Been awhile for this thread but went back and read my Dec 29th post and........Sure glad you figured it out and let us know.

180Marty wrote:Been awhile for this thread but went back and read my Dec 29th post and........Sure glad you figured it out and let us know.

Yeah you definitely called that! The engine shop I’m planning on using said it’s not a common occurrence. Have you had it happen before? $20 in parts leading to a engine failure..

NWestern180driver wrote:

180Marty wrote:Been awhile for this thread but went back and read my Dec 29th post and........Sure glad you figured it out and let us know.

Yeah you definitely called that! The engine shop I’m planning on using said it’s not a common occurrence. Have you had it happen before? $20 in parts leading to a engine failure..

It's happened on 2 engines I know of in the last year. Both about 600hrs on them. They weren't as lucky as you and had major failures in flight. Thank fully no injuries. Rebuild sheets didn't show new retaining clips. Builder got POed and sent lawyers after the shop that dissected the engines rather then figuring out if they actually had an issue or not... I will no longer recommend those engines.

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Never heard of it before but from the symptoms you described it seemed like a possibility. I think I read that at overhaul the first thing you do is remove and discard those snap rings on the counterweights never to be used again. Will the crank be able to be used again assuming it was good otherwise?

180Marty wrote:..... I think I read that at overhaul the first thing you do is remove and discard those snap rings on the counterweights....

I just read through the 470 overhaul manual I have on pdf here on my laptop--
nothing about discarding those snaprings or about installing new ones.
But considering the minor cost of doing so,
it sure wouldn't be a bad idea, if just for your peace of mind.

180Marty wrote:Never heard of it before but from the symptoms you described it seemed like a possibility. I think I read that at overhaul the first thing you do is remove and discard those snap rings on the counterweights never to be used again. Will the crank be able to be used again assuming it was good otherwise?

Well nothing is official yet, but from what my mechanic saw just inspecting from a flashlight after dropping the oil pan he said it looked good all things considering. So I hope it’s will be salvageable. Won’t know for sure till the engine shop tears it down completely and inspects. With that being said, this engine only had about 500hr SMOH, but I guess that was a “Feild overhaul”. It was OH in 2000, and I put 420 hours on her in the last 5 years. Happy for sure this happened on the ground as I do fly my family in the plan often. I think if anything after I get a new engine on I’ll be doing a lot more engine out practicing. Definitely has been a heck of a learning experience that’s for sure. And a expensive one. But the bird is part of the puzzle where I live and what I do so she will fly again, probably sooner than later, builder is saying June for the Ponk conversion. So I won’t entirely loose my season for peace destruction!!!!

J-

Sure does give one something to think about flying over cold water, have altitude!

Glad it worked out safety wise, the $ sure is a bummer though. Thanks for keeping us posted and updated, I’m sure someone here will benefit from your experience.

Kurt

I just read through the 470 overhaul manual I have on pdf here on my laptop--
nothing about discarding those snaprings or about installing new ones.

I just got back home to my computer and found a screen capture I saved when we were talking about "orders" of counterweights..

Good catch Marty.
What publication is that table out of --
an overhaul manual revision, service bulletin, or ??
My 470 OH manual is an old edition,
I just have it for reference.
Any actual overhauling or major wrenching would require a newer, up to date version

Not sure if I can find it again on internet but looks official. Something else I thought about is what if there is a flake or debris n the groove the snap ring fits in so it can't totally get seated properly.

That table is from Continental’s Standard Practices manual, M-0.

It’s a free download from their website.

Chris


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