This workshop service repair manual provides comprehensive information for the Volvo B21 Engine. The B21 is an inline 4-cylinder, water-cooled engine with a displacement of 2.1 liters, featuring a cast iron block and aluminum alloy cylinder head. Depending on the specific variant, it utilizes either carbureted or fuel injection fuel systems and a distributor-based ignition system. This engine, known for its robust construction and reliable performance, is applicable to various Volvo models across different production years. This manual is designed to assist owners, mechanics, and technicians in understanding, maintaining, and repairing the Volvo B21 Engine. It covers essential procedures, including detailed specifications for engine components, maintenance schedules, and troubleshooting guidance. Topics addressed include lubrication requirements, ignition timing adjustments, spark plug specifications, valve lash settings, and timing belt replacement intervals. The English-language manual offers in-depth technical data to ensure optimal engine operation and longevity.