With the introduction of the Twin-Cam engine, Tim Remus saw the need for a book addressing hop-up and repair procedures for both the new engine and the older Evolution motor. His new book covers both factory and aftermarket engines and hop-up options. The development histories of the two engines are included, as well as discussions concerning how to approach modifications. Of course, the book also includes step-by-step instructions for various installation, repair, and modification tasks. A great selection for any V-Twin fan!