Home 2024 Forums Opening Section Maintenance Issues Cracked Case

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  • #83724

    Well crap… Airplane just went in for annual and the only major squawk I had was an oil leak on the right side that started just a few hours ago. I received the dreaded phone call and turns out it’s a case crack.

    Crap.

    I believe it’s in the “critical” area, so the engine’s coming off and heading out for a case repair. $20k+ later and 6-8 weeks from now I should have a flyable airplane. While the cost hurts, the time down is just as painful. I use my airplane a lot and this is already screwing up two trips that are difficult to fly commercial.

    The engine has around 1,100 hours so I’m planning a repair instead of an overhaul. The $40k delta for an overhaul doesn’t make sense to me at this time.

    Robert

    #95712

    Robert, that sucks!

    Where exactly is the crack? Do you have pics? Anything different around the time you first had the crack? Fast descent, very cold temps aloft, etc. Are you the -L engine or -N?

    Eric

    #95716
    quote EPANNING:

    Robert, that sucks!

    Where exactly is the crack? Do you have pics? Anything different around the time you first had the crack? Fast descent, very cold temps aloft, etc. Are you the -L engine or -N?

    Eric

    Crack is between 1 & 3. Very hard to see, but it’s there – About 2″ long and when we pressurized the case oil and air came out.

    Based on the oil on the engine it looks like it happened about 15 hours ago. I had one cold start in Taos (airplane was in the hanger for several hours, but they didn’t plug me in like I asked – Left started fine, right took a bit longer) but otherwise very normal operations. I have a sneaking suspicion the problem happened there, but I can’t really confirm. No way to correlate if the cold temps (not that cold really) caused the issue.

    Everything I’ve read says that, barring a prop strike which I haven’t had, there’s nothing pilot controllable about a case crack. Bob T. had a very similar thing happen to him and wrote about it a while back.

    Welcome to airplane ownership.

    I’m electing to fix the crack and will end up with a 1,100 hour engine with a new bottom end – Should run well past TBO with a few new cylinders, but of course won’t be an “overhaul”. If I were selling soon I’d get an overhaul, but I’m not planning on it so we’ll fix the crack and keep on trucking.

    The 421 is an expensive beast to fuel and fix, but nothing can touch her when you consider the operational cost and capital invested.

    Robert

    #95717
    quote RCJOHNSON:

    quote EPANNING:

    Robert, that sucks!

    Where exactly is the crack? Do you have pics? Anything different around the time you first had the crack? Fast descent, very cold temps aloft, etc. Are you the -L engine or -N?

    Eric

    Crack is between 1 & 3. Very hard to see, but it’s there – About 2″ long and when we pressurized the case oil and air came out.

    Based on the oil on the engine it looks like it happened about 15 hours ago. I had one cold start in Taos (airplane was in the hanger for several hours, but they didn’t plug me in like I asked – Left started fine, right took a bit longer) but otherwise very normal operations. I have a sneaking suspicion the problem happened there, but I can’t really confirm. No way to correlate if the cold temps (not that cold really) caused the issue.

    Everything I’ve read says that, barring a prop strike which I haven’t had, there’s nothing pilot controllable about a case crack. Bob T. had a very similar thing happen to him and wrote about it a while back.

    Welcome to airplane ownership.

    I’m electing to fix the crack and will end up with a 1,100 hour engine with a new bottom end – Should run well past TBO with a few new cylinders, but of course won’t be an “overhaul”. If I were selling soon I’d get an overhaul, but I’m not planning on it so we’ll fix the crack and keep on trucking.

    The 421 is an expensive beast to fuel and fix, but nothing can touch her when you consider the operational cost and capital invested.

    Robert

    You might want to check prop balance and check the starter adapter dampener but I agree little you can do. How many hours on the case? Are you doing anything with the cylinders while they are out? Exhaust valve, cylinder hone, or rings?

    Eric

    #95718
    quote EPANNING:

    How many hours on the case? Are you doing anything with the cylinders while they are out? Exhaust valve, cylinder hone, or rings?

    I’m reworking 2 cylinders (one’s at 10, the other 50 – Neither are leaking in flight and I would not have pulled the 50 if the engine wasn’t coming off, but since there is effectively no labor charge it’s worth it), but otherwise not doing anything. We’ll look at the exhaust, turbo, etc, as we normally do, but I don’t see the need to rework everything in the engine case.

    In the 210 when you pulled an engine it was the only chance you had to see a lot of things in the engine case – Not so in the 421. There is SO much more space in the 421 engine compartment than a 210 (and even compared to a 340 or 414 surprisingly) that you can get to stuff to inspect/replace, etc.

    No clue how much time is on the case – I’ll look it up next time I get a chance to cuddle with my logs.

    Robert

    #95723
    pmcnamee
    Participant

      I like to sleep well at night not worrying about the future.

      Factory overhaul exchange with full warrantee is the only thing I would except on a GTSIO. I have been down the repair road too many times. That is a big expensive, important engine to be putting a bandaid on. It has never worked for me financially over the last 35 years, and I have seen it more than a few times.

      Call Air Power, Inc. Continental Engines has some special programs for troubled engines like yours on exchanges.

      No one knows more about those engines than the people who designed, built, and guaranteed it.

      Good Luck and keep flying safe.

      Pat

      #95726
      quote PMCNAMEE:

      Factory overhaul exchange with full warrantee is the only thing I would except on a GTSIO.

      A fair point, but the $40k delta just doesn’t make sense to me at this point.

      The last time I had an engine issue I made the opposite choice and went for a RAM exchange instead of splitting the case and repairing it… This time I’m going with a repair.

      FYI, unless you get a factory NEW engine (not an overhaul) there’s no guarantee that you get a new case. There’s no reason that if I sent my cracked case back to TCM to exchange it, it wouldn’t show up on another engine at some point (repaired, obviously).

      We’ll see how it works out!

      Robert

      #95732

      I also will go for the “New Engine” choice next time, we found a small crack in the case of the right engine on our 421B,{ Almost at TBO} went for a Ram rebuilt engine, tweny hours later it self destructed on approach ln less than ideal conditions, then the “fun” trying to get service and real suport started, a very unpleasant experience, so never again, factory new from now on.

      #95733
      quote RLORETTO:

      I also will go for the “New Engine” choice next time, we found a small crack in the case of the right engine on our 421B,{ Almost at TBO} went for a Ram rebuilt engine, tweny hours later it self destructed on approach ln less than ideal conditions, then the “fun” trying to get service and real suport started, a very unpleasant experience, so never again, factory new from now on.

      Ouch.

      I got a RAM exchange engine for my 210 when a spalled lifter took out the camshaft and was happy with the engine itself. However, I had a ton of problems with the various accessories that took most of 100 hours of flight time to finally sort out.

      Hard to justify a $60k new engine vs a $20k repair however. If I could guarantee that the new engine would run 1,600 hours without any problems I’d jump on it, but we all know that’s just not the case.

      Unfortunately, it’s a bit of a crap shoot no matter which direction you take.

      Touring the Continental factory a few months back was cool though – I was impressed with what they are doing.

      Robert

      #95734

      Yes, when it comes to piston engines it is a bit of a “Crap Shoot”, {As Sir Frank Whittle, the British jet engine pioneer said, “reciprocating motion is OK in human re -production, but not so good in propulsion”,} As for cost, our aircraft is a buisiness tool, with a bit of charity flying on the side {Cancer cases} so the cost is not so important as it would be to a private owner, however we dont want to go through the grief we had with the last re built engine if we can avoid it, also down time over a few days gives us a problem, our utilization is about 400 hours a year on average and our flights are time sensitive, the aircraft keeps us ahead of the competition, {who thankfully have yet to work out how we always seem to beat them to the next customer, I hope they never learn about “Flight Aware!} Keep us posted on how it goes and good luck!

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