Looks like Babbitt.  I would expect you to find a main or cam bearing that is 110% toast.

I would tear the engine all the way down and inspect everything.  My thought is that it may not be metal, at least not in the conventional sense.  I'm wondering if this isn't the fallout from one of those head gasket sealer or other engine fix in a bottle treatment.  My thought was excessive silicone use, but obviously that's not what it is.  So then I thought about some kind of epoxy like JB Weld, etc. 

Not in the pan but imbedded on one of the pistons.
I had a Boonie Bug van with a Corvair engine that had  been on the road for a couple of years. One day while towing a camping trailer it developed a kind of a knock, more like a rap though.
The engine had never been opened and was still original. When I took the heads off there was a half inch long piece of piston ring pounded onto one of the pistons that hit the head on every up stroke.  On further disassembly every ring on every piston was still intact and where it came from is still a mystery.

Maybe they used lead to balance the crank, got hot and it melted.

Cab4word67 wrote:

Back in the sixties there was a product called MotorManic or something like that, It looks just like that in your pan. it was to make the motor stop smoking. I have found stuff, must be Ford gremlins in my pan that no one can explain also.

Years ago my son Had a Lincoln MK 7 with a 5.0L in it. He was driving down the freeway when the engine started making noises and his oil pressure went to zero. He pulled over and called me and we got it towed home. I pulled the engine and found a couple of small steel pellets in the pan, and one in the oil pump. It had seized and the driveshaft for the pump had twisted in half. I got a new pump, driveshaft and after looking at all the rod and main bearings, I replaced them all with stock sized bearings as there was no damage and minimal wear. Reinstalled it and it ran fine. I could not figure out where those three steel pellets had come from. I called a guy who ran a rebuild shop and asked him and he didn't know what they were either. However, a couple of weeks later, he called me and said he had figured it out. The pellets had come from some valve cover gaskets. The gaskets had the pellets embedded in them to keep the gaskets from being over tightened. He had another engine come in that had some in the pan. Someone in the past had replaced the gaskets and didn't notice the pellets falling into the head where they were eventually washed by oil flow into the pan. Strange things found in the pan for sure. 
 

Daze wrote:

Sadly you were correct

Bentworker wrote:

Looks like Babbitt. I would expect you to find a main or cam bearing that is 110% toast.

I pulled the main caps and the main bearings looked good all be it worn.  The cam bearings were a different story 3 out of 5 were completely shot and missing sections. However the cam looked good.  The middle section had some marking on it but nothing that I wasn't able to polish out.   Not sure why this engine was running "fine" and not making noise.  It confirms an "oil issue" that I knew about but thought I had avoided when the engine sounded good.  The previous owner (before he died) told me that after the truck was wrecked and brought to his house the oil lite came on.  He checked the oil and it was way low so he filled it up and fired up the truck.  The steering was messed up in the wreck making it almost undriveable (I think it was toed to his house) but he was able to drive it around to the back of his house where the oil light came on again.  When I pulled the motor I saw the oil filter was bent and not seated properly from the wreck and the reason for the oil problem.  After pulling the motor I put it on the run stand, changed the oil and crossed my fingers.  When it ran fine (I still can't believe it ran fine)  I figured it had not been without oil long enough to cause major issues.  Guess I was wrong.  looks like I need to fire up the lathe and make a cam bearing removal tool.
 

Be sure to check the oil pump, years ago when I wiped some main bearings on our drag car (289), some bearing material did make its way into the pump, but we did have oil pressure.
 

Rudi wrote:

I seriously doubt that the material is babbitt. The Babbitt layer on laminated layer insert bearings in a car engine are very thin and does not seem to be of sufficient quantity to what is in the oil pan.

Also, why wouldn't it be ground up to dust in the oil?  I don't see babbitt clumping together to form that. 
 

Seeing that kind of damage I would be taking everything to the machine shop to at least verify that nothing is out of whack.

TKOPerformance wrote:

Seeing that kind of damage I would be taking everything to the machine shop to at least verify that nothing is out of whack.

I agree, seems something seems out of whack, suggest checking the oil passages to the cam bearings.  Maybe the cam bearings weren't installed properly aligned to the oil passages? 
 

BobE wrote:

I agree, seems something seems out of whack, suggest checking the oil passages to the cam bearings.  Maybe the cam bearings weren't installed properly aligned to the oil passages? 
 

I think it was just a lack of oil and the result of the wreck.  The truck ran beautifully before the wreck and as I said before it was run with all the oil pumping out which would mean no pressure to the cam bearing but the crank and rod bearings would still see some from the pan.

Daze wrote:

 It confirms an "oil issue" that I knew about but thought I had avoided when the engine sounded good.  The previous owner (before he died) told me that after the truck was wrecked and brought to his house the oil light came on.  He checked the oil and it was way low so he filled it up and fired up the truck.  The steering was messed up in the wreck making it almost undriveable (I think it was toed to his house) but he was able to drive it around to the back of his house where the oil light came on again.  When I pulled the motor I saw the oil filter was bent and not seated properly from the wreck and the reason for the oil problem.  After pulling the motor I put it on the run stand, changed the oil and crossed my fingers.  When it ran fine (I still can't believe it ran fine)  I figured it had not been without oil long enough to cause major issues.  Guess I was wrong.  looks like I need to fire up the lathe and make a cam bearing removal tool.
 

The bearings were the OEM FoMoCo units, in fact I don't think anyone had been inside this motor since the original build.

 

I am thrilled this whole thing happened. What a fantastic learning experience. The engine was a spare and I never put it in a car so there was no lost time there.  Not only did I see somthing I had never seen before but I also learned several ways to change cam bearings with out farming it out to the shop.  It's just one more thing I can add to my knowledge base.

The ever inquisitive and talented Daze...strikes again!
How bout machine the block to take some one off roller bearing cam bearings!
If anyone could do it......
6sal6