Recovery position

Our theoretical look at the comparative speeds of leading cars from 100 years of GP racing. Part 3: post-war resurgence and the start of Formula 1
Words: Mark Hughes. Photography: LAT

1947 Alfa Romeo 158
Index figure: 150
Virtual lap time of the current Spa circuit: 3m 11.9s

They went into a cheese factory hiding place during the war as voiturette racers and emerged as grand prix cars, thanks to the newly-devised Formula 1 category, with half the capacity limit of the pre-war GP formula. Originally developed in the late '30s by Scuderia Ferrari with Alfa's technology, Gioacchio Colombo sited the gearbox at the rear as per the pre-war GP Mercs. For '47 the 1.5-litre, straight-eight was converted from singe- to twin-stage supercharging – upping power from a pre-war 200bhp to 265 bhp.

1948 Alfa Romeo 158D
Index figure: 156.7
Virtual lap time of the current Spa circuit: 3m 06.0s

A bigger supercharger and more exotic fuel brews brought the power up to 310bhp. They dominated, eclipsing Colombo's later design for the new Alfa offshoot, Ferrari, Stiffer drums with vastly better cooling improved braking.

1949 Ferrari 125
Index figure: 154
Virtual lap time of the current Spa circuit: 3m 07.7s

With Alfa withdrawing from competition, it was left to Ferrari to clean up with a development of their original Colombo-designed 125GP, powered by a V12 1.5-litre supercharged motor, the first in GP racing to feature a larger bore than stroke. At the beginning of the season it was still in original single-stage blower/single-cam per bank format. A twin-stage/dohc version made its debut at Monza, upping power to 300bhp at 7500rpm from 225bhp at the same engine speed. The engine never did run at the intended 10,000rpm and with a less sophisticated chassis, and gearbox up front, it was no Alfa-beater.

1950 Alfa Romeo 158D
Index figure: 158.4
Virtual lap time of the current Spa circuit: 3m 02.2s

Alfa came back for the inauguration of the new world championship, still with a development of the '38 'Alfetta'. Original designer Colombo returned to the fold, having fallen out with Enzo Ferrari. Power of the 158D was now up to 350bhp at 8500rpm, with the fuel's alcohol content now being used to help cool the internals, contributing to a consumption of less than 2mpg.

1952 Alfa Romeo 159
Index figure: 164.4
Virtual lap time of the current Spa circuit: 2m 57.0s

Needle roller bearings for the main and big ends brought the revs up to 10,500rmp, aided by a further increase in supercharger boost. Later in the year the swing-axle rear end was replaced by a de Dion, to make the 159A.

1952 Ferrari 500
Index figure: 151.5
Virtual lap time of the current Spa circuit: 3m 10.3s

The adoption of the normally-aspirated 2-litre Formula 2 for the world championship took lap speeds back to 1934 levels. With such a small-capacity limit, engine designer Auerlio Lampredi reasoned the power-to-weight ration would be better with a four- than a multi-cylinder. Installed in a simple chassis with de Dion rear end and rear mounted gearbox, the four-carb, dohc engine had two plugs for each cylinder and produced 170bhp. It won all seven championship grands prix.

1953 Ferrari 500
Index figure: 154.8
Virtual lap time of the current Spa circuit: 3m 06.9s

Very minor changes were made to the 500 for '53 – adding up to an extra 10bhp – and it continued as much as it left off. This time it won seven of the eight championship races.

1954 Mercedes W196
Index figure: 160.5
Virtual lap time of the current Spa circuit: 3m 01.0s

For the new 2.5-litre F1, Mercedes-Benz produced a landmark design, under the guidance of engineer Rudolf Uhlenhaut. It was the first F1 car to utilise a true space-frame chassis. Installed within was a twin-cam straight-eight featuring direct fuel injection — with the mixture fed into the side of the cylinders rather than down a conventional inlet port — and desmodromic valve actuation that did away with valve springs by mechanically operating the exhaust valves as well as the inlets. It was the last successful straight-eight GP engine, and was canted to give a lower bonnet line. Initially, the whole thing was enclosed in a stunning closed-wheel low-drag body. However, an aerodynamic instability at high speeds meant that it frequently ran in more conventional open-wheel form.

1955 Lancia D50
Index figure: 162.5
Virtual lap time of the current Spa circuit: 2m 58.9s

The D50 was the masterpiece of the veteran Vittorio Jano and took as its basis an all-new V8 engine that was used as a stressed member in the chassis — 12 years before the Lotus 49. Pannier tanks ensured weight distribution remained consistent regardless of fuel load.

1956 Lancia-Ferrari D50
Index figure: 166
Virtual lap time of the current Spa circuit: 2m 55.3s

The first car to theoretically better the lap time performance of the 1939 3-litre supercharged Mercedes — with 2.5-litres of unsupercharged V8. This was Ferrari's revision to the departed Lancia model of the previous year. They made what seemed retrograde technical changes — fuel tanks no longer panniers, engine no longer a stressed member — but went quicker regardless, largely thanks to tyre technology advances.

1957 Maserati 250F
Index figure. 169.1
Virtual lap time of the current Spa circuit: 2m 52.1s

Introduced in 1954, it was finally honed to championship success three years later. It accounted for much of the grid on account of being a great privateer's car. Colombo's straightsix dohc engine had been developed to 270bhp by '57.

1958 Vanwall
Index figure. 170.9
Virtual lap time of the current Spa circuit: 2m 50.2s

In '57 Vanwall became the first British car to win a GP since Sunbeam in 1923. For '58, despite new regs that banned exotic nitro and alcohol brews, they were faster. It had a lowdrag body designed by a de Havilland aerodynamicist, a chassis developed with the help of a young Colin Chapman and it was the first title-winning GP car to feature disc brakes.