The Fiat 131 C1.000 is a 1,438 cc inline-four petrol engine produced between 1974 and 1984. It powered the base and mid-trim Fiat 131 saloon and estate variants, delivering 54–62 kW (73–84 PS) depending on compression ratio and carburettor setup. Featuring a cast-iron block, SOHC valvetrain, and single-choke carburettor, it was engineered for economy and ease of maintenance in family-oriented applications.
Fitted to the Fiat 131 range—including the Mirafiori and Familiare models—the C1.000 was tuned for responsive urban driving and moderate highway cruising. Its design prioritized fuel efficiency and low maintenance costs, making it suitable for European markets with high fuel prices. Emissions control was achieved via controlled combustion and early evaporative emission systems, meeting pre-Euro standards applicable during its production run.
One documented engineering update occurred in 1977, referenced in Fiat Service Information Bulletin C1-77-02, involving revised piston ring tension to reduce oil consumption in high-mileage engines. This update improved long-term durability and was retrofittable to earlier builds, reflecting Fiat's incremental development strategy during the 1970s.
Production years 1974–1984 comply with pre-Euro European emissions directives (EEC 70/220) as implemented in Italy and EU markets (Italian Ministry of Transport Type Approval #MIT/74/C1000).
The Fiat C1.000 is a 1,438 cc inline-four petrol engine engineered for compact family sedans and wagons (1974–1984). It combines SOHC valvetrain architecture with single-choke carburetion to deliver balanced performance and mechanical simplicity. Designed to meet early emissions regulations, it balances economy with serviceability for daily driving applications.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,438 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-4, SOHC, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 76.0 mm × 79.0 mm | |
| Power output | 54–62 kW (73–84 PS) | |
| Torque | 108–116 Nm @ 2,800 rpm | |
| Fuel system | Single-choke carburettor (Weber 32/34 DCF or Solex 32 PAIA) | |
| Emissions standard | Pre-Euro (EEC 70/220 compliant) | |
| Compression ratio | 8.8:1 (standard), 9.2:1 (S-model) | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Single-row timing belt | |
| Oil type | SAE 10W-40, API SF/CC | |
| Dry weight | 135 kg |
The SOHC design ensures predictable performance and ease of maintenance but requires strict adherence to 30,000 km timing belt replacement intervals to prevent valve damage. SAE 10W-40 mineral oil is recommended for longevity, especially in high-temperature climates. Carburettor models need periodic adjustment of idle mixture and choke operation. The 1977 piston ring update (Fiat SIB C1-77-02) should be verified or installed to reduce oil consumption in older units. Cooling system integrity is critical due to cast-iron block expansion characteristics.
Oil Specs: Requires SAE 10W-40 API SF/CC specification (Fiat SIB C1-77-02). Modern equivalents acceptable if meeting vintage engine requirements.
Emissions: Pre-Euro compliance under EEC 70/220 directive applies to all models (Italian Ministry of Transport #MIT/74/C1000). No Euro standards existed during production period.
Power Ratings: Measured under UN ECE Regulation 85. Output varies by carburettor tune and compression ratio (Fiat Group PT-1975-C1).
Fiat Technical Information System (TIS): Docs C1.000-ME-001, C1.000-FUEL-02, SIB C1-77-02
Italian Ministry of Transport Type Approval Database (MIT/74/C1000)
European Commission: EEC Directive 70/220/EEC
UN ECE Regulation 85: Power Measurement Standards
The Fiat C1.000 was used across Fiat's 131 platform with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-single-choke carburettor in 131 Normale and higher-compression head in 131 S-and from 1977 the facelifted 131 Special series adopted a revised ignition system, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the right-side engine block near the starter motor (Fiat TIS C1.000-ME-001). The 7th VIN digit indicates engine type ('C' for C1 series). Pre-1977 models have chrome valve covers; post-1977 units use black-painted covers. Critical differentiation from AZ.000: C1.000 uses a smaller bore (76.0 mm vs 80.0 mm) and single-choke carburettor. Service parts require model-year verification—timing belts for pre-1977 engines are not compatible with post-1977 revisions due to pulley diameter changes (Fiat SIB C1-77-02).
The C1.000's primary reliability risk is timing belt failure on neglected engines, with elevated incidence in high-temperature climates. Fiat service records from 1982 indicated a significant share of pre-1977 units required belt replacement before 30,000 km due to cracking, while Italian MOT archives show valve train damage as a leading cause of engine seizure. Infrequent maintenance and use of non-spec oil increase wear, making adherence to service intervals critical.
Analysis derived from Fiat technical bulletins (1975-1984) and Italian Ministry of Transport failure statistics (1980-1990). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about FIAT 131-C1-000.
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