BMW M30 / S38 Inline-Six Engine

BMW's M30 "Big Six" is the 2.5–3.5-litre SOHC inline-six that BMW developed from the late 1960s, defining the character of the entire 6-series and M1 era. The M30B30 in the 3.0 CSi (1971) produces 200 hp via Bosch D-Jetronic injection — the first fuel-injected European production car engine. The M88/3 in the M1 (1978) and the E28 M5 (1985) is a double-overhead-cam evolution of the same block architecture, producing 286 hp from 3,453 cc. These three cars share the same block bore centres, crankshaft main bearing spacing, and engine-bay mounting geometry — a 20-year design lineage.