Although short, this article aims to clear up some of the apparent confusion regarding so called “blueprinted” engines.
There is a misconception amongst racers and sadly some buyers that a so called “blueprinted” engine is a tuned engine. This is not the case, a blueprinted engine is an engine that has been measured and adjusted/modified so that it meets exactly the dimensions and tolerances that the designer of the engine specified. There are very few, if any, of these engines in circulation, as the manufacturer is most unlikely to allow anyone access to the data from their drawings.
If you were to be able to buy a blueprinted engine it would offer negligible performance gains due to the accuracy and consistency of modern production methods. It would however run more smoothly and efficiently. Because of the closer tolerances it would take longer to “break in” but, with proper maintenance, would last longer. The person who would gain the most advantage from such an engine would be the engine tuner, who would have an accurate baseline upon which to calculate his/her modifications.
As mentioned above, some buyers are given the impression that they have purchased a “blueprinted” engine. Whilst the seller could try to justify that the engine is made from blueprints of the original drawings, and therefore it is a blueprinted engine, it is a deplorable and unforgivable way of making a sale. The customer usually pays an extra amount for this “high performance” engine only to find out later that it is a standard “off the shelf” engine.
This practice by, thankfully, a minority of unscrupulous dealers will continue as long as there are customers who do not do their homework and impulse buy an engine that they are lead to believe is faster or better than it actually is.
Many thanks to Rob Lochier of Alro Racing Systems for his assistance in the preparation of this article.