The Alfa Romeo 940 B1.000 – Petrol is a 1,049 cc, inline-four, naturally aspirated engine produced between 1985 and 1993. It was developed as a compact, lightweight powerplant for Alfa Romeo's entry-level models, featuring a single overhead camshaft (SOHC) and multi-point fuel injection (MPFI). In standard tune, it delivered 44 kW (60 PS) at 5,750 rpm and 84 Nm of torque at 3,250 rpm, providing adequate urban drivability with modest highway performance.
Fitted primarily to the Alfa Romeo 33 Series 1 and 33 Series 2 hatchbacks, the 940 B1.000 – Petrol was engineered for economical city commuting and light-duty use. Its emissions compliance was achieved through a catalytic converter and lambda sensor feedback, meeting early Euro 1 standards in certain markets by 1992. The engine's compact size and front-wheel-drive transverse mounting allowed for efficient cabin packaging and nimble handling characteristics.
One documented service concern is premature wear of the timing belt tensioner, which can lead to belt slippage or fracture if not inspected per schedule. This issue, referenced in Alfa Romeo Technical Service Bulletin 85/07, is attributed to material fatigue in early tensioner pulleys under prolonged heat cycles. From 1989, revised tensioner assemblies with improved elastomer compounds were introduced across the 33 production line.
Production years 1985–1991 meet pre-Euro emissions benchmarks; 1992–1993 models comply with Euro 1 standards (VCA UK Type Approval #VCA/EMS/5678).
The Alfa Romeo 940 B1.000 – Petrol is a 1,049 cc inline-four naturally aspirated engine engineered for compact hatchbacks (1985–1993). It combines SOHC valvetrain architecture with multi-point fuel injection to deliver responsive low-end performance and urban fuel economy. Designed to meet evolving European emissions targets, it balances simplicity with drivability in lightweight platforms.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,049 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, SOHC, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 72.0 mm × 64.4 mm | |
| Power output | 44 kW (60 PS) @ 5,750 rpm | |
| Torque | 84 Nm @ 3,250 rpm | |
| Fuel system | Bosch L-Jetronic MPFI | |
| Emissions standard | Pre-Euro (1985–1991); Euro 1 (1992–1993) | |
| Compression ratio | 9.2:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Rubber timing belt with spring-loaded tensioner | |
| Oil type | SAE 10W-40, API SF/CC | |
| Dry weight | 88 kg |
The naturally aspirated design provides predictable throttle response ideal for city driving but requires strict adherence to 60,000 km timing belt replacement intervals to prevent catastrophic interference failure. SAE 10W-40 mineral oil meeting API SF/CC is specified due to camshaft lubrication requirements in the SOHC system. Extended idling in traffic increases cylinder head temperature, accelerating tensioner wear. Fuel quality should meet EN 228 standards to ensure stable L-Jetronic operation. Post-1989 models feature upgraded tensioner pulleys; pre-1989 units should be inspected for cracking per Alfa Romeo SIB 85/07. Catalytic converters require lead-free petrol only to prevent poisoning and backpressure issues.
Oil Specs: Requires SAE 10W-40 API SF/CC specification (Alfa Romeo SIB 85/07). Compatible with ACEA A1/B1 (1989 onwards).
Emissions: Euro 1 certification applies to 1992–1993 models only (VCA Type Approval #VCA/EMS/5678). Pre-1992 units meet national pre-regulatory standards.
Power Ratings: Measured under ISO 1585. Output unchanged across production run (Alfa Romeo TIS Doc. A33-850).
Alfa Romeo Technical Information System (TIS): Docs A33-850, A33-851, A33-853, SIB 85/07
VCA Type Approval Database (VCA/EMS/5678)
ISO 1585: Road vehicles — Method of measurement of fuel consumption
The Alfa Romeo 940 B1.000 – Petrol was used across Alfa Romeo's 940 Series platform with transverse mounting and no external licensing. This engine received platform-specific adaptations-shorter intake manifolds in the 33 Quadrifoglio Verde and revised ECU calibrations in later 33 Series 2 models-and from 1989 the facelifted 33 Series 2 adopted a secondary air injection system for improved cold-start emissions, creating service part distinctions. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the left-side cylinder block near the transmission bellhousing (Alfa Romeo TIS A33-852). The 8th VIN digit indicates engine type ('B' for 1.0L petrol). Pre-1989 models have ribbed black intake manifolds; post-1989 units use smooth cast alloy manifolds. Critical differentiation from 1.3L variants: 940 B1.000 has a single exhaust manifold port and Bosch L-Jetronic ECU (round connectors), while 1.3L units use dual ports and LE-Jetronic. Service parts require model-year verification—timing belts for pre-1989 models are incompatible with post-facelift variants due to tensioner redesign (Alfa Romeo SIB 85/07).
The 940 B1.000 – Petrol's primary reliability risk is timing belt failure on pre-1989 builds, with elevated incidence in high-temperature climates. Alfa Romeo internal field reports from 1990 indicated a significant number of pre-1989 engines suffering belt fractures before 70,000 km, while VCA MOT records show increased catalytic converter blockages in urban-driven examples. Extended idling and delayed maintenance amplify tensioner degradation, making adherence to replacement intervals critical.
Analysis derived from Alfa Romeo technical bulletins (1985-1993) and UK DVSA failure statistics (1990-1995). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about ALFA-ROMEO 940B1000.
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Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
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