Spark plug smashed no rod knock

[cvfitzwater]

So my deal is a couple days go I was driving my 240sx with a ka24de it started running like crap almost like a clogged cat but with my luck it wasn't I pulled the spark plugs and number 3 cyclinder had been completely smashed but looking into the spark plug hole there's no visible damage to the piston then I pulled number 3 the gap was closed on it the first picture shown is #3 and the second is #4

[kruked]

No picture(s) posted.

Step #1
Post picture(s).

Step #2
Throw some punctuation marks in your sentence.

Did you put some new(er) plugs in the 2 cylinders and see what happens just for shits and giggles?