This workshop service manual covers Volvo engines from the B17, B19, B21, and B23 families, representing the early Volvo Redblock engine generation. These inline-4 cylinder engines, known for their robust cast iron block and aluminum cylinder head construction, were available in displacements ranging from 1.7 to 2.3 liters. They feature an overhead camshaft (OHC) design and utilize either a carburetor or fuel injection system, depending on the specific variant. These engines are liquid-cooled with a wet sump lubrication system and were typically paired with manual transmissions of 4 or 5 speeds, or automatic transmissions with 3 or 4 speeds. The inherent engineering quality of these engines contributes to their reputation for reliability and longevity. The purpose of this comprehensive English-language workshop service manual is to provide detailed guidance for the maintenance, repair, and technical understanding of the Volvo B17, B19, B21, and B23 engines. It encompasses essential information including recommended service procedures, fluid capacities, and specific maintenance intervals, such as timing belt replacement. Furthermore, the manual offers technical specifications, troubleshooting advice, and diagnostic procedures crucial for both owners performing routine upkeep and professional technicians undertaking complex repairs. This resource is designed to ensure the optimal performance and extended service life of these dependable Volvo engines.