Alfa Romeo Boxer engine

The Alfa Romeo Boxer is a water-cooled flat-four piston engine that Alfa Romeo developed for front-wheel-drive cars with a longitudinal engine layout. It debuted in the Alfasud, shown at the 1971 Turin Motor Show, and over the following decades was enlarged and revised to power a range of the company's front-wheel-drive models until 1996 or 1997, when the transversely mounted Twin Spark engines replaced it. The design used an integrated cast iron block and crankcase with three main bearings and two aluminium alloy cylinder heads with overhead camshafts, with two valves per cylinder and a four-valve 1.7 litre version added in 1990. Displacements ran from 1.2 to 1.7 litres, and fuel supply moved from carburettors to Bosch fuel injection.