| Alfa Romeo Boxer engine | |
| Manufacturer: | Alfasud (Alfa Romeo) (1971-1986) Alfa-Lancia Industriale (1987-1991) Fiat Auto (1991-1997) |
| Production: | 1971 - 1997 |
| Configuration: | Naturally aspirated Flat-4 |
| Block: | Cast iron |
| Head: | Aluminium alloy |
| Valvetrain: | DOHC 2 or 4-valve |
| Fuelsystem: | 1 or 2 carburetors Fuel injection |
| Oilsystem: | NaNL |
| Power: | NaN0NaN0 |
| Coolingsystem: | Water-cooled |
| Fueltype: | Petrol |
| Management: | Bosch LE 3.1 Jetronic or Motronic ML 4.1 |
| Successor: | Twin Spark engine |
| Emissions Control: | Catalytic converter (on 1700 16V) |
The Alfa Romeo Boxer engine was a water-cooled flat-4 piston engine, developed by Alfa Romeo for front-wheel drive, and longitudinal applications.It debuted on the Alfasud, which was introduced in 1971 at the Turin Motor Show.[1] In the following decades the Boxer went through several upgrades and powered many Alfa Romeo front-wheel drive cars up to 1996 (not the 164). In 1997 it was phased out and replaced by the transversely-mounted Twin Spark engines.
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 or two 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.[2]
The fuel delivery system depended on version: a single-barrel downdraft carburetor; one or two double-barrel downdraft carburetors; Bosch LE 3.1 Jetronic fuel injection (8 valve engines).;[3] or Bosch Motronic ML 4.1 fuel injection (16 valve engines).[4]
The original engine displaced 1186cc (72 cu.in.) with an NaNmm bore and stroke and produced between 63and.[5]
Applications:
The engine was stroked up to 64mm to create the 1286cc version. This engine produced 68-. A version of this engine (engine type 901.U0) was fitted with a catalytic converter, air injection, and evaporative emissions controls and received Californian emissions certification in 1976. The Alfasud was nonetheless never exported to the United States.
Applications:
The 1351cc was usually labelled a "1.3" in spite of its displacement. It produced 75- with one or two double-barrel carburettors.[9] It retained the 80mm bore but used the 1500s 67.2mm crankshaft.
Applications:
From 1978 until October 1986, the largest member of the family was the 1490cc "1500" with NaNmm bore and stroke. It was built until 1995 and produced 84to. This is the largest engine to have been installed in Alfasuds.[12]
Applications:
The 1596cc produced 1030NaN0. Bore and stroke is NaNmm.[13]
Applications:
In October 1986 the engine was increased in size to 1712cc (104 cu.in), it was used in the 33 and later Sprints, power was between 105and. Bore and stroke is NaNmm.
Applications:
In January 1990 a quad-cam 16-valve version of the venerable boxer was introduced; it was the most powerful to date, with 129- with or without catalytic converters. Only available in fuel-injected form, the 1.7 16V was equipped with the Bosch Motronic ML 4.1 system.
The last Alfa Romeo flat-four engine was produced in 1997, after a run of 26 years.
Applications: