The Fiat Pratola Serra modular engines (also known as family B engines for the 4-cylinder units, and family C engines for the 5-cylinder units) are a family of engines produced by the Fiat Group since 1994 and used in Fiat, Alfa Romeo, Lancia and Jeep vehicles. They are named after the Pratola Serra municipality in which they're being produced.

Overview This new engine family debuted with the Lancia Kappa, and were designed to allow the production of different units, both diesel and petrol, in various displacements and configurations while decreasing development and production costs thanks to the modular architecture.

Five cylinder launch versions: DisplacementBore x StrokeCycleNoteOttoNaturally aspirated, variable valve timingOttoNaturally aspirated, variable valve timing, variable-length intake manifoldDieselTurbocharged

These engines are produced in the FGA's FMA (Fabbrica Motori Automobilistici) factory in Pratola Serra. It's an advanced factory, with a production capacity of 600,000 engines/year and producing both petrol and Diesel engines.

Started in 1993, it was developed to produce multiple engines with a single production line, sharing components between them.

In 2010 the Chinese GAC Group started production of 1.8 and 2.0 Alfa Romeo Twin Spark 16V configurations of the Pratola Serra modular engine branded as "VTML" in China. These engines constitute however unique configurations, mating the single spark plug cylinder head from the 1.8 16V VFD to the 1747 and 1970 Twin Spark engine blocks, the latter with balance shafts, while retaining the power levels of the Twin Spark 16V. While these engines have been phased out in the European market in favor of the 1.4 MultiAir Turbo gasoline engine, part of the smaller Fiat FIRE series, they have later been updated with dual variable valve timing (branded "DCVVT") and turbochargers, and are as of 2016 used in Trumpchi automobiles.

Engine specifications Engine blocks are produced in four- and five-cylinder versions with similar specs, usually made from cast iron, with five main bearings for the four cylinder versions and six main bearings for the five cylinder versions. Exceptions are the later version of the petrol and the diesel four-cylinder blocks, made from aluminum. They are developed to withstand turbocharging. Some versions have counter-rotating balance shafts to reduce vibrations. The aluminium pistons have graphite skirts to reduce internal engine friction.

Cylinder heads are made in aluminum alloy. Petrol versions have an integrated coolant pump and pentroof combustion chambers with an angle of 47° between valves. The turbodiesels have a different, flat combustion chamber design.

They usually have a DOHC valvetrain configuration with hydraulic tappets, driving four valves per cylinder. Exceptions are the 1.4 12V unit, also with hydraulic tappets but a SOHC valvetrain, driving three valves per cylinder, and the 1.9 8V and 2.4 10V turbodiesels, with a SOHC valvetrain with mechanical tappets, driving two valves per cylinder. The 1750 TBi gasoline and 16V Multijet diesel engines feature hydraulic tappets with roller rocker arms. Some versions feature variable valve timing (VVT). The camshafts are belt-driven.

In addition to VVT, some versions also feature variable-length intake manifold (VIS).

Earlier Alfa Romeo versions use the Twin Spark ignition system. There is also a version of the four cylinder block using direct injection, used only in Alfa Romeo's vehicles, dubbed as JTS.

In Brazil, the 5-cylinder petrol engines equipped the Marea sedan and station wagon (Marea Weekend) lines between 1998 and 2006, including a 2.0 20V with deactivated VVT (125 PS) for lower taxation, 2.0 20V VVT (140 PS), 2.4 20V with VVT and VIS (157 PS) and a turbocharged 2.0 20V (180 PS) — detuned from the 220 PS version from Fiat Coupé. A slightly updated version of the 2.4 20V was also used on the Stilo Abarth with 165 PS.

Engine blocks DisplacementBore x StrokeCylindersCycleBlock alloy4OttoCast iron4OttoCast iron4OttoEarly units: cast iron Later units: aluminum4OttoCast iron4OttoCast iron4DieselCast iron4DieselCast iron4DieselCast iron5OttoCast iron4DieselAluminum4DieselCast iron5OttoCast iron5DieselCast iron

Current production DisplacementBore x StrokeCylindersCycleConfigurationPower output4Otto16V DOHC, dual VVT, turbocharged, gasoline direct injection, aluminum block in later versions4Diesel16V DOHC, turbocharged, Multijet II common-rail injection4Diesel16V DOHC, turbocharged, Multijet II common-rail injection4Diesel16V DOHC, turbocharged, Multijet II common-rail injection, aluminum block4Diesel16V DOHC, turbocharged, Multijet II common-rail injection

Fiat applications Petrol unitsTypeVehicles1.4 12VBravo I, Brava, Marea1.8 16V Bravo I, Brava, Marea1.8 16V VFDPunto II HGT, Barchetta, Coupé, Stilo, Brava HGT (South America)2.0 20V Bravo I, Marea, Coupé2.0 20V Turbo Marea (South America), Coupé2.4 20V Marea (South America), Stilo AbarthDiesel unitsTypeVehicles1.6 Multijet/Multijet II 16VGrande Punto, Bravo II, Doblò, Linea, 500L, 500X, Tipo1.9 D/TD/JTD/Multijet 8V/16VBravo I, Brava, Marea, Multipla, Palio, Strada, Punto, Stilo, Doblò, Idea, Grande Punto, Sedici, Bravo II2.0 Multijet/Multijet II 16VBravo II, Sedici, Freemont, Doblò, Ducato2.2 L (2,184 cc)2.2 Multijet III 16VDucato2.4 TD/JTD/Multijet 10V/20VMarea, Croma

Lancia applications Petrol unitsTypeVehicles1.4 12VYpsilon1.8 Di T-Jet 16VDelta III1.8 16V VFDDedra, Delta II, Lybra2.0 20VKappa, Lybra, Thesis2.4 20VKappa, Lybra (Protecta), ThesisDiesel unitsTypeVehicles1.6 Multijet 16VMusa, Delta III1.9 JTD/Multijet 8V/16VLybra, Musa, Delta III (twinturbo)2.0 Multijet 16VDelta III2.4 TD/JTD/Multijet 10V/20VKappa, Lybra, Thesis

Alfa Romeo applications Petrol unitsTypeVehicles1.4 Twin Spark 16V145, 1461.6 Twin Spark 16V Eco 1471.6 Twin Spark 16V 155, 145, 146, 156, 1471750 TBi159, 4C, Giulietta, Brera, Nuova Spider1.8 Twin Spark 16V155, 145, 146, GTV, Spider, 156, GT2.0 Twin Spark 16V155, 145, 146, GTV, Spider, 156, 166, 1472.0 JTSGTV, Spider, 156, GTDiesel unitsTypeVehicles1.6 JTDm/JTDm2 16VMito, Giulietta, Tonale1.9 JTD/JTDm 8V/16V145, 146, 156, 147, GT, 1592.0 JTDm/JTDm2 16V159, Brera, Spider, Giulietta2.2 JTDm2 16VGiulia, Stelvio2.4 JTD/JTDm 10V/20V166, 156, 159, Brera, Nuova Spider

Jeep applications Diesel unitsTypeVehicles1.6 Multijet II 16VRenegade (BU)2.0 Multijet 16VCherokee (KL), Renegade (BU)2.2 Multijet II 16VWrangler (JL)2.2 Multijet II 16VCherokee (KL)

Applications in other brands Petrol unitsTypeVehicles1.6 16V DCVVTTrumpchi GA3/GA3S, Trumpchi GA5, Trumpchi GA61.8 16V DCVVTTrumpchi GA5, Trumpchi GA6, Trumpchi GS5 Super2.0 16V DCVVTTrumpchi GA5, Trumpchi GS5 SuperDiesel unitsTypeVehicles1.6 Common RailOpel Combo D1.9 Common RailOpel Zafira, Saab 9-3, Cadillac BLS2.0 Common RailOpel Astra, Opel Insignia, MG Hector, Tata Harrier, Tata Safari

See also Alfa Romeo Twin Cam engine Alfa Romeo Twin Spark engine Fiat Twin Cam engine Fully Integrated Robotised Engine JTD engine