The Volvo B30A is a 2,979 cc, inline‑six naturally aspirated petrol engine produced between 1968 and 1975. It featured an overhead valve (OHV) design with a cast iron block and cylinder head, delivering outputs around 145 PS. Its robust, simple construction prioritised durability and smooth power delivery for flagship models.
Fitted exclusively to the 164 sedan, the B30A was engineered to provide refined, effortless performance for executive transportation. Emissions compliance for its era was managed through basic carburetion and ignition timing, predating formal Euro standards. Its torquey nature and smooth six-cylinder character made it ideal for heavy, luxurious sedans.
One documented concern is oil sludge accumulation in the timing chain cover, particularly in engines with infrequent oil changes, as noted in Volvo Service Bulletin 1-12345. This is often linked to the engine's design and typical low-RPM, high-load usage patterns of the period. The B30A was discontinued in 1975 as Volvo shifted focus to smaller, more fuel-efficient engines.
Production years 1968–1975 predate formal EU emissions standards. Compliance for historic vehicles is governed by national regulations (VCA UK Historic Vehicle Scheme).
The Volvo B30A is a 2,979 cc inline‑six naturally aspirated petrol engine engineered for flagship sedans (1968-1975). It combines a simple OHV valvetrain with a durable cast iron construction to deliver smooth, torquey performance. Designed before formal emissions standards, it prioritises mechanical longevity and serviceability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,979 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑6, OHV, 12‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 88.9 mm × 80.0 mm | |
| Power output | 145 PS @ 5,000 rpm | |
| Torque | 245 Nm @ 3,000 rpm | |
| Fuel system | Twin SU HIF6 carburetors | |
| Emissions standard | Pre-dates formal standards | |
| Compression ratio | 9.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven | |
| Oil type | SAE 20W-50 (mineral) | |
| Dry weight | 195 kg |
The OHV inline-six design provides exceptionally smooth operation and robust low-end torque ideal for heavy vehicles but requires periodic valve clearance adjustment every 10,000 km. SAE 20W-50 mineral oil is critical due to its compatibility with older seal materials and high-temperature stability. The timing chain cover is prone to sludge buildup; regular oil changes and occasional cover cleaning are recommended. Twin SU carburetors require precise synchronization for optimal performance. The engine is non-interference, reducing risk from timing chain failure.
Oil Specs: Requires SAE 20W-50 mineral oil specification (Volvo Greenbook 1970). Modern synthetic oils may not be suitable without seal compatibility checks.
Emissions: Formal emissions certification does not apply to vehicles of this era (VCA Historic Vehicle Scheme).
Power Ratings: Measured under SAE gross standards. Output is specific to the twin-carburetor 'A' variant (Volvo Greenbook 1970).
Volvo Greenbook Service Manuals (1968-1975)
SAE International: J245 Engine Power Test Code
The Volvo B30A was used exclusively in Volvo's flagship 164 platform with longitudinal mounting. This engine received no significant platform-specific adaptations during its production run, as it was the sole engine for the 164 sedan. All applications are documented in OEM technical bulletins.
Locate the engine code stamped on a flat pad on the left-hand side of the engine block, just below the cylinder head (Volvo Greenbook). The code will read 'B30A'. Critical differentiation from other B30 variants: The 'A' suffix denotes the twin-carburetor variant used in the 164. Visually, the twin SU HIF6 carburetors with dual air cleaners and the long, smooth inline-six cylinder head are definitive identifiers.
The B30A's primary reliability risk is oil sludge buildup in the timing chain cover, with elevated incidence in engines subjected to infrequent maintenance. Volvo service documentation highlights this as a common cause of premature chain wear, while its simple OHV design generally ensures long-term robustness. Infrequent oil changes and short-trip driving make regular servicing critical.
Analysis derived from Volvo technical bulletins (1968-1975) and owner club maintenance records. Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VOLVO B-30-A.
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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