Lancia Flat-4 engine

Lancia introduced its new aluminum flat-4 engine in 1960 for the Flavia. Though it was a pushrod engine, it was advanced for the time. 

The pushrod version of the Lancia boxer was only ever used in the Flavia, and its derivatives including the Lancia 2000. In 1976, a new overhead cam engine based on a similar layout was designed and brought into production in 2 and 2.5 litre forms fitted to the Gamma.

Pushrod

1500

The original version was the 1500 cc introduced in 1960; it used an 82 mm bore and 71 mm stroke. It was revised on 1963 with a smaller 80 mm bore and a longer 74 mm stroke, thus displacing 1488 cc. A final version was introduced in 1967 with an even longer 80 mm stroke coupled with a 77 mm bore, giving a displacement of 1490 cc. Production ceased in 1970.

1800

The first 1800 was a 1.7 L (1727 cc) introduced in 1962. It used an 88 mm (3.5 in) bore and 71 mm (2.8 in) stroke. One year later it was replaced by a true 1.8 L (1800 cc) engine thanks to a longer 74 mm (2.9 in) stroke. In 1967 appeared the 1816 cc version using an 85 mm stroke with an 80 mm bore.

2000

The 2.0 L (1991 cc) 2000 version was the ultimate Flavia engine. Bore was 89 mm (3.5 in) and stroke was 80 mm (3.1 in) for a good oversquare ratio. In 1971, the 2.0 L produced 115 bhp (86 kW; 117 PS),and in the HF Coupe in 1972 it produced 125 bhp (93 kW; 127 PS). This engine was produced from 1968 through 1974.

OHC

Lancia developed the large light-alloy overhead camshaft 2.0-litre and 2.5-litre flat-4 engines specifically for the Lancia Gamma, rather than using Fiat derived engines as used in the Beta and Montecarlo and were in production between 1976 and 1984.

2000

Replacing the 2.0 L pushrod engine used in the Flavia, the new 2.0 L OHC (1999 cc) engine produced 120 bhp (89 kW; 122 PS) @ 5500rpm and 172 N⋅m (127 lb⋅ft) torque @ 3500rpm.

2500

The 2.5 L (2484 cc) engine was initially available with twin-choke Weber carburettors, but in the last few years of production it was equipped with fuel injection. In both forms, it produced 140 bhp (104 kW; 142 PS) @ 5400rpm and 208 N⋅m (153 lb⋅ft) torque @ 3000rpm.