Real risk of head damage when changing spark plugs

[SteveSRT8]

The spark plug projects into the chamber on a lot of motors. I'm not sure on exactly how many, but it can't be too uncommon for the threads to see a bit of combustion!

The Ford issue is strange, ranging from truck engines into high performance cars, and I think it is a bit "amplified" by the internet.

 

[steve20]

To my 12 year old changing the oil: tighten the plug till it feels hand tight, turn it with the wrench till it first fells tight--closing remark: "It's (the drain plug) not holding up the George Washington Bridge,you know"