This is a comprehensive reference book for diesel engines with a 4 1/2" bore and 4-cylinder configuration, specifically designed for Caterpillar equipment. It provides detailed information on the D315, D4, NO 112, and NO 955 models, making it an essential resource for anyone operating or maintaining these engines. The book was manufactured in the United States and is branded by CAT, a trusted name in heavy machinery. Whether you're a professional mechanic or a DIY enthusiast, this reference book will provide valuable insight into the workings of these powerful engines.