Ferrari Colombo Engine - 125

The first homegrown Ferrari engine was the 125. First appearing May 11, 1947 under the hood of Ferrari's 125 S sports racer, the engine allowed the company to claim six victories in 14 races that year. The 125 S sported tiny 55.0 mm (2.2 in) by 52.5 mm (2.1 in) cylinders, the resulting 124.73 cc of each cylinder rounded up to give the engine, and the car, its name. Overall, the engine displaced exactly 1,496.77 cc (91 in³). It had a single overhead camshaft on each bank of cylinders with a 60° angle between the two banks. The engine had two valves per cylinder fed through three Weber 30DCF carburettors. A 7.5:1 compression ratio yielded 118 hp (88 kW) at 6800 rpm.

Colombo and Ferrari had designed the engine with Formula One regulations in mind, and introduced it the next year in the company's first F1 car, the 125 F1. This time, it was supercharged, in accordance with F1 dictates, for a total output of 230 hp (172 kW) at 7,000 rpm. However, the Roots-type single-stage supercharger was incapable of producing the high-end power required to compete with the strong eight-cylinder Alfa Romeo 158 and four-cylinder Maserati 4CLT. Strong driving and a nimble chassis, however, allowed the company to place third in its first outing, at the Valentino Grand Prix on September 5, 1948 and the company persevered in racing.

For 1949, the engine was further modified with dual overhead camshafts (though still two valves per cylinder) and a two-stage supercharger. This combination gave the car better top-end performance and the resulting 280 hp (209 kW) gave it five Grand Prix wins. Development continued the following year, but the problematic superchargers were dropped in favor of larger displacement and Lampredi's 275 engine superseded the original Ferrari engine.

Applications:

• 1947 Ferrari 125 S — 118 hp (88 kW)
• 1948 Ferrari 125 F1 — Single supercharger, 230 hp (172 kW)
• 1949–1950 Ferrari 125 F1 — Dual-stage supercharger, 280 hp (209 kW)