When I was talking to my buddy's dad who runs the top fuel Harley's, he say quite a few guys have been killed on them from the heads flying up and hitting them in the chest causing irregular heart beats and eventually heart attacks. Sometimes the force kills them on the spot. It really is a very dangerous fuel/machine/sport. I know he wears a hard chest protector and has straps over the motor, but there isn't really a good way to make it "blow up safely". His bike is capable of 800 HP (that is what I have been told) and that sounds like a lot, but most people don't even realize how much that actually is.
One person MIGHT be able to produce 1 HP with all his muscles working at once (for a very short amount of time). No imagine 800 people working together for one burst and put that burst into the form of an aluminum motorcycle head flying toward your chest! I think engines are amazing, the amount of abuse they can take, the forces they can withstand, and the fun they can produce!