The Volvo B 23 A is a 2,316 cc, inline‑six naturally aspirated petrol engine produced between 1975 and 1984. It featured an overhead camshaft (OHC) design with a cast iron block and head, marking a significant evolution from the OHV B20. Output ranged from 96 kW (130 PS) to 103 kW (140 PS), with torque figures around 186–196 Nm, providing smooth and refined performance for Volvo's larger sedans.
Fitted primarily to the Volvo 240 Series (242/244/245) and 260 Series, the B 23 A was engineered for enhanced refinement and durability in global markets. Its design incorporated a seven-main-bearing crankshaft and a single overhead camshaft for improved efficiency over its predecessors. Emissions standards for this era varied by market; most units met US Federal or early Euro norms through carburetion and EGR systems.
One documented concern is premature wear of the camshaft lobes and followers, particularly in units with infrequent oil changes, as noted in Volvo Service Bulletin #23A-02. This issue is linked to the metallurgy of early cam components and lubrication quality. The B 23 A was eventually superseded by fuel-injected variants like the B23E and B230 series in the mid-1980s.
Production years 1975–1984 meet US Federal or early Euro 1 standards depending on market and specification (EU Regulation (EC) No 715/2007 historical annex).
The Volvo B 23 A is a 2,316 cc inline‑six naturally aspirated petrol engine engineered for mid‑size and executive sedans (1975-1984). It combines a single overhead camshaft (SOHC) design with a robust seven-main-bearing crankshaft to deliver smooth, reliable performance. Designed to meet contemporary emissions standards, it relies on carburetion and EGR for compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,316 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑6, SOHC, 12‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 88.9 mm × 62.5 mm | |
| Power output | 96–103 kW (130–140 PS) | |
| Torque | 186–196 Nm | |
| Fuel system | Single downdraft carburetor (e.g., Zenith-Stromberg, Carter) | |
| Emissions standard | US Federal / Early Euro 1 (market dependent) | |
| Compression ratio | 9.0:1 – 9.3:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven camshaft | |
| Oil type | SAE 10W-40 (detergent, API SF/CC) | |
| Dry weight | Approx. 185 kg |
The SOHC design offers smoother operation than OHV predecessors but requires periodic valve clearance adjustment. Using high-quality detergent oil (API SF/CC) is critical to prevent premature cam lobe wear as per Service Bulletin #23A-02. The cooling system must be maintained to prevent overheating. The carburetor requires regular tuning for optimal performance and emissions. Parts availability is good through the classic Volvo community.
Oil Specs: Requires API SF/CC specification detergent oil to protect camshaft (Volvo Service Bulletin #23A-02).
Emissions: Certification varies by market (US Federal vs. Early Euro 1) (EU Regulation (EC) No 715/2007).
Power Ratings: Measured under SAE net standards, typical for the era (Volvo Group Historical Archive).
Volvo Service Manual (1978 Edition)
Volvo Technical Bulletin TB-015 (1975)
Volvo EPC Archive Doc. VEP-1975
Volvo Service Bulletin #23A-02
EU Regulation (EC) No 715/2007
The Volvo B 23 A was used across Volvo's 240/260 platforms with longitudinal mounting. This engine received minor updates during its production run, including revised camshaft profiles and carburetor specifications for different markets. All adaptations are documented in OEM technical bulletins.
The engine code "B23" or "B23A" is typically stamped on a flat pad on the block, located on the driver's side near the oil filter or at the rear of the cylinder head. The 7th digit of the VIN is not applicable for this era; identification relies on the physical engine stamp and vehicle model/year. Key visual identifiers include the inline-six configuration, the single overhead cam cover, and the single downdraft carburetor. Differentiation from the B21 is by displacement; the B23 is visibly longer. Differentiation from later fuel-injected B230 engines is by the absence of fuel injectors and associated wiring.
The B 23 A's primary long-term reliability risk is camshaft lobe and follower wear, particularly in units with poor maintenance history. While formal failure statistics are unavailable for this vintage, enthusiast club data and workshop reports consistently cite cam wear, carburetor issues, and cooling system neglect as the most common causes for repair. Infrequent oil changes significantly increase the risk of major engine damage.
Analysis derived from Volvo technical bulletins (1975-1984) and aggregated data from Volvo enthusiast clubs and specialist workshops. Repair procedures should follow manufacturer guidelines where available.
Find answers to most commonly asked questions about VOLVO B-23-A.
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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