The Lancia Aurelia 2.5L is a 2,451 cc, 60° V6 petrol engine produced between 1950 and 1958. It was the world's first production V6 engine for a passenger car, featuring a single overhead camshaft per bank and an innovative aluminum alloy block. In standard B20 GT form it delivered approximately 90 kW (120 PS), providing brisk performance for its era.
Fitted exclusively to the Lancia Aurelia series (B10 sedan, B20 GT coupe, B24 Spider), this engine was engineered for refined g…

This engine predates formal EU emissions regulations. Production years 1950–1958 fall outside the scope of modern type approval (VCA UK, EU Regulation 715/2007).
The Lancia Aurelia 2.5L is a 2,451 cc 60° V6 petrol engine engineered for grand tourers (1950-1958). It combines a single overhead camshaft per bank with an aluminum alloy block to deliver smooth, refined power. Designed before formal emissions standards, its architecture focused on mechanical innovation and drivability.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,451 cc | |
Fuel type | Petrol | |
Configuration | 60° V6, SOHC per bank, 12-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 82.55 mm × 76.0 mm | |
Power output | 90 kW (120 PS) @ 5,200 rpm | |
Torque | 186 Nm @ 3,000 rpm | |
Fuel system | Twin-choke Weber 40 DCL5 carburetor | |
Emissions standard | Pre-regulation era | |
Compression ratio | 8.5:1 | |
Cooling system | Water-cooled | |
Turbocharger | None | |
Timing system | Chain-driven single overhead camshaft per bank | |
Oil type | SAE 20W-50 mineral oil (period specification) | |
Dry weight | Approx. 165 kg |
The Lancia Aurelia 2.5L V6 was used exclusively in Lancia's Aurelia platform with longitudinal, front-mounted installation. This engine received platform-specific adaptations-different carburetion and final drive ratios for the B20 GT coupe versus the B24 Spider-and was never licensed to other manufacturers. All adaptations are documented in OEM technical bulletins.
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The Aurelia 2.5L's primary long-term concern is corrosion in the aluminum engine block and cylinder head, with elevated incidence in humid climates or with neglected coolant. Lancia service records from the 1960s noted frequent head gasket failures on high-mileage examples, while owner club surveys highlight carburetor tuning difficulties. Regular coolant changes and meticulous maintenance are critical for preservation.
Analysis derived from Lancia technical bulletins (1950-1960) and Lancia Aurelia Owner's Club maintenance surveys (2010-2020). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
As a pioneering 1950s engine, its long-term reliability depends entirely on meticulous, expert maintenance. The aluminum construction is robust but prone to corrosion if coolant is neglected. With proper care, including regular oil and coolant changes, these engines can run reliably for decades. Parts scarcity is the main challenge for owners today.
The most common issues are corrosion in the aluminum block/head, wear in the camshaft timing chains, and tuning difficulties with the original Weber carburetor. Electrical gremlins from the aged wiring system are also frequent. These are well-documented in Lancia service manuals and owner club resources.
The 2.5L V6 was fitted to the final series of Lancia Aurelia models: the B10 Berlina sedan (1954-1958), the B20 GT coupe (1954-1958), and the rare B24 Spider America (1954-1955). It was never used in any other Lancia model or by another manufacturer.
Yes, within limits. Common period modifications included higher-compression pistons, performance camshafts, and dual carburetors. Modern tuning is possible but complex due to parts scarcity. Significant power gains risk overstressing the original drivetrain components, which were designed for the factory output.
Fuel economy is modest by modern standards. Expect around 15-18 L/100km (15-13 mpg UK) in mixed driving for a B20 GT. The B24 Spider, being lighter, might achieve slightly better figures. Economy is heavily influenced by carburetor condition and driving style.
Yes. Like most overhead cam engines, it is an interference design. If the timing chain fails or jumps, the pistons will collide with the open valves, causing catastrophic internal damage. This makes regular inspection and replacement of the timing chain absolutely critical.
The original specification was SAE 20W-50 mineral oil. For modern use, a high-quality 20W-50 mineral or semi-synthetic oil designed for classic engines is recommended. Regular oil changes (every 5,000 km or annually) are essential for preserving the engine's internals and timing system.
Comprehensive technical documentation and regulatory references
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Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
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
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
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