The Volvo B 21 E is a 2,127 cc, inline‑four naturally aspirated petrol engine produced between 1975 and 1984. It features a single overhead camshaft (SOHC) and two valves per cylinder, delivering improved torque and refinement over its B20 predecessor. The engine’s robust cast-iron block and simple valvetrain prioritized durability and ease of maintenance.
Fitted primarily to the Volvo 240 and 260 series sedans and wagons, the B 21 E was engineered for dependable, economical daily transportation with enhanced drivability. Emissions compliance for its production period was managed through carburetor tuning, ignition controls, and in later models, basic fuel injection, aligning with mid-to-late 1970s regulatory standards.
One documented concern is premature camshaft and rocker arm wear, particularly under low-oil-change conditions — a carryover issue from earlier B-series engines. Volvo Service Bulletin 21E-78 addressed this with revised camshaft metallurgy and lubrication recommendations. Later B21 variants (B21A, B21F, B21FT) incorporated fuel injection and turbocharging for improved performance and emissions.
Production years 1975–1984 meet applicable emissions standards for their model year and market of sale (EU Directive 70/220/EEC as amended, transitioning to Euro 1).
The Volvo B 21 E is a 2,127 cc inline‑four petrol engine engineered for mid-size sedans and wagons (1975-1984). It combines a durable SOHC valvetrain with a downdraft carburetor to deliver improved torque and smoothness while maintaining mechanical simplicity. Designed to meet evolving 1970s-1980s emissions standards, it balances everyday performance with serviceability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,127 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑4, SOHC, 8‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 96.0 mm × 73.6 mm | |
| Power output | 75–85 kW (102–116 PS) | |
| Torque | 165–175 Nm @ 3,500 rpm | |
| Fuel system | Single downdraft carburetor (e.g., Zenith-Stromberg 175CD) | |
| Emissions standard | Late 1970s EU/US standards, evolving to early 1980s standards | |
| Compression ratio | 9.3:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven camshaft | |
| Oil type | SAE 15W-40 or 20W-50 mineral oil | |
| Dry weight | 150 kg |
The B 21 E inherits the B-series camshaft wear susceptibility — vigilance in oil maintenance (every 5,000–8,000 km) is essential. Use high-detergent mineral oil (SAE 15W-40/20W-50) to prolong rocker and cam life. Carburetor tuning is critical for smooth idle and emissions compliance; periodic cleaning and jet adjustment are recommended. Pre-1978 units benefit from camshaft upgrades per SB 21E-78. Ignition timing must be checked quarterly for optimal performance and emissions.
Oil Specs: Requires detergent mineral oil (SAE 15W-40 or 20W-50) (Volvo Owner's Manual 1975). Modern synthetics not originally specified.
Emissions: Compliance based on EU Directive 70/220/EEC amendments applicable to model year. No formal Euro standard existed until 1992.
Power Ratings: Measured under SAE gross or DIN standards per period norms (Volvo PT-1978). Output varies by carburetor and market (e.g., US-spec models slightly detuned).
Volvo Technical Information System: Workshop Manuals 240/260 Series
Volvo EPC (Electronic Parts Catalogue) Documentation
EU Directive 70/220/EEC on motor vehicle emissions
Volvo Service Bulletin 21E-78
The Volvo B 21 E was used across Volvo's 240 and 260 platforms with longitudinal mounting. Minor carburetor and ignition tuning occurred for different markets, but no major platform-specific adaptations affect core compatibility. All variants share the same block, head, and mounting points. Adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on a flat boss on the left-hand side of the engine block, just below the cylinder head and near the front engine mount (Volvo Workshop Manual). The code will read "B21" followed by a letter suffix (e.g., B21E, B21A) indicating specific market or carburetor configuration. Visually, it is a cast-iron block engine with a single cam cover and a carburetor mounted on the intake manifold. It is distinct from the B20 by its larger bore (96.0mm vs 88.9mm) and from later B23 engines by its smaller displacement. Service parts for the B 21 E are generally compatible across all 240/260 applications from 1975-1984, but carburetor jets and distributor curves may vary by market.
The B 21 E's primary reliability risk is camshaft and rocker arm wear — a legacy issue from the B18/B20 platforms. Volvo service data shows this was a leading cause of valve train rebuilds in late 1970s models. Additionally, carburetor gumming, vacuum leaks, and distributor wear are common with age. Strict adherence to maintenance intervals is critical for longevity.
Analysis derived from Volvo technical bulletins (1975-1984) and aggregated workshop repair data. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VOLVO B-21-E.
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VOLVO Official Site
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EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
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VCA Certification Portal
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