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Cracked case -- totally bummed -- question?

db8

Well Known Member
Have always noticed a very slight bit of oil near the #2 cylinder on the cowl since the beginning. I have a little over 100 hrs on the plane and engine (mostly new parts except yellow tagged crank case and cam).

Noticed a little more oil on the bottom lip of the cowl after a flight on Weds. Thought I'd check everything out before the trip to Oshkosh. When I took the cowls off, noticed more on that left side of the inside cowl than normal. Didn't take long to find the thin crack at the cylinder bolt. I wiped it off, did an engine run, and it is weeping from the crack. I can run my finger across it and the nail catches (it's not a paint crack). I think I jinxed myself because after the flight on Weds, I told my hangar mate it sure is nice having a plane that just runs great. I am totally bummed about not flying to Oshkosh and having to swap out the case.

I have decided to buy a new Superior case (am going to do this Monday). I have their crankshaft and cold air sump and am real happy with what I have. They are always great when I chat with them on the phone. My question is: Since I am swapping out the case, should I pay the extra money (not sure, but thinking about $1500 or so) and go with the roller lifter technology? I have heard pros and cons about both. As of now, I plan on converting to the roller lifters from what I have researched. Any thoughts, especially from those who have had both and are experienced in this area? Thanks. Dave
 
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Cracked case

When I sent my case in to Divco to be checked and
tagged. The guy I spoke with told me that 90% of the cases
that get sent in, have small cracks that need to be repaired in the same area
you mentioned. Leeds me to wonder if that one was missed or the crack
redeveloped?
 
Can the case be welded.. Not wishing to challenge your decision but Divco will crack test the whole thing as repair as needed for presumably a lot less $$$

Frank
 
I'm no engine guru, but would you really lose enough oil on a trip from IN to Oshkosh from a crack to cancel your trip? I don't like oil leaks at all, but most engines leak a little anyway (not mine, of course).

Couldn't you fix it after Oshkosh?

Just curious.
 
I'm no engine guru, but would you really lose enough oil on a trip from IN to Oshkosh from a crack to cancel your trip? I don't like oil leaks at all, but most engines leak a little anyway (not mine, of course).

Couldn't you fix it after Oshkosh?

Just curious.
A crack in the case is difinitely a no fly situation. Catastrophic failure can happen at any time. Losing oil is trivial when large chunks of the engine casing is leaving the aircraft. A crack is an anomaly that can't be fully quantified visually without further inspection with special equipment. Please don't take discrepancies like this lightly.
 
There should be a chamfer where the studs are threaded in the case. If not...then I would have a serious talk with the shop that did the case.
 
I agree about the no fly. The crack has definitely gotten worse, because there is more oil and it has become visible for the first time. It's about 2 1/2" inches right now. Believe me, I thought about going anyway (with the airplane) for a nano second, but then decided it's not worth the chance. I plan on going to OSH for a couple of days, just without the plane.

The company is out of business that did the overhaul. I don't remember their name (form in the hangar), but the form 8130 showed them out of Tulsa and the name started with a C and the second word was started with an S. Divco were the ones that told me they are no longer in business.

Does anybody know if there is a new flyoff requirement? I have heard 0, 5 and 40 hrs as possibilities? I guess I have to let the insurance and FSDO know of the new serial number on the engine. Then the FSDO will let me know the limitations from what I understand.

Planning on going with the roller lifters and making the order tomorrow. Thanks. Dave
 
A crack in the case is difinitely a no fly situation. Catastrophic failure can happen at any time. Losing oil is trivial when large chunks of the engine casing is leaving the aircraft. A crack is an anomaly that can't be fully quantified visually without further inspection with special equipment. Please don't take discrepancies like this lightly.

I wasn't taking anything lightly. I was just asking because I don't know squat about engines. Now I know.

I suppose that means that stop-drilling the crack is out of the question? :D
 
roller lifters

You should ask some more questions from Superior on their new roller lifters. From what I hear they are not the same as the Lycoming's and they are a new design from their original.

Jesse
 
Case

I use Chuck Ney in Tulsa. Probably a quicker turn around than Divco. He also has a lube STC you may want to add.
 
I wasn't taking anything lightly. I was just asking because I don't know squat about engines. Now I know.

I suppose that means that stop-drilling the crack is out of the question? :D

I'm not an engine guy but my understanding is that there are "acceptable" case cracks according to the manufacturers. Google "acceptable lycoming cracks" and read to your hearts delight. I was going to buy a plane with a cracked case many years back and was concerned about flying it home. When I arrived to look at the plane it was in the pattern. I'm not recommending flying the plane in question, just passing on what I have read and experienced.
 
The problem I have with this case is I'm guessing it is run out. It has all kinds of stamped numbers on it, which means it has been overhauled a bunch.

I couldn't see the crack before (even though there was a slight leak) and now I can. It is getting worse. So without a question, I don't want to fly it this way.
 
I'm not an engine guy but my understanding is that there are "acceptable" case cracks according to the manufacturers. Google "acceptable lycoming cracks" and read to your hearts delight. I was going to buy a plane with a cracked case many years back and was concerned about flying it home. When I arrived to look at the plane it was in the pattern. I'm not recommending flying the plane in question, just passing on what I have read and experienced.

You read incorrectly as it applies to his situation.......
I'm surprised we haven't heard the JB Weld solution yet!
 
You read incorrectly as it applies to his situation.......
I'm surprised we haven't heard the JB Weld solution yet!

I didn't suggest this situation was an acceptable crack. I was just making a general comment that the some case cracks have been considered acceptable by the manufacturer. I was referring to some of the Continental engines, in particular the light case 520's.

http://www.bowersflybaby.com/tech/SB M90-17-Crankcase_Cracks.pdf

Edit: I do see that I referenced "acceptable Lycoming cracks" in my original post. I didn't do a very good job of making my point. As stated, I was thinking of the Continental service bulletin.
 
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JB weld won't work. You to have pop-rivet a proseal patch over it.

Proseal will not withstand the heat, you will need to use RTV if you want a long lasting solution.

Use pink RTV if you want ladies to fancy your engine.
 
My neighbor had a crack in his Bonanza's IO-470 case where the oil cooler mounts. He asked if it could be fixed with JBWeld. Ummm, no, sorry. :)
 
DIkking around aside, Robert is right though. Continental does allow cracks on certain cases in certain places.
 
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