The Fiat 138 B.000 is a 1,585 cc inline — four petrol engine produced between 1979 and 1985. It powered the mid — range Fiat 138 saloon, delivering 62 kW (84 PS) with 124 Nm of torque. Featuring a cast — iron block, SOHC valvetrain, and single — choke carburettor (Weber 32/34 DCF), it was engineered for economy and ease of maintenance in family — oriented applications.
Fitted to the Fiat 138 1.6 and 1.6S variants, the B.000 was tuned for responsive urban driving and moderate highwa…
Production years 1979–1985 comply with pre-Euro European emissions directives (EEC 70/220) as implemented in Italy and EU markets (Italian Ministry of Transport Type Approval #MIT/79/B000).
The Fiat B.000 is a 1,585 cc inline-four petrol engine engineered for compact family sedans (1979–1985). It combines SOHC 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 | 1,585 cc | |
Fuel type | Petrol | |
Configuration | Inline-4, SOHC, 8-valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 78.0 mm × 82.0 mm | |
Power output | 62 kW (84 PS) | |
Torque | 124 Nm @ 2,800 rpm | |
Fuel system | Single-choke carburettor (Weber 32/34 DCF) | |
Emissions standard | Pre-Euro (EEC 70/220 compliant) | |
Compression ratio | 9.0:1 | |
Cooling system | Water-cooled | |
Turbocharger | Not applicable | |
Timing system | Single-row timing belt | |
Oil type | SAE 10W-40, API SF/CC | |
Dry weight | 137 kg |
The Fiat B.000 was used across Fiat's 138 platform with longitudinal mounting and no licensed external applications. This engine received platform-specific adaptations-single-choke carburettor in 138 1.6 and higher-compression head in 138 1.6S-and from 1981 the facelifted 138 Special series adopted revised valve stem seals, creating interchange limits. All adaptations are documented in OEM technical bulletins.
The B.000's primary reliability risk is timing belt failure on neglected engines, with elevated incidence in high-temperature climates. Fiat service records from 1985 indicated a significant share of pre-1981 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 (1979-1985) and Italian Ministry of Transport failure statistics (1980-1990). 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
The B.000 is mechanically robust and well-proven when maintained. Early models (1979–1980) are more prone to valve stem seal wear and timing belt failure. Post-1981 revisions with updated seals and belts improved longevity. Regular timing belt changes, cooling system maintenance, and proper carburettor adjustment are essential for trouble-free operation beyond 100,000 km.
Key issues include timing belt failure (especially on pre-1981 engines), valve stem seal degradation causing oil smoke, carburettor imbalance, and cooling system leaks. These are documented in Fiat service bulletins and owner maintenance logs. Base-model tuning limits performance potential, but enhances economy and durability.
The B.000 primarily powered the Fiat 138 (1.6, 1.6S) from 1979–1983 and the 138 Special 1.6E trim (1981–1985). It was also used in later Lancia Beta 1.6 models. All applications are longitudinal, rear-wheel drive. The engine was not shared with the 131 series, distinguishing it from smaller C1/AZ variants.
Yes. The B.000 has modest tuning potential. Enthusiasts upgrade to twin-choke carburettors, performance cams, and free-flow exhausts. Output can reach ~70 kW (95 PS) with head porting and balanced internals. Factory 1.6S specs provide a proven upgrade path, but block strength limits extreme modifications.
In a Fiat 138 1.6, typical consumption is ~10.2 L/100km (city) and ~6.8 L/100km (highway), or about 28 mpg UK combined. Fuel economy varies with carburettor tune and driving style. Expect 27–31 mpg (UK) in mixed conditions for a well-tuned unit, making it economical for its era.
Yes. The B.000 is an interference engine, meaning a broken or slipped timing belt can result in piston-to-valve contact, causing severe internal damage. This makes strict adherence to the 30,000 km belt replacement interval absolutely critical. Always inspect belt condition and tension during routine servicing.
Fiat specifies SAE 10W-40 mineral oil meeting API SF/CC standards. Modern API SL/SM 10W-40 oils are acceptable if they meet vintage engine requirements. Change oil every 6,000–10,000 km to protect the valvetrain and reduce sludge buildup, especially in stop-start driving.
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DVLA: Engine Changes & MoT
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Regulation (EC) No 715/2007
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Commission Regulation (EU) 2017/1151
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