PETROL ENGINE FOUNDATIONS 1930–1989

This chapter is a readable companion to ../../databases/ENGINE_MASTER_DATABASE.md. The database is authoritative for normalized row identity; this chapter explains lineage.

Pre-war line

BMW's official inline-six history establishes a clear factory lineage: M78 (303) → larger derivatives → M328 and M335. Earlier Dixi-derived four-cylinder automobile engines are retained as technical configurations without invented BMW code labels.

M337 and the 1950s

The BMW 501 post-war I6 is explicitly identified as M337 in BMW's engine history. The 1950s V8 is historically crucial as BMW's all-light-alloy production V8, but this pass does not assign a code until a primary BMW engine document states it unambiguously.

M10

BMW's own history gives the M10 family a 1962–1988 backbone role. It appears in many displacements and tunes, so the Engine Master splits actual technical states instead of creating a single “M10” super-row. The 2002 turbo is a turbocharged M10 road revision, not a separate unrelated family.

M06 / M30 naming layer

The 1968 large-six began as M06 in BMW historical nomenclature. The 1971 3.0-litre carburettor and injection variants are described as M21 and M20 in the same official history, before later nomenclature consolidated the large-six family as M30. Those period codes are preserved.

M60 / M20 naming layer

The compact six introduced for the E21 is documented as M60 and later renamed M20. This historic M60 must never be confused with the unrelated V8 family carrying the M60 designation in the 1990s.

M88 and S14

M88 connects the M1 to M635CSi/M5 via M88/3. S14 is represented by road-homologation revisions rather than race-engine power figures. Motorsport-only outputs remain outside the road Engine Master.

1987–1989 architecture shift

M40 replaced the old M10-era four-cylinder architecture in key E30 applications. M42B18 added a 16-valve DOHC head in 1989. M50 sits on the редакционная глава/019 boundary and is only entered here as the new-family launch state.