I currently have a 172K. Very well taken care of. As far as I know, its the original engine from 1969. Engine and Airframe time is currently 2300 hrs. Compressions are good, no metal in oil, and doesn't burn too much oil. Every mechanic I talk to says, "DON'T MESS WITH IT. Run it til it tells you it needs an overhaul." I stuck an engine monitor on it to keep a closer eye on things, and I am a happy camper.
I really appreciate the part about not over reacting to a bad oil report. I have an automobile engine that made some pretty good metal for 2 or 3 changes at 225k miles. It stopped and has had clean oil since. 310k now and still running strong.
I specifically remember a Shell Oil advertisement, I think in Flying Magazine, that recommends a 40 min a week run of an engine for long term health. They did not mention water but they said the engine should be at operating temps.
After a week or two of not oil circulating, the parts start losing the oil cover by gravity. Rust start forming on those parts. Then that rust, which is like sand, gets circulated around the engine on the next late startup. That "Sand" will wear off parts. The area that got the rust gets worn out too. You have to warm up that engine at least once a week. I cover the exhaust and intakes when not using it for one week or more.. Maintenance is a money saver..
Unrelated to aircraft I was involved in caring for and feeding of industrial process control systems that had regular maintenance PMs on instrumentation calibration. The interruption to production coupled with maintenance tech errors (mis-calibration, damage to instruments, wiring not connected back up properly) was a far greater impact than leaving the instruments alone. I completely got rid of some calibration PMs and changed some others to spot check that could be run at the control system console without ever touching the instruments in the field. Failures dropped virtually to zero, and in critical applications I set up the controls to default to a safe state upon an instrument failure and logged an alarm to the systems.
The only issue with running over TBO is the apparent value of the aircraft plummets if the engine is either high time or 'runout'. An aircraft with a low or mid time engine will have a much higher perceived value.
I don't doubt most of the logic here, but the statistics are a little funny. There are fewer planes flying with high hours / older engines, so of course the number of accidents involving those planes will be less. The data has to be normalized - each bar should be a percentage.
How do you value an airplane that’s at TBO? That’s in great condition and checks out? Say for example a 1961 Cessna Skyhawk or 1976 Beechcraft Sundowner with 1800 hours? If I follow this advice to ignore the TBO as far as engine tear down. Clearly I can still use the TBO to subtract from the asking price? Right?
I have found over and over that the mechanic is generally responsible for most of the mistakes that cause problems with the airframe and the engine. They are either in a hurry to make that money and get to the next job, or unfamiliar with what they are doing, or distracted, or a number of other reasons. In my experience I find that it is best, if possible, to go behind everything a mechanic has done and gingerly fly that airplane near the airport for at least a few hours after any mechanic work including Annual Inspections and any engine work that requires removing parts more than spark plugs, oil filters and oil and even then personal inspection is a good insurance policy against "landings" that you really don't care to do.
I suggest that you quit flying aircraft. You would think differently, having an owner on your ass to finish the maintenance work now!!! You"re ignorant of work skills required by the FAA.
TBO is a conspiracy to keep A&P's rich! LOL!!! I personally feel that until the Comp ratio is at or lower than 65 +/- 15% in all cylinders the engine is good ta go!
It’s crazy that engines get overhauled for cylinders you can buy new ones on aircraft spruce for 900- 2000$ if it’s 22,000$ to overhaul/replace a 4 cylinder engine you’re just burning money. For an O-360 it’s 4800-5500 to replace all 4 cylinders
dra gon I’m guessing, I looked at the price of cylinders on aircraft spruce which come as a individual replacement kit with all the seals. They range in price from 800-2000$ and I don’t know the part number for the right one so I assumed it was somewhere around 1300-1600$ each since an O-360 is kinda a middle of the road engine between the O-200 and O-570
It's not just the cylinders, though. if you want to overhaul you'd need to also look into getting a new crankshaft and camshaft, gearing, etc. those cranks and cams are where the real money is.
looking at a 2001 piper practaly new with 1048 hours but the engin was not ran for 3 years it was only ran about 1 hour a year for thoes years would it be safe to say its ok i hear not running them is bad from sitting
after a week or two of not oil circulating, the parts start losing the oil cover by gravity. Rust start forming on those parts. Then that rust, which is like sand, gets circulated around the engine on the next late startup. That "Sand" will wear off parts. The area that got the rust gets worn out too. You have to warm up that engine at least once a week. I cover the exhaust and intakes when not using it for one week or more.. Maintenance is a money saver..
