I don't see how over torque would break the insulator. No pressure is applied to the ceramic unless something else is done wrong. Are these a two-part plug where the ceramic is the only connection between the hex and the threads of the plug? In the old days with steel and cast iron and even beefy aluminum heads the the torque wasn't a big deal - just make it tight. Today's engines are a different story. I cannot remember the last time I saw a steel head. The aluminum heads are much thinner to save weight and cost and that means fewer threads engaged with the plug. The problem I see with over torque is stripping the threads in the head. Some people under torque. The spark plug ends up loose and can even blow out, perhaps taking the head threads with it when the manufacturer took the thin head too far (Ford 4.6L v8 👀).
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
Can write it bigger
I don't see how over torque would break the insulator. No pressure is applied to the ceramic unless something else is done wrong. Are these a two-part plug where the ceramic is the only connection between the hex and the threads of the plug?
In the old days with steel and cast iron and even beefy aluminum heads the the torque wasn't a big deal - just make it tight. Today's engines are a different story. I cannot remember the last time I saw a steel head. The aluminum heads are much thinner to save weight and cost and that means fewer threads engaged with the plug. The problem I see with over torque is stripping the threads in the head. Some people under torque. The spark plug ends up loose and can even blow out, perhaps taking the head threads with it when the manufacturer took the thin head too far (Ford 4.6L v8 👀).