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 grand touring with smooth power delivery and low vibration. Emissions standards were not formally regulated during its production, though its design inherently offered cleaner combustion than many contemporary engines.
One documented engineering evolution is the increase in displacement from 1.8L to 2.5L across the Aurelia's lifecycle, accompanied by revisions to the cylinder head and camshaft profiles for improved power. This progression is detailed in Lancia's internal factory service notes and parts catalogues from the period.
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 60° V6 layout provides exceptionally smooth operation ideal for long-distance touring but requires precise valve timing adjustment and regular lubrication of the camshaft chains. Period-correct SAE 20W-50 mineral oil is recommended for authenticity, though modern equivalents are acceptable. The aluminum block is susceptible to corrosion if coolant is not maintained. Twin-Weber carburetors demand expert tuning for optimal performance and fuel economy. Parts availability is limited, requiring specialist suppliers or fabrication.
Oil Specs: Requires SAE 20W-50 mineral oil as per 1954 workshop manual. Modern multi-grade oils are a practical substitute.
Emissions: Formal emissions certification did not exist for this era (Pre-EU Regulation 715/2007).
Power Ratings: Measured under period dynamometer standards. Output varies slightly between Aurelia B20 GT and B24 Spider applications.
Lancia Aurelia Workshop Manual (1954 Edition)
Lancia Technical Archive Documents (LA-50-01, LA-55-02)
Lancia Factory Specifications Sheet (1955)
EU Regulation (EC) No 715/2007 (for historical context)
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.
The engine code is typically not stamped on early Aurelia engines; identification is by displacement (2451cc) and application (B10, B20, B24). The 60° V6 with twin cam covers and a single carburetor is visually distinctive. Differentiate from the 2.0L by the larger bore size (82.55mm vs. 80mm). Critical parts like the cylinder head and camshaft are specific to the 2.5L variant and not interchangeable with earlier 1.8L or 2.0L units without modification. Consult the Lancia parts catalogue by chassis number for precise verification.
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.
Find answers to most commonly asked questions about LANCIA AURELIA-2-5L-V6.
Comprehensive technical documentation and regulatory references
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LANCIA Official Site
Owner literature, service manuals, technical releases, and plant documentation.
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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