Inspection of Crankshaft I.D. for Corrosion on Lycoming Engine SB 505

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acena
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Inspection of Crankshaft I.D. for Corrosion on Lycoming Engine SB 505

During an Lycoming O-320 E2A engine overhaul, the internal diameter of the crankshaft was found with corrosion and shop engine removed corrosion but the final diameter was over the max permitted limit per SB 505 (1,920 instead of 1,910).
this shop engine decided to re-install this oversize crankshaft as per an approval repair procedure allowing the I.D.of the crankshaft to be machined up to 1.920. after several request for a copy, it is not possible to know exacly if this approval process exist and who approuved it.
Question: somebody know if this process exist in other engine shop and if is it an Lycoming approval procedure ?

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bob.pasch
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Personally, I don't know the answer to your question but when I have a question about engines, I call Jeff Tyler at Penn Yan Aero Services. Jeff is extremely knowledgeable when it comes to anything engines and if he doesn't know the answer his Chief Inspector Tim Hanson does! Give them a call at 800-727-7230. I'm sure you'll get your answer...

Dave (not verified)
Anonymous's picture

Years ago I had the same thing. I had one that measured .010 over on the ID. The last overhaul was done by Penn Yan. As I recall from my conversation with them they have approval to do this.

bob.pasch
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That wouldn't surprise me, they have a slew of mods and STCs...

brett C (not verified)
Anonymous's picture

I know of two companies in Australia; one the has approval to take the I.D out to 1.930" and the other shop 1.940" so I wouldn't be too concerned about it at 1.920"
Cheers

acena
acena's picture

Hello evrybody and thanks a lot for your answers.
In the same time and for your information, i asked to LYCOMING if they know a approval procedure to oversize this limit and find below the answer:
"Lycoming has no approved data that will allow the internal diameter of this crankshaft to exceed 1.910 inches."
Now if someone has an STC or another approval document. i'm looking for that
My Email adress is [email protected]
have an nice day

bob.pasch
bob.pasch's picture

HELLLLOOOOOO! Did you read the previous posts Acena? What did you expect Lycoming to say? No manufacturer, Lycoming included, will give you ANY information for changing, modifying, altering or adapting any product that they produce! It's not in their best interest and opens a liability issue.

There are two posts who told you to call Penn Yan and one said to inquire in Australia. Try them FIRST before you ask the same question again! I really enjoy helping others when I know an answer [and I'm sure the other posters do as well] but it really is annoying when you get the answer, you ignore several answers and you ask the same question again. You have two places to start! The professional thing to do is to help yourself before you ask us for help again...

JohnDC3 (not verified)
Anonymous's picture

Dude, Just bite the bullet and get a new crankshaft. Just because Penn Yan says it can be done and they have an approval, doesn't make it right. I for one would not buy a plane knowing that this had been done just because you want to save some $. the folks at Lycoming have been building engines for years, I think they know what they are talking about, and don't bring the Liability card to the table cause every mechanic and IA out there asumes liabilty every time they put there name in the logs.

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