chapter 1
This page is dedicated to the memory of Pat Braden who died on August 25, 2002.
Chapter 2
A French Interlude
In the beginning installment of this history, I observed that much of the
Italian automobile industry owed its origins to France, and that even
A.L.F.A. was a follow-on to a French enterprise. Its not surprising that
the same French dominance ocurred in automobile racing: the history of
auto racing can be seen as a continuing attempt by the French to control
politically what they could not control technologically. The first serial
event was the 1900 Gordon Bennett cup, a prize donated by the owner
of the New York Herald newspaper and held in conjunction with the
Auto Club of France (ACF). It was from the Gordon Bennett series that
grand prix racing evolved. The first grands prix were two-day events run
on what became known as the Sarthe circuit of LeMans.
While Mors, Panhard, Peugeot and Renault were important French
marques during this era, Fiat and Itala had become competitive for Italy
and Mercedes maintained Germany's presence. The displacements of
racing cars rapidly escalated to heroic proportions and displacements over
10 liters were common. These monsters clearly had little to do with
production cars, and there was some suspicion among manufacturers that
racing did nothing to enhance sales. Further, the French were souring on
grand prix racing, being unable to field a winning team: Renault took the
first grand prize in 1906, but Fiat won in 1907 and Mercedes won in
1908. As a result, the manufacturers agreed to withdraw from racing
even as plans for the 1909 grand prix were underway.
That is, A.L.F.A. entered production at a time when the sporting world
was re-focusing its attention on regular production vehicles. It couldn't
have been a more propitious time for a company committed to the
production of sporting passenger cars with small, high-efficiency engines.
In the absence of the monstrous grand prix cars, Coupe de l'Auto races
for smaller-displacement production cars became popular. Once again the
French were able to distinguish themselves, as the Lion-Peugeot proved
very competitive. Its primary competition was the Hispano Suiza
designed by Marc Birkigt and the Sunbeam designed by Lawrence
Pomeroy. The success of the Coupe de l'Auto races finally brought the
ACF back into grand prix racing: for 1912, it decided to run an event in
conjunction with the smaller Coupe races. The only restriction on the
grand prix cars was that they could not have a body wider than 1.7
meters.
For the 1912 event, Peugeot decided to field a new grand prix car of 7.6
liters designed by Ernest Henry, who had collaborated with Marc Birkigt
in the development of an Hispano Suiza for King Alfonso XIII. The
4-cylinder Hispano engine featured twin overhead camshafts, hemispheric
combustion chambers and four valves per cylinder, but no sooner was it
designed than Henry and Zucarelli, the chief tester for Hispano Suiza,
sold the design to Peugeot. Birkigt sued and won for the theft, but
Peugeot still had the design.
Why am I telling you all this? Because A.L.F.A. decided to enter grand
prix racing in 1914, four years after its founding and two years after the
appearance of the Peugeot. Merosi did little more than copy Birkigt's
design, as interpreted by Henry. Indeed, when, in 1923, he was once
again asked to create a grand prix engine, he did little more than update
his 1914 design. Given Alfa's future success in the grands prix, a closer
examination of this 1914 car and its Peugeot predecessor is appropriate.
By 1912, designers were beginning to master the problems associated
with getting more power out of an engine. The era of surface carburetors,
hot-tube ignition, automatic inlet valves and monstrous displacements had
all but passed. Designers had found the upper limits of an engine's size:
beyond a certain stroke, piston speed became destructively high; beyond
a certain bore, there was no hope of burning all the fuel in the charge
before the exhaust valve opened.
The most obvious direction for improvements was to increase the speed
of the engine. The reason for this is that the formula for horsepower
includes a value for time: the faster an engine works, the more
horsepower it can develop, at least, theoretically. It was not long before
the engineers ran into the limitations of theory. Improvements in both
metallurgy and petrochemicals allowed the higher engine speeds because
metals were stronger, fuels could be burned in a more controlled manner
and lubricants protected metals better. At higher engine speeds, however,
gas dynamics became the limiting factor: you couldn't get the charge
in and out of the engine fast enough.
The original gas path through an engine was a virtual afterthought. A
half-speed camshaft driven by a gear off the crankshaft suggested the
T-head design, in which the intake and exhaust valves were operated
directly by individual camshafts and seated themselves on the upper
surface of the block. The resulting gas path was sinuous, and every turn
offered resistance to gas flow. At slow speeds, the resistance was
negligible, but at higher speeds, the forces had to be accommodated.
Clearly, the most efficient gas path through an engine is a straight line.
It was this realization, no doubt, which prompted Birkigt to want to place
the valves at an angle above the combustion chamber so that the gas flow
might follow a nearly straight line. There were two immediate benefits
of this approach: the resulting combustion chamber was almost an
hemisphere and the spark plug could be placed in the center of the bore,
both features contributing to even combustion. Birkigt also understood
that two smaller valve heads offered lower reciprocating mass and a
larger area around their circumference than a single large valve.
Now, Fiat had already produced a racing engine in 1909 which had a
single overhead camshaft which operated parallel valves through roller
tappets. But the inertia of the tappets required heavier valve springs and
the layout did not permit an hemispheric chamber. It was clear to Birkigt,
at least, that the highest speed engines would have two camshafts which
operated the valves at an included angle of some 90 degrees.
That is a concise summary of the advantages of what has become the
traditional high-performance engine cross-section: twin overhead
camshafts operating valves in an hemispheric combustion chamber. And,
it has been that exact configuration which, between 1925 and the
introduction of the V6 engine in 1981, has characterized Alfa.
In both the Peugeot and A.L.F.A. design, the entire valve assembly, seat,
springs and all, was screwed into the monobloc cylinders. In both cases
also, the cams ran in cam boxes above the exposed valve stems and
springs to assure adequate valve cooling. Unlike the Peugeot, the GP
Alfa had two spark plugs per cylinder for more positive fuel burning.
The engine in the GP Peugeot was isolated from chassis stresses by
being carried in a subframe: in contrast, Merosi bolted his engine directly
to the frame. The Peugeot used a double-jointed driveshaft which
absorbed none of the rotational forces of the rear axle: in contrast, I
believe the Merosi car used a torque tube. In the Alfa, then, the
propelling motion of the driveline was delivered to the chassis centrally,
at the cardan joint just behind the transmission, and not at the forward
spring shackles as on the Peugeot.
Though revolutionary in theory, the Peugeot actually performed only
slightly better than its contemporaries. The real advantages of Birkigt's
design would have to await the higher engine speeds allowed by even
better metals and fuels. However, the advantage was great enough to win
both the 1912 Grand Prix and the 1913 Indianapolis 500, the first
European car to win that race. Only one example of the Alfa Grand Prix
car was built. It did not race before the Great War, but appeared
occasionally at post-war races, its last appearance being at the 1921
Grand Prix for Gentlemen where it was driven by Campari.
KTUD Alfa Romeo main page!
Copyright March, 1996
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chapter 3
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