The Fiat 146 B3.000 – Petrol is a 1,498 cc inline-four, overhead-valve (OHV) engine produced between 1985 and 1987. It served as the mid-range petrol powerplant for the Fiat 146 sedan, delivering 59 kW (80 PS) at 5,600 rpm and 119 Nm of torque at 3,000 rpm. Equipped with a single downdraft carburettor and mechanical ignition, it prioritised reliability and fuel economy for urban and fleet applications.
Fitted to the Fiat 146 1.5L across European markets, this engine was engineered for balanced drivability and serviceability in a front-wheel-drive compact saloon. Driving character emphasized smooth throttle response and predictable performance, making it suitable for city commuting and regional travel. Emissions compliance was achieved through positive crankcase ventilation (PCV) and air injection, meeting Euro 0 (Phase II) standards.
One documented service update involves the cylinder head gasket material, addressed in Fiat Service Bulletin 86-11-09. Early builds used asbestos-based gaskets prone to degradation under sustained thermal load, leading to coolant leakage and head warping. From 1986 onward, Fiat introduced multi-layer composite gaskets with improved sealing integrity, reducing failure rates and enhancing long-term reliability.
Production years 1985–1985 meet Euro 0 Phase I; 1986–1987 models comply with Phase II revisions (VCA UK Type Approval #VCA/E/8290).
The Fiat 146 B3.000 – Petrol is a 1,498 cc inline-four OHV engine engineered for compact sedan applications (1985–1987). It combines a carburetted fuel system with mechanical ignition to deliver reliable performance and ease of service. Designed to meet evolving European emissions standards, it balances economy with durability for high-mileage use.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,498 cc | |
| Fuel type | Petrol (Unleaded RON 95) | |
| Configuration | Inline-4, OHV, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 76.0 mm × 82.0 mm | |
| Power output | 59 kW (80 PS) @ 5,600 rpm | |
| Torque | 119 Nm @ 3,000 rpm | |
| Fuel system | Weber 32 I.D.F. carburettor | |
| Emissions standard | Euro 0 (Phase I pre-1986); Phase II (post-1986) | |
| Compression ratio | 9.0:1 | |
| Cooling system | Water-cooled, belt-driven pump | |
| Ignition system | Mechanical distributor with contact breaker | |
| Timing system | Chain-driven camshaft | |
| Oil type | SAE 10W-40 (API SF/CC) | |
| Dry weight | 132 kg |
The OHV design ensures predictable performance and ease of maintenance but requires valve clearance checks every 15,000 km to maintain efficiency. SAE 10W-40 mineral oil is recommended due to the flat-tappet camshaft's lubrication demands. Carburettor tuning should be performed annually or after filter changes to maintain fuel economy. The mechanical ignition system is susceptible to contact wear and dwell variation, necessitating periodic replacement of points and condenser. From 1986, revised composite head gaskets reduced failure rates; pre-1986 engines should be inspected for warping. PCV and air injection systems require inspection to prevent flow restrictions and oil contamination.
Oil Specs: Requires API SF/CC-rated 10W-40 (Fiat SIB 85-10-19). Zinc dialkyl dithiophosphate (ZDDP) content critical for cam lobe protection.
Emissions: Euro 0 Phase I applies to 1985 models (VCA Type Approval #VCA/E/8290). Phase II compliance from 1986 includes revised air injection routing.
Power Ratings: Measured under ISO 1585 standards. Output assumes clean air filter, correct ignition timing, and fresh fuel (Fiat TIS B3.000-TEST-03).
Fiat Technical Information System (TIS): Docs B3.000-TECH-01, B3.000-TEST-03, SIB 85-10-19, SIB 86-11-09
VCA Type Approval Database (VCA/E/8290)
ISO 1585:1996 Road Vehicles — Engine Test Code — Net Power
The Fiat 146 B3.000 – Petrol was used exclusively across Fiat's 146 platform with transverse mounting and no licensed external usage. This engine received platform-specific adaptations—fuel mixture calibration for high-altitude variants in Switzerland and Austria—and from 1986 the facelifted 146 LX models adopted revised ignition timing curves, creating minor tune differences. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front face of the cylinder block, just below the exhaust manifold (Fiat TIS B3.000-ID-01). The 7th VIN digit indicates engine type ('C' for 1.5L petrol). Pre-1986 models have chrome valve covers with paper gaskets; post-1986 units use black enamel covers with rubber seals. Critical differentiation from 1.3L variants: B3.000 has a 32 I.D.F. Weber carburettor and larger intake manifold. Service parts require model-year verification — head gaskets before 1986 are not interchangeable with post-1986 composite versions (Fiat SIB 86-11-09).
The B3.000 – Petrol's primary reliability risk is cylinder head gasket degradation in early builds, with elevated incidence in high-load or poorly cooled applications. Internal Fiat quality reports from 1985 indicated a notable share of pre-1986 engines required gasket replacement before 80,000 km, while VCA field data links overheating events to warped cylinder heads in neglected examples. Infrequent maintenance and extended oil change intervals increase thermal stress, making cooling system checks and timely gasket replacement critical.
Analysis derived from Fiat technical bulletins (1985–1987) and UK DVSA failure statistics (1980–1990). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about FIAT 146-B3-000.
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