Alfa Romeo 158/159

X-ray spec

The beautiful Alfetta was a post-war sensation. Only one is still racing. Keith Howard quizzes the man who knows it inside-out – Tony Merrick

Very few Italians would be inclined to acknowledge it, but the unique competition record of the Alfa 158, the original Alfetta, arguably owes as much to the rise of National Socialism in Germany as to the talents of its legendary designer Gioachino Colombo.

There are two reasons for this: first, it was conceived in 1937 to compete in the 1.5-litre Voiturette formula, thereby sidestepping the Nazi-funded silver steamroller which was flattening all opposition in grand prix racing; second, it was put on ice during WWII (if you can be put on ice in a cheese factory), recovering quickly from its enforced hibernation to continue its winning ways while the rest of Europe emerged hesitantly into what was purportedly a new spring. The key Italian contribution, having created such a fine racing car in the first instance, was continually to find ways to improve it, particularly in the engine department.

When the 158 won on its debut, at Livorno in August 1938, its supercharged 1480cc straight-eight with unfashionably undersquare cylinder dimensions developed about 195bhp at 7000rpm, equivalent to 132bhp per litre. By the time, as the modified 159, it scored its (and Alfa's) last grand prix win on its final appearance, at Pedralbes in October 1951, with Fangio at the wheel, the fitment of progressively larger superchargers — now force-feeding the engine at just under 3bar! — had raised its output to a heroic 420bhp at 9300rpm, a remarkable 284bhp per litre. The little Alfa had grown during its 13-year reign to become almost, but not quite, as fearsome as the Mercedes and Auto Unions which had provoked its birth.

A total of six 158s were built, to which were added four 159s in 1951. Among other changes, the latter had longer tails incorporating a larger fuel tank to help assuage the engine's now prodigious thirst. This was the year Colombo returned to Alfa from Ferrari, so his contribution to the modifications was probably minimal; colleague Orazio Satta is credited with the major role. Whoever conceived them, they were just enough to secure Fangio the championship in the face of stiff competition from Ferrari. But Alfa knew well enough that the Alfetta had been living on borrowed time. Hero to zero, it simply withdrew from GP racing at the end of the season, until its inauspicious return 28 years later.

Colombo died in 1987, so for some insight into the 158's design I approached top restorer Tony Merrick, who for some years has prepared Carlo Vogele's Alfetta for historic racing. Tony has also driven it "for a few laps around Silverstone, but not in anger" so has some feel for the car from behind the wheel.

Merrick and Colombo met once, briefly, at the Italian GP in 1976.

"I'd got a photograph of a P3 Alfa that I'd taken with me for some reason, a car I'd just finished doing and had photographed in Richmond Park," says Merrick. "Colombo signed it on the back, not on the front, because he hadn't designed the car. He wrote that he was signing it in lieu of Jano, which I thought was really nice."

In a sense, Merrick now returns the favour, albeit with reference to a cutaway of the 159. Would Colombo have signed this picture on the front, I wonder?

X-ray spec: Alfa Romeo 158/159

"Brakes are aluminium drums with cast-iron inserts, twin leading shoes front and rear, and extremely effective. The drums are a larger diameter at the front to achieve the required brake balance, although later cars had them all the same size. We were struggling with brakes three years ago, couldn't find a lining material to cope. We get pretty bloody awful support from the friction material manufacturers, which I'm sad about, but we've sorted it now. Carlo's mechanic came across a brake material that the Swiss army uses and it's just amazing."

"The cockpit gets quite warm because of the oil tank by your left leg, but otherwise it's one of the most comfortable grand prix cars I've ever sat in. You could drive it for hours. Everything is in just the right place; it seems a lot of consideration was given to the driver. I've also had a little drive in a Mercedes W125 and I don't know how the drivers put up with it. Its seat is seriously uncomfortable, bolt upright, whereas the Alfa's is nicely angled. But the 158's solid propshaft runs at engine speed only a few millimetres below the underside of the seat, so it needs to be running true!"

"The 158 is unusual in having telescopic as well as friction dampers at both ends; the telescopic ones are hung off the chassis and work when they open. Although the hydraulic dampers are adjustable, it's a lengthy process, so you set them to a norm and make final adjustments with the friction units."

One of the changes made to later cars was a reinforcing of the chassis to increase stiffness. "See the side rail running front to rear, through the bulkhead? We don't have that, and of course the triangulations are missing too. I'm astonished how narrow the chassis is – it's a ladder-type made of elliptical main tubes only 360mm apart. You can see how close they are beneath the driver's seat in the drawing. It isn't very good if you have a side impact but it's actually quite stiff because the engine is a stressed member with 20 mounting bolts, and the transaxle is the same."

"For such a powerful car the gearbox is really quite small – the gear cluster is just 5in ling. They achieved it by having first and second on the layshaft and third and fourth on the main shaft. So it's compact but strong. And beautifully made – not quite as good as the Mercedes 300SLR or W196, which is the most incredible gearbox I've ever seen, but similar in quality. It's a super gearchange to use as well, and your hand falls straight to it off the steering wheel."

This 159 is fitted with de Dion rear suspension (the other three had swing axles), an arrangement tried on the experimental 158D in which head test driver Attilio Marinoni lost his life in an autostrada accident in 1940. Other 158s, like the other 159s, had swing axles. "The swing-axle rear means that if you start off with a full fuel load you have negative camber. As the race goes on the camber becomes more positive which makes things exciting, since with all that poke the car is tail-happy anyway. We don't really notice it because we only do 10-lap races, but ina three- or four-hour race you'd notice it a few times, before each refuelling."

"The main engine oil tank is by the driver's left leg. There is a fuel tank on the other side which we use to carry a small amount of petrol, whereas in the main rear tank it's all methanol. Having finished a race or a weekend you change the tap over and run the engine on petrol until it goes black in the exhaust, then you know you'll have no problems with corrosion or solidifying of the fuel, which can be a real pain with methanol."

"The air intake we have on Carlo's car is the earlier 'elephant's trunk', which curves forwards from the carburettor – a beautiful piece of art. It picks up warmer air from the engine bay, which is probably not a bad idea in that you tend not to suffer icing of the carburretors, which you can with high-performance methanol engines. This 159 is fed via the small flap in front of the screen. Probably Alfa made the change because colder inlet air means more power. It's pretty thirsty: we get about a mile to the gallon! The triple-choke Weber carburretor was designed for the car and has two main jets of 3.9mm diameter – that's where all the fuel goes. The engine is supposed to deliver about 420bhp at 9300rpm but we don't run to those revs. I'm sure we could, but we don't. We saw something around 400bhp at 8500 on our dyno."