1. What could blow the head of the spark plug in a stock car?
2. What is the correct way of fixing the car when you notice the blown spark plug and coil pack?
3. Is the initial blowing of a spark plug what causes catastrophic engine failure, or is the engine save-able if it was repaired correctly? (removing the old plug and the broken pieces, and installing a new one)
4. Do bad spark plugs blow up coil packs, or do coil packs blow up spark plugs? I'd love a detailed response to this...

Thank you.

 

You probably need to ask this question to the spark plug company that made your plugs. They would know more about their product than we would.

 

in some instances detonation can blow off plug electrodes, in rare instances it could be a defective plug but not often. A lot of s2k guys have been getting loose spark plugs which back out of the head and cause damage that way, which often takes the coil with it and introduces how air, gas, and oil up into the coil and spark plug well. This is the most likely cause of your situation as detonation is usually rare on a naturally aspirated setup.

If the plugs were quite old the electrodes can wear down slowly , eroding over time until there is nothing left of the ground electrode and the center electrode wears down as well. This is the safest condition but it doesn't usually take a coil with it.

In the case of electrodes breaking off it's all the luck of the draw, in many instances they blow out the exhaust and it's possilble not to have engine damage, if they roll around in the cylinder for a bit they could score the cylinder wall. It all depends on how much of the plug broke away, just the electrodes or part of the plug body too ?

It may help diagnose the issue if you had some pics of the damaged plug and coil ?