[Al Skierkiewicz]

Let us not forget the Mitsubishi engines that were used in Dodge minivans for a while. In an attempt to make a light, powerful, V6 in a small package, something had to give. The designers left out a main bearing that provided stability to the crankshaft. As the engine aged, the crank would wobble back and forth until it finally wore itself through one end of the engine. I know of several owners who lost one of those engines. One on the first leg of a three week driving vacation with the family. How do you recover from that? No car, no vacation and far from home.
Errors creep in to designs everywhere including Detroit and Japan.
Racing engines add more bearings than normal "street" vehicles and balance like crazy to minimize vibration so that RPMs can be maximized. I'll let someone who knows chime in here, but I believe a Formula 1 Ford engine tops out over 10,000 RPM without shaking itself apart, while street vehicles are designed to run at less than half that.