all four. While not ideal, I would surmise that your engine's spread is close enough to do it safely given that it runs 125 LOP at low power (to run that far LOP at low power requires very consistent F/A ratios form cylinder to cylinder). That being said, you really want to lean on your richest cylinder when LOP (ensuring the rest are leaner) and on the leanest when leaning ROP (ensuring the rest are richer). You're lucky to have a conforming engine that runs smoothly across the mixture spectrum but that is not a substitute for real data. Also, the 200-250C reference is to plug temperature in the cylinder not combustion temp (which is way hotter at any usable mixture setting). If the plug is below the phase change temp of Lead Bromide, the plug will collect Lead.

Time in service for the overhauled cylinders is unknown. I know it’s anecdotal, but it seems that there’s evidence that suggests that lycoming cylinders are good for single overhaul. That means if I want to be cheap and I ran my engine conservatively during its first run, I might consider overhauling my cylinders when it’s time to renew the engine. Buying overhauled cylinders with unknown history is a bigger gamble, much more so if they’re going on a low time bottom end. New Lycoming cylinders tend to go TBO and beyond on a NA lyc 360s baring the odd installation mistake or abusive engine management. How is it that we have no idea about the other three cylinders? He has an engine log just like the rest of us. I know that my engine had four factory new cylinders Installed at overhaul 19 years ago. They currently have about 1300SNEW. The OP stated that his cylinders have 500 hours on them but didn’t state whether they were factory new or overhauled at the time of installation. This would be good to know. It would certainly affect my decision making process. If they’re all overhauled cores with unknown history and two are not repairable, I’d consider topping it with four new lyc cylinders with the hopes of running them for at least the next 2000hrs.

Are you referring to the the fuel tanks? I beleive that is the only aluminum in the wing. Do you have pictures?

A walk around will only tell if the belt is very loose. Perhaps some hands are more calibrated than others but I don’t trust mine. One really needs to put a torque wrench on the pulley and verify it slips in the proper range for a new or used belt.

Thanks Jim. It’s interesting to note that Lycoming minimums are not very realistic and sort of contradictory. Can you imagine any practical scenario where an engine with CHTs in the mid 100s producing an oil temp anywhere near 165? Mike Busch says the following about low CHTs: You caution against excessive CHTs, but is it possible for CHTs to be too cold? Yes, it's possible to run CHTs so cold that the tetraethyl lead (TEL) in the 100LL is not properly scavenged and starts creating metallic lead deposits in the combustion chamber and lead-fouling the spark plugs. However, in most engines, it takes verycool CHTs (down in the mid-200s °F or lower) for an extended period of time (hours) for this to cause a problem. We usually see this problem in airplanes used for fish spotting, pipeline patrol, search and rescue, and other "loiter-mode" operations. Unless you fly at very low power settings (e.g., 50 percent) and/or at very high altitudes and very cold OATs (e.g., FL240 and -30°C), it's not usually a problem.

I would be interested in its compression check history. Obviously it passed many annual inspections but did it give readings in line with the other cylinders? I’ve heard enough stories of engines being assembled with rings missing or incorrect rings but I’ve never actually seen it first (thankfully) or second hand.

@mschmuff - I’m really sorry that you’re dealing with this but I am releived that we didn’t do one of the flight we discussed prior to the failure. Has anyone diagnosed that likely cause of the failure? Both preignition and detonation can cause ring failure, but both of those events would come with significant heat (CHT).

It does not. These pistons are not symmetrical. #4 is oriented 180° from #3. #3’s tendency to be hottest is due to the rear baffle seal abutting the non-finned side of the cylinders head. #4 does not have the problem because it’s revesed and the fin side abuts the rear baffle seal.

Why would a factory reman be a solution to cylinder infant mortality?

Mooneys can be a pain to work on. Older vintages even more so. There’s not a lot of room/access on either side of the firewall. This can mean that certain repairs require disassembly of additional components. It can also mean lying in a narrow footwell on you back working with your arms in an uncomfortable position. There are also lots and lots of fasteners to contend with. If you spend time working on one, you get to understand the cost associated with maintenance labor. The best way to mitigate this is to find an experienced Mooney mechanic. Mechanics without Mooney experience can sometimes waste a lot of time trying to remove something from a crowded cowl without removing other items that make the job easier. Brand C and P products are not as compact. Cannot speak to how Beech compares.