new engine making metal

[robbie]

A friend just completed a complete rebuilt of his C-90 for is Cub.
Case was line bored, accessory case bushed and cleaned up. Cly's. bored to .015 over,and a new cam.
After about 1 hour of flight, we pulled the oil filter, not the screen, he's added a filter. There is a lot of aluminum in the filter.
We think it's coming from the wrist pins end covers.
Any one out there gots any ideas or suggestions??

[Ray36048]

Re: new engine making metal

My friend had the same results with his overhaul. It made metal for about 25 hours. The engine shop told him not to worry unless it was making metal after 25 hours. But, I would keep a close eye on it.

[alwaysoar]

Re: new engine making metal

This is not likely on a new engine, but are you sure that what you find in the filter is not carbon? Carbon is flakey, and looks like metal, but it falls apart easily if you rub it between your fingers.

[robbie]

Re: new engine making metal

The specks are shinny, we chaged the filter and flew it another hour tonight.
Better results, only saw two specks of silver stuff.
Will change the filter again and fly tomorrow, will let you know the results.

[crispy critter]

Re: new engine making metal

Robbie,
It is not at all uncommon on a fresh overhaul to find aluminum in the screen or filter especially in the first 5 hours or so.It is very common to get shavings or aluminum dust from the rings as they seat themselves in.If you were getting steel shavings or steel particals then you might want to worry a little bit but I would give it 10 to 20 hours before I started to worry about it unless the shavings start to turn into chunks.

[AndyDuke]

Re: new engine making metal

Robbie,

I had an overhauled engine fitted to my Taylorcraft 2 years ago. I glued a small magnet into the sump plug to collect any metal deposits floating around in the sump. After the first oil change done during the first 5 hours of flight, the magnet was covered with minute particles which felt like a thick paste. This can be expected as the rings bed in and grind away the surface of the honed bores. There were no large particles on the screen. After the first 10 hours of running in, the amount of deposits on the magnet reduced to almost nothing.

As long as you don't see any large bits of metal, I think you are just experiencing the normal running in effects.

[flyguy]

Re: new engine making metal

Just a thought: If you kept the aluminum bits you might get someone to look at them under a microscope. Their shape would might give you a clue as to where they are coming from. For example are they chips or thin "shavings."
I also suspect that it is not unknown for metal from the machining process to be hidden in some crack or cranny somewhere and not come out until you run the engine.
Darryl