Massimo Grandi brings us into the fascinating history of Giuseppe Furmanik’s Maserati Siluro 4CM Carenato, a record-breaking car in automotive engineering. The article traces the origins of the Maserati 4CM, highlighting its development by the Maserati brothers and its transformation into a speed record challenger. Furmanik's innovative work in aerodynamics and engineering is explored, showcasing how his modifications led to multiple world records. The Maserati Siluro 4CM Carenato exemplifies the blend of scientific principles and aesthetic design in early 20th-century racing. Words and Drawings Massimo Grandi
The history of Giuseppe Furmanik's record-breaking Maserati 4cm is profoundly intertwined with the birth of the prestigious Italian brand Maserati.
In the early 1920s, the brothers Alfiero and Ernesto Maserati were well-known and esteemed, both as drivers and designers, and in 1922 the prestigious firm Diatto called them to direct its racing team. In 1923, the engineer Giuseppe Coda, Diatto’s director and designer, built 2 experimental 4-litre straight-8 engines, coupling standard Diatto Type 20 blocks. Between 1924 and 1925, under Coda's guide, Alfieri Maserati designed and built a new engine, with a smaller displacement of 1995 cc. This was the first 8C Diatto built by Maserati, an aluminium twin-shaft straight cylinder block with 2 Memini carburettors and a Roots-type compressor. This engine was used in the now-legendary Diatto 8C Grand Prix with compressor, 160 HP and bodywork by Schieppati that saw the light in June 1925.
When Diatto withdrew from racing in 1926, ten Type 30 sport chassis, equipped with gears and other mechanical parts, were purchased by the gentleman-driver Marquis Diego De Sterlich who, a huge fan, wanted to give them to the Maserati brothers, convincing them - also with financial help - to set up their own car racing firm, and thus in 1926 Alfieri and Ernesto Maserati set up the historical “Trident” company.
The first racing car was named “Tipo 26”, after the year of manufacture. It was driven by a straight-8 1500 cc engine, meeting the new international regulation, and was supercharged by a compressor that produced 120 HP at 5,300 rpm. It was the very first actual Maserati.
On 25 April, 1926, the Tipo 26 made its début in the Targa Florio. It was red, the Italian national racing colour, and wore number 5.
Alfieri, assisted by the mechanic Guerino Bertocchi, won its class and eighth place overall, even ahead of two Bugattis. Three were made during the first year of production, with chassis numbers 11, 12 and 13. Production of the Tipo 26 continued until 1932, with constant technical improvements and different set-ups.
Between the late 1920s and early 30s, racing cars with small engines - the so-called “Voiturette” class, gained popularity in the racing world, especially among private drivers. And so, in 1929 Maserati developed a 1100 cc version of the Tipo 26.
Yet compared to the French Salmsone and Amilcar, the car was overweight, so after producing four cars, the Tipo 26C or 8C 1100 was abandoned and Alfieri Maserati started from scratch. One of the main reasons for the excessive weight of the Tipo 26C was the rather large and heavy straight-8 engine. It was replaced with the first 4-cylinder engine, much better suited to the small car. With two overhead camshafts and a Roots-type compressor, the new 1088 cc "quattro" delivered 90 HP.
And so, in 1932, the small, single-seater Maserati 4CM was born.
The 4CM was produced until 1938, in several series, with engine capacities respectively of 1100, 1500, 2000 and 2500 cc.
Giuseppe Furmanik, a key engineer in the Italian racing world and famous driver from Rome, bought a Maserati 4CM 1100 cc in August 1933, #1120. Intending to join the world speed record challenge, Furmanik immediately began to develop the mechanics, and progressively also the body.
In the mid-30s, aerodynamics was in its very early stages, and Giuseppe Furmanik's Maserati 4 CM was used as a laboratory car for the new experimental aerodynamic studies.
The car developed rapidly as the studies progressed.
In 1934, on the Firenze-Mare motorway, Giuseppe Furmanik set a new world flying kilometre record in the 1100cc class, reaching a speed of 222.634 kilometres per hour (over 138 mph), beating the previous record of 207.527 km/h held by MG.
The car had not only evolved in its mechanics but above all in terms of aerodynamics.
The front had been completely re-designed, reducing the front air intake to an oval opening in the profile of the old grille, now fully integrated into the body. The chassis and front leaf-springs were also hidden inside a shaped fairing.
Two years later in Pescara, the car won the standing kilometre record in 27’’38/100 with an average speed of 131.483 and the standing mile in 39’’57/100 average km. 146.415.
Twenty days later, on the Firenze-Mare it beat its own records, with the flying start over a kilometre in 14’’42/100 average 249.653 and over a mile in 27’’28/100 average 212.376.
It also beat the records in class D with standing start over a kilometre in 23’’865/1.000 average 150.849 and over a mile in 35’’00 at an average speed of km. 165.532.
In 1937 Furmanik went even further in his aerodynamic experiments, and at the Viotti Coachbuilders in Turin, designed by Mario Revelli from Beaumont and developed at the Experimental aeronautic research centre in Guidonia, came the Maserati 4CM 1500 LSR (Land Speed Record) more commonly known as the “Maserati Siluro 4CM Carenato".
The engine was a Maserati 1495.7 cc (1500). The greater displacement was obtained by changing both the bore and the stroke. The larger engine also demanded a larger compressor and a Weber carburettor. The 4CM 1500 engine delivered 130 or 150 CV depending on the use of the fixed head.
The supercharged engine further developed by Furmanik, with a 100 mm stroke and 69 mm bore, with Burgo pistons, reached even 200 CV at 7000 rpm. The original bodywork of the 4 CM was then completely changed, with a practically complete fairing, aiming to create increasingly fluid and continuous lines. A huge stabiliser fin sat at the back.
It was designed by Mario Revelli from Beaumont, with the bodywork by Carrozzeria Viotti. The passenger compartment was closed by a dome that made the car look more like a torpedo - siluro in Italian - that gave it the name "Maserati Siluro 4CM Carenato". Even the front brakes were eliminated to lighten the car as much as possible in order to give it more speed.
The underlying arrangement of this aerodynamic model was the classic one specified in Jaray’s 1920s patent, with a central body with a longitudinal winged section with a drop-shaped roof.
A similar solution had already been adopted for a 1934 Maserati 4CM 1500, based on the design by the German designer Reinhard von Koenig-Fachsenfeld with bodywork by Vetter for the Swiss driver Hans Ruesch.
With his Maserati Siluro 4CM Carenato, on 2 and 3 June 1937, on the Firenze-Mare motorway, he beat the class record for the standing start kilometre in 24’’935/1.000 average 144.3, and in the standing start mile in 34’’325/1000 average 168.8 and the flying kilometre in 15’’9/100 with an average of 238.6 km/h.
Although he won these two major international records, Furmanik didn’t manage to beat Frank Lockhart’s record on the flying mile.
This was a really exceptional record: Lockhart was not only a skilled driver but also a great engineer and manufacturer, who had developed his Miller Perfect Circle 8-cylinder 1.500 cc supercharged engine that delivered 240 HP at 7,500 rpm. In 1927, in California, he covered the flying mile in 21.95 seconds, at a speed of 263.946 Km/hour.
Furmanik couldn’t get more than 6400 rpm from his engine, while at full power it was 7000 rpm. This is enough to explain why the attempt to beat the previous record failed. But his attempt did trigger a discussion on aerodynamic efficiency, and so on Furmanik’s Maserati CX and its exposed front wheels with only a rear fairing.
As we know, exposed wheels offer higher aerodynamic resistance, and so a full fairing drastically lowers the drag coefficient. Right from the start, they imagined that perhaps with a full fairing, seeing as the Maserati weighed less than Lockhart's Miller at 800 kg, they would have been able to reach higher speeds. In fact, in the original rendering the fairing covered all four wheels, also using disc hubs.
This solution was similar to the one adopted by Lockhart for his wonderful 1928 Stutz Black Hawk Special. We do not know why Furmanik opted for this choice, from the period photos of the record attempt on the Firenze-Mare motorway, the car appeared even without any fairing on the wheels.
Also in an original Luce film of the event, the car appeared initially with the fairings on the rear wheels, and then racing without them.
Whatever Furmanik’s choice of racing with or without the fairings, the original design of this car fitted out by Viotti remains very interesting. It represents an excellent combination of the scientific application of the principles of aerodynamics and aesthetics, seeking an elegantly harmonious model even for a car intended simply to beat a speed record.
With its records and its design, Furmanik’s Maserati 4CM undoubtedly wrote a chapter in the history of car racing and car design.
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