yes there is, but it is not a set number. it depends on what has to be done at overhaul. there is only so much that can be taken off the crank journals, and the cases. but not every overhaul requires a crank to be turned or a case to be decked. I have a crank on the shelf that was prepped for the second overhauld on the engine and it is still a zero/zero crank. only needed to be polished both times. so the answer is there is not a set amout.
Technically, an engine by serial number can be overhauled or rebuilt an infinite number of times provided all the parts meet the required specs. If an individual part does not meet those specs then it is replaced as part of the overhaul. So regardless the number of overhauls the engine still meets the required specifications.
No. As there is no life tracking of most individual recip engine parts they are all on condition when it comes to replacement. So there is a good possibility there are many individual parts that maybe on their 10th or 20th overhaul cycle. Even in a factory rebuilt engine that comes with a TSN: -0- logbook could have used parts that meet new tolerances.
No. All new.
Pay attention. You asked:
And when you look at the list of engine models the OEMs make, then realize that many of those get produced in tiny numbers per year---like two or three engines or maybe none at all--you see that they can't hope to sell them at the price of a car's engine that might have been built in Asia at low labor rates, or in North America by automated machinery. The popular Lyc O-360, for example, comes in 74 models. And that's just the carbureted versions. I count 81 versions of the IO-360.
Why not? At one time that was the way things were done especially with tube and fabric aircraft. I doubt you'll find very many Stearmans with original metal. As long as you started with a piece of the original primary structure you could/can repair the entire aircraft from that. Then there is building aircraft from salvage or scrap that is still valid except they changed the requirements if you want a standard airworthiness certificate issued. So as you have personally seen with your T-craft, it is a perfectly acceptable way to keep these aircraft flying legally.
Oh, I know, and personally have no problem with it. The old joke is, "jack up the data plate, slide a new airplane under it, and lower the data plate into place." The FAA isn't thrilled when the data plate is the only piece of original metal, though they usually look the other way.
Not really. They’re simply not thrilled when someone doesn’t follow the rules to slide those new parts under the data plate. For example, there are a number of STCs/field approvals out there that allow moving data plates to new parts. Plus the FAA still allows building aircraft from surplus and spare parts. Unfortunately it’s the increasing numbers of people who don’t follow those rules that cause all the issues for the legit installs.
In my experience, its not so much as “looking away” as it is very hard to find and catch these operations. Usually it takes an accident or a disgruntled buyer to find these illegal aircraft. Matter of fact since the 90s there has been a concerted effort to weed out people who wish to swap data plates/histories solely for personal gain. For example, 20 some years ago they added more requirements to get a standard AWC for surplus/spare part aircraft and in 2018 issued Order 8100.19 to stem the increase in “illegal” repairs. However, neither effort prohibits such work performed under the existing guidance.
Im not familiar enough to say but a thorough log book exam should tell you? This stuff should be in the engine log, right? Has the crank been turned down and how much? When were the cylinders last changed? I dont think they ever bother to bore them over and use over sized pistons, right?
Depends on who performs the work whether the detail is listed in the logbook or on a work order like used in a CRS. In a number of cases you'll only see an logbook write up stating installed overhauled engine assembly.
No. A number of items can be resized depending on the engine. The more common are cylinders/pistons/rings which can be oversized generally between .010"-.030"
Im learning. What part gets decked and why? Where the cylinders bolt on?[/QUOTE]