chapter 5
This page is dedicated to the memory of Pat Braden who died on August 25, 2002.
Chapter 6
Racing Politics
In telling the story of Alfa, it's occasionally possible to talk about race
and passenger cars in the same breath. Other times, the two paths diverge
so significantly that one has to follow simultaneous but distinctly
separate threads. Until 1923, Alfa's story is a monofilament of sporty
passenger cars which were easily adapted for racing simply by removing
most of the bodywork. Remember that the early cars were little more
than chassis given over to specialist carrozeria for embodiment, anyway.
The 1914 Alfa Grand Prix car was singularly unsuccessful and so
doesn't unravel the singular thread of Alfa's history. But, beginning
in 1923, significant developments in race car design require separate
attention.
The direction of racing history has been shaped as much by the politics
of its governing bodies as technology. The governing bodies have always
been French, and generally committed to achieving French supremacy in
racing. That they have failed to do so is a commentary on French
engineering.
The very first automobile events, the Gordon Bennett Cup, were
administered by the Auto Club of France (ACF), and specified only that
all the components of the car be indigenous. Since France was the largest
world-wide producer of cars, the formula almost guaranteed French
supremacy. The ACF went on to control race-car specifications until the
early 1920s, when it was replaced by another French organization, the
AIACR (International Association of Auto Clubs). Formulas restricting
race-car weight, engine capacity, fuel consumption, frontal area and even
number of persons aboard were all tried in an effort to moderate speeds.
Each regulation served to produce only more clever ways of increasing
speeds.
In 1921, the ACF decreed a maximum displacement of 3 liters. Fiat
constructed an entirely new car, the Type 801, with a twin-cam engine
following the lines of the 1912 Peugeot. The Grand Prix Fiats became
dominant and, when the formula was reduced to 2 liters in 1922,
continued their domination with the 804, which produced 112 hp at 5000
rpm. For 1923, Fiat introduced the supercharged 8-cylinder 805 car. With
130 hp at 5500 rpm, two 805s made a 1-2 sweep of the European Grand
Prix at Monza, the first grand prix won by a supercharged car.
Supercharged cars would continue to reign supreme until 1952, when the
FIA decreed an unsupercharged formula.
In Fiat's wake, other manufacturers, Alfa Romeo included, were just
trying to play catch-up. In 1923, Fiat 6-cylinder work-alikes were
introduced by Sunbeam as well as Alfa Romeo. It is clear that Merosi
was uncomfortable designing racing cars. When he was asked to design
a "modern" grand prix engine, he simply updated his work on the
Henri-inspired 1914 GP. The GPR of 1923 was not
even sorted out when
Ugo Sivocci crashed in one and was killed. Romeo was intent on
competing successfully in the grands prix and set about to find a designer
who could make him a winning car. At the peak of his passenger-car
efforts, Merosi was fired for want of a good race car.
One of the Fiat designers, Vittorio Jano, was lured away from his
beloved Turin with an offer which doubled his Fiat salary. His
appearance at Alfa was hardly noticed, but as he walked through the
drafting room, he tapped a young draftsman to be his assistant: Luigi
Fusi. Jano's first action, evidently, was to supercharge the GPR with a
Wittig-type blower similar to the units used on the Fiats. But he quickly
grew uncomfortable with Merosi's design.
In several weeks of intensive work, Fusi dutifully converted Jano's
ideas into mechanical drawings of the new P2 Alfa
Romeo. Had this car,
like the 1914 Grand Prix A.L.F.A. or the 1923 GPR, been unsuccessful,
we would not have to pause in our discussion of Alfa passenger cars. But
the P2 quickly dominated racing and continued to be competitive over a
period of six years, a remarkable achievement. The Type 35 Bugatti also
dates from 1924, but in virtually every instance where the Alfa and
Bugatti raced together, the Alfa won. As with Bugatti's practice of
transporting race-car practice to passenger cars, many of the P2's design
details, including the twin-cam head, were translated to Alfa passenger
cars. For its victories and seminal design, the P2 deserves special study.
The 1921 8-cylinder Fiats, from which Jano took his inspiration,
introduced a one-piece crankshaft with full roller-bearings and a
one-piece twin-cam cylinder head with valves set an included angle of
96 degrees. The wide valve angle allowed very-large diameter valve
heads for improved breathing. The 2-liter Fiat had a bore/stroke of 60/87
mm. In Jano's design, the bore/stroke ratio was revised to 61/85 mm
for a slightly lower piston speed. Both the Fiat and Alfa powerplants
maxed out at 5500 rpm, the Fiat giving 130 hp and the Alfa 140 hp.
The P2 engine was built up of three large castings: an iron cylinder head
in unit with the cylinders, cast without water passages; a shallow alloy
crankcase which split at the center-line of the main bearings and a deep,
lower crankcase half in alloy with large bearing supports. The
through-bolts which connected the two crankcase halves also secured the
cylinder block. The sump was little more than a ribbed plate, since
dry-sump forced lubrication was used. Thin sheets of metal were welded
around the cylinders to provide jackets for the coolant, a Mercedes
technique. The roller bearings gave superior load-bearing capabilities
with minimal lubrication needs and reduced drag from friction. The
mains and rod big-ends were split so they could be assembled to the
crankshaft, and semicircular cages were used to maintain individual roller
spacing.
While a Wittig-type positive-displacement supercharger had been tried on
the GPR Alfa, Jano elected to use a Rootes-type blower for the P2. The
unit was driven at 1.2 times crank speed for a boost of 10 psi. The
Rootes unit, which uses two figure-8 lobes, was the preferred
performance-enhancer for sporty cars in the 1930s. Looking ahead for
just a moment, the two lobes run with about 0.002 in. clearance, so there
is a boost pressure above which the blower begins to leak back into the
carburetor. For this reason, additional supercharging pressure can only be
gained by feeding one blower with another, the 2-stage technique
employed by the Type 159 Alfa of 1951 to develop
425 hp from only 1.5 liters.
On the P2, the supercharger lobes were displayed horizontally and an air
inlet was provided on both sides of the casting. Pressurized air was
delivered from beneath the supercharger to a finned tube which led along
the frame rails to a plenum on which two updraft carburetors were
mounted. Two two-into-four manifolds completed the intake plumbing.
The exhaust featured a graceful eight-into-one manifold which maintained
its elevation along the length of the car.
The chassis of the P2 was thoroughly classic: a ladder-type layout with
solid front and rear axles on semi-elliptic springs. The rear of the chassis
was curved to match the tapered bodywork and the rear springs were
splayed inward at the rear to match the curve of the chassis. The engine
mounted to the chassis solidly at three places and a torque-tube drive was
used, with a single universal joint located behind the 4-speed
transmission.
According to Fusi, only six of these cars were produced. One survives
today in the Alfa museum and another, in the Carlo Biscaretti museum,
is Varzi's P2 which was fitted in 1930 with a 1750 Gran Sport radiator
to improve cooling. Other modifications to Varzi's car included reversing
the relationship between the supercharger and carburetors and fitting a
6C1750 front axle, steering and brakes.
The P2 became the first world championship Alfa in 1925, earning Alfa
a garland around the badge which it displayed proudly until some
unlettered nitwit deleted it in the name of modernization.
KTUD Alfa Romeo main page!
Copyright March, 1996
This document or its parts can not be reproduced, quoted in any means.
You can create a link freely, but please let me know about it.
chapter 7
KTUD complete index