Ferrari Colombo engine
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Colombo engine in a 1961 250TR Spider
|Cylinder block alloy||Aluminium|
|Cylinder head alloy||Aluminium|
|Cooling system||Water cooled|
|Successor||Ferrari flat-12 engine|
Colombo had formerly designed Alfa Romeos for Enzo Ferrari. These V12 powerplants ranged from the diminutive 1.5 L (1497 cc) unit fitted to the 125S to the 4.9 L (4943 cc) unit in the 1986 412i. Significant updates were made in 1963 for the 330 series featuring a redesigned block with wider bore spacing.
Enzo Ferrari had long admired the V12 engines of Packard, Auto Union, and Alfa Romeo (where he was long employed), but his first car, the 1940 Auto Avio Costruzioni 815, used a Fiat straight-8. Ferrari's first homegrown engine was a V12 designed by Colombo, with development continuing long after original designer Colombo had been replaced by Aurelio Lampredi as the company's marquee engine designer. Although Lampredi's engines were a real force for the company, it was Colombo's V12 which would be the primary motivator for the company's consumer products through the 1950s and 1960s.
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.
- 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)
58.8 mm stroke
The early 166, 195, and 212 cars used Colombo V12s of varying sizes. All shared the same 58.8 mm (2.3 in) stroke, with 60, 65, and 68 mm (2.7 in) bores giving displacements of 1995, 2341, and 2563 cc in the 166, 195, and 212 respectively. Output ranged from 105 hp (78 kW) to 165 hp (123 kW).
One of the most common Colombo engines is the 250. It bowed in 1952 in the 250S and lasted through the 1963 330 America. It used a 73 mm (2.9 in) bore with the common Colombo stroke of 58.8 mm (2.3 in) for a total of 2953 cc.
The final 58.8 mm (2.3 in) Colombo Ferrari was the 275. It used a 3286 cc variant of the V12 with a wide 77 mm (3.0 in) bore for up to 300 hp (224 kW).
The 1960 400 Superamerica replaced the previous model's Lampredi engine with a 3967 cc Colombo. It diverged from the standard 58.8 mm (2.3 in) stroke with a 71 mm (2.8 in) stroke and 77 mm (3.0 in) bore. Output was 340 to 400 hp (298 kW) with triple Weber carburetors.
Although the 1963 330 series also used a 3967 cc engine with the same bore and stroke as the 400 Superamerica, this engine was quite different. It used a wider bore spacing, paving the way for future displacement increases. The spark plugs were moved and a new water pump was used. The dynamo on the prior versions was replaced by a true alternator. In the end, 300 hp (223 kW) was on tap.
The Colombo V12 was substantially reworked for 1967's 275 GTB/4. It still used two valves per cylinder, but dual overhead cams were now used as well. In a departure from previous Ferrari designs, the valve angle was reduced three degrees to 54° for a more-compact head. The dual camshafts also allowed the valves to be aligned "correctly" (perpendicular to the camshaft) instead of offset as in SOHC Ferraris. It was a dry-sump design with a huge 17 qt (16 L) capacity. The engine retained the bore and stroke dimensions of the 275 model for 3286 cc of displacement. Output was 330 hp (246 kW) at 8000 rpm and 240 lb·ft (325 Nm) at 6000 rpm with six Weber 40 DCN 9 carburetors.
The 330 Colombo engine was enlarged with an 81 mm (3.2 in) bore to 4390 cc for 1966's 365 California, retaining single overhead cams and wet sump lubrication. A reworked engine with four camshafts was used in the GT/4 models. The 365 GTB/4 Daytona was the only 365 engined car featuring dry sump lubrication.
- 1966–1967 365 California
- 1968–1970 365 GTC, 365 GTS
- 1968–1972 365 GT 2+2
- 1968–1973 365 GTB/4 Daytona, 365 GTS/4 Daytona
- 1971–1972 365 GTC/4
- 1972–1976 365 GT4 2+2
The wet sump, four-cam, 365 Colombo engine was enlarged again to 4823 cc for 1976's 400 with the same 81 mm (3.2 in) bore and a 78 mm (3.1 in) stroke. The carburetors were replaced with Bosch K-Jetronic fuel injection in 1979. In 1986 the engine was bored to 82 mm giving a displacement of 4943 cc.