Healthy engine, mysterious metals

[no jared]

I was attacking a leak from my oil pan gasket after rebuilding my engine 1 1/2 times when I fished around in the oil pan and found chunks of metal(aluminum I suppose, it's definitely not iron) in the oil, I inspected the valve train and the crank and all the pistons and rods and I couldn't find a source of the break. I looked at every point on the cast of the head, and around where that contacts the cam and couldn't find a break. The head I have is a second replacement one. The casting texture doesn't match anything I've seen on the car and it looks like it had a circular hole carefully machined out of it. I only have a geometric arch of that hole of course. The engine is strong and doesn't tick or bang and runs well. Any thoughts?
Post MergeI will post a picture of the piece later I'm off to a party

[weitrhino]

Just about the only thing made of aluminum subject to oil circulation is the head. Rocker shaft bolts will too easily strip the aluminum threads out of the head. Eventually that will cause a rocker shaft to work free and snap in half. Helicoils will do a good job of restoring the stripped out holes but you cannot drill them out properly without removing the head first.

Having had this happen to me twice, I'd look there first.

[no jared]

Thanks I'll check it out