Assuming no design flaws or problems arising from the cheaper parts favored by financial officers, and that the engine is properly tuned, as in previous article, and the oil changed frequently, a production engine can go 200,000 kilometer or more before it wears out. This being the case, is custom balancing and blueprinting really worth it?
Sure it is, and here's why: First, understand that those 'last forever' production engines you read about are the exception rather than the rule. Bucking the law of averages, the parts that went into them just happened to have ideal clearances when the engine was assembled. The slightly undersized shaft "just happened" to be installed in a slightly over-sized bearing, and the engine was custom-blueprinted by coincidence. You don't hear much about the engine that wore out prematurely because an undersized shaft was mated with an undersized bearing, or the one with the over-sized shaft that was stuffed into an over-sized bearing.
Comparing to the components in a haphazardly assembled production engine, those in one that has been carefully balanced and blueprinted will operate with less friction and less vibration. The engine will be smoother, quieter, more powerful, more economical to operate because of decreased gas and oil consumption, and it will last longer.
Conclusion, in closing, I must mention that many factors outside the engine can cause vibration and poor performance, so be sure to rule them out before going to the expense of having your engine removed for balancing and blueprinting.