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Thread: Overhaul complete - Cost breakdown

  1. #1
    Orbiting Earth Left the Solar System
    Join Date
    Jul 2004
    Just outside Nawlins

    Overhaul complete - Cost breakdown

    I don't remember which model engine you have. Which one was it?

  2. #2

  3. #3

    Overhaul complete - Cost breakdown

    >Wes K wrote: Hopefully Bob S will weigh in here but I notice a rather
    >unusual breakin schedule for an freshly overhauled engine. Around the
    >patch twice and
    >then around the patch again for awhile is unusual to say the least.
    >Lycoming Service Instruction 1427B explains all post overhaul testing.

    I suggest going with the instructions of the OH shop, as THEY are the ones
    on the hook for the warranty.

    Upon installation, I start the engine and run for a minute or less, looking
    for normal indications on the gauges, and then shut down and inspect for
    fluid leaks.

    Absent any leaks, I re-cowl and launch for an hour of high manifold
    pressure operation, staying close to the airport to always be "in the
    funnel". After an hour of testing above the airport, another inspection
    for leaks, both liquid and exhaust, etc. If all is OK, I suggest following
    the instructions of the OH shop, which in my experience have mirrored
    Lycoming's instructions referenced by Wes.

    The OH shop I use has a test cell and they run and begin the break-in
    process on all their engines, so they know they have started the ring
    seating and have no leaks from the engine. That doesn't absolve the
    mechanic from checking for leaks from the hoses and connections that were
    made during the engine installation, but it does let you know that that
    critical "first hour" has been run under controlled conditions, and you
    aren't as much of a Test Pilot on the first take-off. The shop I use will
    run an extended break-in for the cost of the fuel. I think it is a good
    investment to let it run another couple hours on the stand for the ~$100 in
    100LL that it takes to do this.

    I would question the shop operating the plane on test flights. Does your
    insurance cover them? Do they meet the "open pilot warranty" of your
    insurance? Do they have their own insurance to cover your plane?

    Have they ever flown one of the same model? Or are "all little airplanes
    the same" in their view? Tread carefully Grasshopper.

    Bob Steward, A&P IA
    Lycoming Alumnus, Class of '99
    Birmingham, AL

  4. #4

    Overhaul complete - Cost breakdown

    I know, you didn't have any control over it. But as a warning to others who need to break in an engine... Do not let anything interfere with the full process of breaking in per the engine manufacture's service bulletin. Your guy taking it around the patch a couple of times and landing to let you go finish the breakin was not doing you any favors. Interrupting a breakin flight should only be done for safety reasons. You run the risk of glazing the cylinders and having to hone and rering them despite being overhauled. Get the SB read it and do it your self or insist that the test pilot follow the instructions to a "T", and you should have a proper break in and fewer problems.

    Joe, a mechanic that has seen customers not follow the service bulletin and glaze their cylinders.

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