Fiat Pratola Serra modular engines

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 "comune" where they are produced.

Story

This new engine family debuted with the Lancia Kappa, and was born to allow the production of different units in various displacements and configurations while decreasing development and productions costs thanks to the modular architecture.

Launch versions:

Displacement (cc)	Bore (mm)	Stroke (mm)	Cylinders	Cycle	Note
1998	82	75.65	5	Otto	Naturally aspirated, variable valve timing
2446	83	90.40	5	Otto	Naturally aspirated, variable valve timing, variable-length intake manifold
2387	82	90.40	5	Diesel	Turbocharged

They replaced the Fiat Twin Cam and Alfa Romeo Twin Cam engines.

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. The achieved result is that 8 different cylinder blocks are produced on the same line, that can in turn be coupled with 8 different crankshafts (5 different steel ones and 3 different cast iron ones), 15 different camshafts, 9 different cylinder heads, 6 different connecting rods, 5 different flywheels and 10 different intake manifolds, for a total of 90 possible engines.

Engine specifications

Engine blocks: produced in four- and five-cylinder versions, they have similar specs. They are cast iron, with five main bearings for the four cylinder versions and six main bearings for the five cylinder versions, and can withstand turbocharging. Some versions have counter-rotating balance shafts to reduce vibrations. The aluminium pistons have graphite skirts to reduce internal engine friction, providing more reliability and efficiency.

Cylinder heads: built in aluminium alloy, they have an integrated coolant pump and lightly asymmetric combustion chambers with an angle of 47° between valves. The 1.9 8v e 2.4 10v turbodiesels have a different combustion chamber design, with two parallel valves per cylinder and a flat rather than angled design.

They have a DOHC valvetrain configuration with hydraulic tappets, driving four valves per cylinder. An exception is the 1.4 12V unit, also with hydraulic tappets but a SOHC valvetrain driving three valves per cylinder. The 1.9 8V e 2.4 10V turbodiesels have a SOHC valvetrain configuration with mechanical tappets. Some versions have variable valve timing (VVT). The camshafts are toothed belt-driven. In addition to VVT, some versions have also variable-length intake manifold (VIS).

Behavior

Variable Valve Timing optimizes the engine's intake stroke, boosting thermal efficiency and achieving a broader and more regular torque curve.

The hydraulic tappets reduce noise levels and also maintenance needs.

Variable-length intake manifold improves the volumetric efficiency of the engine, providing better performance in the whole engine speed range.

Engine blocks

Displacement (cc)	Bore (mm)	Stroke (mm)	Cylinders	Cycle
1370	82	64.87	4	Otto
1581	82	75.65	4	Otto
1747	82	82.70	4	Otto
1970	83	91	4	Otto
1598	79.50	80.50	4	Diesel
1910	82	90.40	4	Diesel
1956	83	90.40	4	Diesel
1998	82	75.65	5	Otto
2184	83.8	99	4	Diesel
2446	83	90.40	5	Otto
2387	82	90.40	5	Diesel

Applications on FIAT vehicles

Petrol units (cc)	Type	Vehicles
1370	1.4 12V	Bravo I, Brava, Marea
1747	1.8 16V 115PS	Bravo I, Brava, Marea
1747	1.8 16V 131PS	Punto II HGT, Barchetta, Coupé, Stilo
1998	2.0 20V	Bravo I, Marea, Coupé
2446	2.4 20V	Marea (South America), Stilo Abarth
Diesel units (cc)	Type	Vehicles
1598	1.6 Multijet/Multijet II 16V	Grande Punto, Bravo II, Doblò, Linea, 500L, 500X, Tipo
1910	1.9 D/TD/Jtd/Multijet 8V/16V	Bravo I, Brava, Marea, Multipla, Palio, Strada, Punto, Stilo, Doblò, Idea, Grande Punto, Sedici, Bravo II
1956	2.0 Multijet/Multijet II 16V	Bravo II, Sedici, Freemont, Doblò, Ducato
2387	2.4 TD/JTD/Multijet 10V/20V	Marea, Croma

Applications on Lancia vehicles

Petrol units (cc)	Type	Vehicles
1370	1.4 12V	Y
1747	1.8 16V 131PS	Dedra, Delta II, Lybra
1998	2.0 20V	K, Lybra, Thesis
2446	2.4 20V	K, Lybra (Protecta), Thesis
Diesel units (cc)	Type	Vehicles
1598	1.6 Multijet 16V	Musa, Delta III
1910	1.9 JTD/Multijet 8V/16V	Lybra, Musa, Delta III (twinturbo)
1956	2.0 Multijet 16V	Delta III
2387	2.4 TD/JTD/Multijet 10V/20V	K, Lybra, Thesis

Applications on Alfa Romeo vehicles

Petrol units (cc)	Type	Vehicles
1370	1.4 Twin Spark 16V	145, 146
1598	1.6 Twin Spark 16V	155, 145, 146, 156, 147
1747	1.8 Twin Spark 16V	155, 145, 146, GTV, Spider, 156, GT
1970	2.0 Twin Spark 16V	155, 145, 146, GTV, Spider, 156, 166, 147, GT
1970	2.0 JTS	GTV, Spider, 156, GT
Diesel units (cc)	Type	Vehicles
1598	1.6 JTDm/JTDm2 16V	Mito, Giulietta
1910	1.9 JTD/JTDm 8V/16V	145, 146, 156, 147, GT, 159
1956	2.0 JTDm/JTDm2 16V	159, Brera, Spider, Giulietta
2184	2.2 JTDm2 16V	Giulia
2387	2.4 JTD/JTDm 10V/20V	166, 156, 159, Brera, Nuova Spider

Applications on Jeep vehicles

Diesel units (cc)	Type	Vehicles
1956	2.0 Multijet 16V	Cherokee (KL)
2184	2.2 Multijet II 16V	Cherokee (KL)

Applications on other vehicles

Diesel units (cc)	Type	Vehicles
1598	1.6 Common Rail	Opel Combo D
1910	1.9 Common Rail	Opel Zafira, Saab 9-3, Cadillac BLS
1956	2.0 Common Rail	Opel Astra, Opel Insignia