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  #1  
Old 06-28-2022, 09:05 PM
mechmike mechmike is offline
 
Join Date: Feb 2020
Location: Powell River
Posts: 22
Default Certified engine <30 hours run time making metal

Not in an RV. This is my new engine in a certified C2 Skimmer (Lake amphibian pusher) that was making some aluminum.
Was making some aluminum starting at first oil change at 2 hours, then at 4, then 6 then 15 and at about 28hrs enough was enough and pulled the engine.

This is a freshly rebuilt certified case (and rebuilt engine). Just sorting out what on earth to do now.

For your viewing pleasure, hopefully this works out well and we can all learn from it:

https://youtu.be/JIP8Lh8EjdY

Mike

Last edited by mechmike : 06-28-2022 at 10:39 PM.
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  #2  
Old 06-29-2022, 12:34 AM
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rv8ch rv8ch is offline
 
Join Date: Feb 2005
Location: LSGY
Posts: 5,005
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That looks horrible. Were some critical components missing to allow the crankshaft to rub against the crankcase? Seems like whoever put that engine together has some explaining to do.
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  #3  
Old 06-29-2022, 08:18 AM
lr172 lr172 is offline
 
Join Date: Oct 2013
Location: Schaumburg, IL
Posts: 7,697
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I would not immediately jump to that area as the source of metal. The fwd face of the #1 journal rides against the case and acts as a thrust surface in tractor configurations. It would be really odd for a case overhauler to mess that up. In a pusher config, all the force is aft and the oil slinger hits the case in it's cavity and acts as the thrust bearing. Can't see that area with the case halves together.

Just because you see shinny AL doesn't mean it is wearing there. The case overhauler would have dressed this area as part of the machining process and not surprising that they ate into a bit of new casting area on the outside. That face of the case will wear, as IT is the thrust bearing. The case shop has to machine it back to flat and that means taking away some material. If it meets axial play spec, all good. If not, they weld on new material an machine again. In your case, it looks like they just machined it down and have to assume it still meets the thrust play tolerance. Just stick a feeler gauge in there to confirm.

Several areas of the engine can make AL shavings. I would keep looking. Does it have AL pin plugs? Those would be my first look. I had one that made metal for 100 hours after overhaul until l pulled them out. Wear on the plugs was less than I expected for the amount of metal found. The silicon bronze caps that make shavings can also be confused for alum, as they are still shinny and non-magnetic. Size is so small that you can't really see the unique color of bronze.

Larry
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Last edited by lr172 : 06-29-2022 at 08:33 AM.
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  #4  
Old 06-29-2022, 08:34 AM
lr172 lr172 is offline
 
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Quote:
Originally Posted by rv8ch View Post
That looks horrible. Were some critical components missing to allow the crankshaft to rub against the crankcase? Seems like whoever put that engine together has some explaining to do.
The crank is supposed to rub against the case in that area. It is what prevents the crankshaft from pulling out of the case. Every engine has thrust surfaces to deal with axial movement of the crank. Most use thrust bearings, but the lyc just rubs the crank against the case.

Larry
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Last edited by lr172 : 06-29-2022 at 08:45 AM.
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  #5  
Old 06-29-2022, 09:09 AM
664781 664781 is offline
 
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Location: Powder Springs, Ga
Posts: 360
Default Oil Pump

Disassemble the oil pump and see what it looks like. Just another source for metal.
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  #6  
Old 06-29-2022, 09:10 AM
mechmike mechmike is offline
 
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Location: Powell River
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Quote:
Originally Posted by lr172 View Post
.... Does it have AL pin plugs? Those would be my first look. ....
Larry
I have the cylinders are off to hopefully have found a pin plug shaved down. They were all good.

That I'm looking at here is it looks like the crank is wearing into one side of the case and the other side has a space.

Crank end play is ~.017 so within the huge spec they give.

More inside photos coming

Mike

Last edited by mechmike : 06-29-2022 at 09:15 AM.
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  #7  
Old 06-29-2022, 09:14 AM
lr172 lr172 is offline
 
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Quote:
Originally Posted by mechmike View Post

That I'm looking at here is it looks like the crank is wearing into one side of the case and the other side has a space.

Mike
Yes, the fwd end of the crank is rubbing against the case. This is normal and the engineered behavior. The question then is it just rubbing or making metal. Without a microscope, they can look the same. Remember, this area is flooded with oil from the main journal. What leads you to believe those two rubbing surfaces are making metal? Your engine has numerous metal on metal rubbing surfaces that aren't throwing metal.
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Last edited by lr172 : 06-29-2022 at 09:18 AM.
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  #8  
Old 06-29-2022, 09:16 AM
mechmike mechmike is offline
 
Join Date: Feb 2020
Location: Powell River
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Quote:
Originally Posted by lr172 View Post
Yes, the fwd end of the crank is rubbing against the case. This is normal and the engineered behavior. The question then is it rubbing or making metal. Without a microscope, they can look the same. What leads you to believe those two rubbing surfaces are making metal?
I can see a curl of aluminum that isn't visible in the video

Mike
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  #9  
Old 06-29-2022, 09:16 AM
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BillL BillL is offline
 
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Location: Central IL
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Quote:
Originally Posted by mechmike View Post
Not in an RV. This is my new engine in a certified C2 Skimmer (Lake amphibian pusher) that was making some aluminum.
Was making some aluminum starting at first oil change at 2 hours, then at 4, then 6 then 15 and at about 28hrs enough was enough and pulled the engine.

This is a freshly rebuilt certified case (and rebuilt engine). Just sorting out what on earth to do now.

For your viewing pleasure, hopefully this works out well and we can all learn from it:

https://youtu.be/JIP8Lh8EjdY

Mike
Mike, please post when you get the case split, it is not clear what has happened. We can see the curled aluminum, but is the thrust face recessed?

Thanks for posting - - hope you get satisfaction on this.
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  #10  
Old 06-29-2022, 09:21 AM
lr172 lr172 is offline
 
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Location: Schaumburg, IL
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Quote:
Originally Posted by mechmike View Post
I can see a curl of aluminum that isn't visible in the video

Mike
If the shavings are curled, that means large pieces. Split the case and look at the thrust surface. If it is making curled shavings any wear should be visible to the naked eye. You also need to examine the thrust surface in the oil slinger recess, as this will take the most abuse in a pusher config. In a pusher, the thrust contact at the #1 journal should be minimal.
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Last edited by lr172 : 06-29-2022 at 09:26 AM.
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