The 1900C engine was developed from high-strength racing block concepts, utilizing an inline
four-cylinder cast iron block with a light alloy cylinder head and dual overhead camshafts (DOHC). A notable
mechanical feature of the 1900's engine was the practical valve clearance adjustment system. The valve
stems, with a diameter of 10 mm, had an internal thread into which a dog-leg shaped tappet was screwed,
eliminating the need to remove the camshafts to change adjustment shims, which greatly facilitated the work
of mechanics and tuners.
Between 1951 and 1959, the 1900C's engines were divided into two main powertrains associated with the
model's generations and updates:
| Performance Specification |
Sprint Version (1.9 Liters - 1951 to 1953) |
Super Sprint Version (2.0 Liters - 1953 to 1959) |
| Block Code |
Type 1306 |
Type 1308 |
| Total Displacement |
1,884 cc |
1,975 cc |
| Bore x Stroke |
82.55 mm x 88 mm |
84.5 mm x 88 mm |
| Compression Ratio |
7.75:1 |
8.0:1 |
| Carburetion |
Single downdraft Solex |
Two Solex 40 PII twin-choke carburetors |
| Maximum Power |
100 hp @ 5,500 rpm |
115 hp @ 5,500 rpm |
| Top Speed |
~180 km/h |
~190 km/h |
| Transmission and Actuation |
4-speed manual (steering column) |
5-speed manual (column or center console) |
The initial Sprint version (1.9 liters) used the same mechanical configuration as the 1900 TI sports
sedan, generating 100 hp to ensure agility in road competitions. In 1953, to honor the dynamic performance
and extract more torque, Alfa Romeo increased the cylinder bore by 2 mm (from 82.55 mm to 84.5 mm), creating
the "Super" engine line of 1,975 cc. In the strongest configuration used in the Super Sprint coupes (CSS),
power was raised to 115 hp with the help of two Solex twin-choke carburetors and larger intake valves, which
went from 38 mm to 41 mm.
From mid-1955, a profound mechanical revision replaced the single chain that drove the camshafts with
two silent chains. This modification reversed the rotation of the camshafts and changed the cylinder firing
order from 1-3-4-2 to 1-2-4-3, improving engine balance. The gearbox also evolved into a 5-speed
transmission synchronized from second to fourth gear, with gear ratios optimized for the power curves of the
Type 1308 powerplant.