Very odd, completely confusing

[SlidewaysScott]

Real quick story into this. I had my engine ready to go and had it running many times. Finally get it to where i can test drive it for the first time, started it up....and started hearing a banging noise, not like a rod bearing or consistent like one and really random, we really didn't know what, but it was in the bottom end.

I did a compression test cyl. 1 - 3 were 151, cyl 4 was 80...and also noticed that the spark plug was bent.

Figuring I have a f'd cylinder or bent valves, we tried a leakdown test next.

Heard air coming from the exhaust on all cylinders and from the valve cover on cyl 4. So by now I'm just like GREAT, bent valves for sure We go ahead and pull the head off... and we see this on the piston:



i cant even explain what it is. it looks like solder that fell in there or something and was getting smashed up...cause its not from anything on the head or the piston. ANY CLUE WHAT THIS CAN BE...OR WHAT FROM???

also just some more confusing info, the cylinder walls....completley fine, no gouges, scratches, etc. just smooth and you can still see hone marks...