Here's a great example of what could probably be referred to as "Catastrophic Engine Failure." While my friend was driving his 1960s Buick down a Washington freeway, doing about 60-70, he noticed something strange. The 340 that powered his lead sled was suddenly not running. Of course this was not the only thing wrong with it, as the engine had quite effectively exploded.

Now the engine was not in the greatest of conditions, probably in need of a port polishing, new piston rings, sparkplugs, and other general maintenance. Whether or not it was any of this, or someone dropping any sort of additive into his fuel tank, we will never know.

What is important is the aftermath. Nothing was good on the engine anymore. Exhaust manifold, cylinder heads, intake manifold, all fried. What he did discover when he took it to the junkyard was that there were three IHOPpancake sized holes in his engine block. Needless to say, the car was considered totaled, and now rests in the form of a 4'x4' paperweight.