Just replaced rod bearings and car drove fine went to start her up and bam a nasty sound ... so I cheaked the spark plug and it was smashed no misfire or anything just a knock noise and smashed splug looked in at the piston and no damage what could it b??? N e help would appreciated thanx

 

drop your pan see if your rod came un bolted

 

The spark plugs I bought from auto zone were longer then my previous ones ...how do I go about taking off the head and knowing that the piston or rods are screwed just did the rod bearing and everything was intact.I have a b18a1 93 ls1.8 non vtec swap into a 90 si hatch ...