i wanted to know what happens when one your plugs looks like its been hit or smashed on the threaded side im guessing the piston hit it but how

 

hum, ive seen this before but never really thought about it.

 

That's usually the case. Make sure its the right size plug, your engine is timed correctly, the proper sized head gasket is on there (i.e. not high compression, etc.), and that the head has not been milled past the acceptable limits.

 

HMM whats the possibility of someone over tighten em???

 

do you think it messed the motor up

 

broken sparkplugs are really bad.. i have seen them in a couple different scenarios... the first is the side electrode being melted off, which was from a boosted car running way too lean. the sparkplug otherwise looked ok, but was pretty white.
the other, i have seen the spark plug totally chewed up, and that was a piston that was destroyed to the point that a large peice of it smashed the end of the sparkplug. when i took the head off to do a post mortem, there was a hole in the piston. there was a hole in the side of the block though also.

dropping a valve also can cause you to smash a sparkplug, but i havent seen that one yet.

either way, i would do a compression test to see, because in most scenarios where a sparkplug gets mangled, you are looking at catastrophic failure