Alfa Romeo Flat-4 engine

Overview
Manufacturer	Alfa Romeo
Production	1971–1997
Combustion chamber
Configuration	DOHC 2/4-valve F4
Displacement	1,186 cc 1,286 cc 1,351 cc 1,490 cc 1,596 cc 1,712 cc
Cylinder block alloy	cast-iron
Cylinder head alloy	aluminium alloy
Combustion
Fuel system	1 or 2 carburetor Bosch LE 3.1 Jetronic
Fuel type	Petrol
Oil system	4-4,5 L
Cooling system	Watercooled
Output
Power output	63 PS (46 kW)-137 PS (101 kW)

Alfa Romeo developed a water-cooled flat-4 engine for their new Alfasud, introduced in 1971 at the Turin Motor Show.

This Liquid-cooled, four cylinder, boxer (horizontally opposed) engine had a belt-driven water pump. Its integrated cast iron cylinder block and crankcase had three main bearings. The two aluminum alloy crossflow cylinder heads had one overhead camshaft in each, driven by individual timing belts, and two valves per cylinder (four valves per cylinder in the 1700 16V version). Wet sump lubrication.

The fuel delivery system depended on version: a single-barrel downdraft carburetor; one or two double-barrel downdraft carburetors; or Bosch LE 3.1 Jetronic fuel injection.

Alfa Romeo Flat-4 engine Applications

1200

The original engine displaced 1.2 L (1,186 cc) with an 80 mm bore and 59 mm stroke and produced between 63 and 77 PS (46 and 57 kW).

• 1971-1983 Alfa Romeo Alfasud
• 1984-1986 Alfa Romeo Arna
• 1984-1986 Nissan Cherry Europe (rebadged Alfa Romeo Arna, sold also as Nissan Pulsar Milano in Japan)
• 1983-1986 Alfa Romeo 33 (late versions for export only)

1300

The engine was stroked (to 64 mm) to create the 1.3 L (1,286 cc) version. This engine produced 68–75 PS (50–55 kW).

• 1977-1983 Alfa Romeo Alfasud
• 1977-1983 Alfa Romeo Sprint

1400

The 1.4 L (1,351 cc) was usually labelled a "1.3" in spite of its displacement. It produced 75–86 PS (55–63 kW) with one or two double-barrel carburettors. It retained the 80 mm bore but used the 1500's 67.2 mm crankshaft.

• 1978-1983 Alfa Romeo Alfasud
• 1978-1989 Alfa Romeo Sprint
• 1983-1995 Alfa Romeo 33
• 1994-1997 Alfa Romeo 145
• 1995-1997 Alfa Romeo 146

1500

From 1978 until October 1986, the largest member of the family was the 1.5 L (1,490 cc) "1500" (84.0 x 67.2 mm bore and stroke). It was built until 1995 and produced 84 to 105 PS (62 to 77 kW). This is the largest engine to have been installed in Alfasuds.

• 1978-1983 Alfa Romeo Alfasud
• 1978-1989 Alfa Romeo Sprint
• 1984-1986 Alfa Romeo Arna
• 1983-1995 Alfa Romeo 33
• 1985-1986 Clan Clover
• 1984-1986 Nissan Cherry Europe

1600

The 1.6 L (1,596 cc) produced 103 PS (76 kW). Bore and stroke is 84.0 x 72.0 mm.

• 1994-1997 Alfa Romeo 145
• 1995-1997 Alfa Romeo 146

1700

In October 1986 the engine was increased in size to 1.7 L (1,712 cc), it was used in the 33 and later Sprints, power was between 105 and 118 PS (77 and 87 kW). Bore and stroke is 87.0 x 72.0 mm.

• 1986.10-1995 Alfa Romeo 33
• 1986.10–1989 Alfa Romeo Sprint

1700 16V

In January 1990 a quad-cam 16-valve version of the venerable boxer was produced; it was the most powerful to date, with 129–137 PS (95–101 kW) with or without catalytic converters. Only available in fuel-injected form, the 1.7 16V was equipped with the Bosch ML 4.1 Motronic system.

The last Alfa Romeo flat-4 was produced in 1997, after a run of 26 years.

• 1990.01-1995 Alfa Romeo 33 (2nd generation)
• 1994-1997 Alfa Romeo 145
• 1995-1997 Alfa Romeo 146

The Alfa Romeo Flat-4 boxer engine