Ring Failure, what am I missing?

[divingmikeboats]

Brand new owner of 1969 Series with 2.25 petrol. Unknown miles on it. A loud engine knock brought the price into range so what do you do? Anyway I pulled the head and found severe damage to #2 piston head and less so to #1. Iron bits hammered into the aluminum. See pics. I pulled #2 and found the rings had come apart causing the piston damage. I figured to find the same on #1 but when I looked at it the rings were fine, gaps in range and no other issues I could see. I'm normally a bit slow but how did the bits from the rings on #2 do damage to #1? Would you all replace both just in case or is there some other explanation. Bottom end rod bearings all gaged out OK by the way.
The head has little to no damage from the rings. Smooth with a few scratches. Cylinder walls are also undamaged. Any ideas?

[o2batsea]

How do you know that the ring failure on #2 was the cause of the damage on #1, are you just assuming that it was or do you know for a fact that the metal pieces in #1 are indeed bits of ring from #2?
I suppose that when the intake valve comes open the ring bits have an escape route up and out, and the airflow of the manifold would naturally direct them to #1, but there's no way to actually prove it.

[divingmikeboats]

Metal bits hammered into top of #1- just guessing they came from #2 because the rings on piston #1 are still in prime shape. The pattern of the damage and remaining pieces on #1 are identical to those on #2. There were no loose metal bits in the oil pan either. No issues with the valves.

Hard to picture metal bits moving against the intake flow but I see no other means. I guess I could be looking at older damage.

[divingmikeboats]

To finish up- I replaced only the piston with the broken rings. Runs like a scalded cat, well a three legged one.

[CKubinec]

I'm amazed that the cylinder wall isn't scored with that much piston/ring damage. On our racing engines it wasn't unusual for chunks of valves or pistons to pass from one cylinder to another when they let go. Of course those were turning a lot higher revs then a LR engine. If it were me I would replace both pistons. The top of #1 piston could now be cracked and you wouldn't even see it. Good luck.

Didn't see that you had it back together. Hope it stays that way!!