Would you overhaul?

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Racerx

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Ernie
Got an almost midtime io 540 in annual now. Good compressions. Good oil. Nothing in oil filter. But then they took the screen out and had an almost dime size chunk of aluminum off the accessory housing near the magneto gear boss I believe. Not sure how or why it happened, but it happened. Looking at the broken piece it appears to have had some slight discoloration like it was cracked for some time before letting loose, not like something else impacted it. They don't think they need to pull the motor to take the case out to get repaired, but they also said if an overhaul was a consideration now is the time. Why would it be a consideration since everything else is good?My attempts to post pics have failed miserably. Appreciate someone else's perspective!
 
I would like to know exactly where it came from, what that piece of metal was designed to do, and what caused it.
Large pieces of metal don't normally just fly off the inside of an engine.
 
Was there metal in the oil filter, oil pickup screen, or in the drained oil (drain it through a screen)?
 
My first thought is that Pop's wants to get Spridel and Chim-chim busy to pay for Speed and Trixie's wedding without selling the Mach 5.

But then... I'm not an A&P.

I'd ask if it effects being returned to service. If they do return it to service I'd treat it as an IRAN item. Really depends on your mission characteristics and risk aversion philosophy. Would this be your chosen overhaul shop if they had not discovered this?
 
Part came from I believe the suction screen. (Screen cames from pilots side fwiw) A/p said that's where larger pieces get caught before more damage. The oil itself and the oil filter looked good. Wouldn't be my first choice for an overhaul, shop more well known for that isn't too far away. He suggested pull the case off and send out for repair to Divco. I just worry about what else was floating around. I work with metal and have seen bad castings and that's what this looks like.
 
This sounds like a good candidate for IRAN with a reputable engine shop. Pending on what’s found maybe an overhaul is in order. If it were my aircraft I would like somebody with the repair station certificate perform the IRAN, But that’s just me as I’m overly cautious.
 
Not opposed to risk. On more than one occasion I raced someone else's car to shake it down for him and help him out. Nobody told the track announcer so that's where the name came from. But that's on the ground. In the air...way less risk averse. My A/P already talked to the Poplar Grove about the situation and with the rear housing having to come off I think the IRAN is probably the way to go and see what happens.
 
First thing I would want to know is how they made such a specific determination on the origin of the material without disassembly. My personal suspicion is that they’re shooting in the dark and don’t really know yet.

As far as my recommendation goes, based on the aforementioned suspicion, you need to find out where the part came from before you can decide how to proceed. Closing the engine back up and taking no action might be appropriate or if a discovery is made while the engine is open an overhaul might be the better choice. Nobody here can give you an answer without seeing what you’re working with.
 
I would not overhaul the engine based on this thread, that’s way beyond fixing nuances like this.
 
mondtster said:
First thing I would want to know is how they made such a specific determination on the origin of the material without disassembly. My personal suspicion is that they’re shooting in the dark and don’t really know yet.

As far as my recommendation goes, based on the aforementioned suspicion, you need to find out where the part came from before you can decide how to proceed. Closing the engine back up and taking no action might be appropriate or if a discovery is made while the engine is open an overhaul might be the better choice. Nobody here can give you an answer without seeing what you’re working with.
Click to expand...

Mags were pulled and could see from borescope. Just got to a pc this morning to resize the images. Still kind of tough to decipher.
 
unsafervguy said:
Looks like the casting where the gear shaft rides. My name would not go in the logbook without at least an Iran if the acc case.
Click to expand...

You are correct. Accessory case with the piece broken from a boss by the gear. As of right now the plan is to pull the accessory case and send it off for repair and machining at a certified shop. Just wonder why it broke and what much smaller particles came off with it. The oil and filter looked good so it's not making metal...
 
Yep, pull the accessory case and get it IRAN'd. BEWARE, it (nearly) always takes longer, and costs more than you expect. You never know what else is waiting to be found..
 
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