First published an incredible 25 years ago and regularly reprinted ever since, this remains one of the most comprehensive references available to the enthusiast engine tuner and race engine builder. Drawing on the author's many years of practical experience in tuning and modifying high-performance road, rally and race units, every aspect of an engine's operation is explained and analysed. Detailed modifications and improvements are suggested and described in the author's practical, down-to-earth style, making this book essential reading for anyone involved in building high-performance engines.