Technical characteristics

Chassis Platform: 1947 Chevrolet

Distance between axes: 2.94 meters

Front trail: 1.54 meters

Rear trail: 1.65 meters

Total height: 1.32 meters

Total width:

Clearance: 0.13 meters (for track)

Weight: without fuel or pilot 1.282 Kg.

Fuel tank (for route): 250 liters

Fuel tank (for circuit): 150 liters

Front suspension: original Chevrolet '47 with two shock absorbers per wheel

Rear suspension: Uniflex with two shock absorbers per wheel

Differential: Impala (core)

Case: 4-speed Corvette

Tires: 9.80 x 15 front-rear according to the circuit

 

Engine

They had to change the original characteristics of this engine of 250 cubic inches or 4.100 cc, to enter the regulation that required 4000 cc.

No. of cylinders: 6 in line

Diameter of cylinders: 97.2 mm

Stroke: 89.66 mm

Lubrication ducts: enlarged to 3 mm in diameter

Piston travel speed at 6000 RPM: 17.9 m / sec

Weight: 215 Kg

Cylinder cap: With a valve conduit for both intake (45 mm) and exhaust (40 mm). The combustion chamber tends to the hemispherical

Compression ratio: 10.5: 1

 

Crankshaft: Nitrided nodular cast iron with "shot peening" of the curvatures - Static and dynamically balanced together with the steering wheel.

Bearings: Connecting rod (50.8 mm) and bench (58.5 mm) are of the trimetal type. The admissible cross-sectional movement or movement in connecting rod and bed was 0.125 mm and the radial clearance for the connecting rod was 0.08 mm and those in the bed 0.10 mm.

Steering wheel: It is used to compete for the original engine but lightened 1.5 Kg - You can also use one made of a steel plate that is more resistant or opt for racing at the Autodromo by a duralumin with cast iron friction plate, because due to its low energy storage, a faster deceleration and acceleration of the motor is achieved.

Cranks: They are cast in chrome nickel molybdenum steel whose denomination is SAE 8640 with modified dimensions to a greater thickness.

Pistons: Duralumin sylicum with a large percentage of silicon, flat head with cut out the skirt. Three rings are used, two pressure (2mm) and one scratch elastic cast iron oil (4 mm) with chromed friction face and light between tips of 0.4 mm.

Piston bolts: They are made of rectified nickel-chrome steel. Its inner part is rectified in such a way that it has a conicity at its ends, that is to say, that in them, the wall is smaller than in its middle part. The bolt is floating on the rod and on the piston - its distribution of 85 mm and its diameter of 25.4 mm.

Distribution system: The rockers are made of cast steel and the flute where they pivot is made of rectified nickel-chrome steel and with a treatment of electric induction hardening. The flute supports are made of iron with bushings or can carry rollers. The valves are made of 48 mm diameter stainless steel for the intake and 40 for the 148 mm long exhaust. The guides are constructed of bronze with nickel or copper alloy 60 mm long. The Bellavigna used Montal cam trees made of nickel chrome steel, cemented and nitrided. The height was 12 mm. The camshaft bearings are the original white metal bearings.

 

The gears of the camshaft and crankshaft are replaced by high-strength steel ones. The punches are made of chrome nickel steel with hard chrome on the contact face with the cam. You get to use a pellet of vidia welded in the base. Roller pullers with a minimum of friction are replaced.

The rod lift valves are constructed in seamless drawn steel pipe with a length of 220 mm and a diameter of 9.5 mm. The valve springs are Iskederian, double and high speed recovery type. The working voltage of the set is with an open valve of 100 Kg and with a closed valve of 45 Kg.

Carburation: The intake system is composed of three double-mouth manifolds of an angled form of cast aluminum, on which are fixed the three double-body Weber carburetors, 48 ​​mm mouth and vertical shot. An adjustable pressure electric naphtha pump feeds the carburetors to a delivery pressure of 2.5 psi.

Lubrication: In some cases, the original pump is used, as also the original oil pump of the engine is used for the wet sump system.

Some opt for the use of attached external pumps.

On: It is done by a battery, coil, and distributor, which in the case of the Bellavigna, used the Mallory double platinum and Joseph instead worked on the original distributor.

Clutch: A special Schiffer brand American racing clutch of 266.7 mm diameter can be used. This clutch has a very low-pressure plate built in duralumin with the friction zone in steel. The diaphragm is made of steel and withstands a pressure of 1500 Kg.

 

THE DEBUT WITH THE "COLORADITA"

The debut of Juan Manuel Bordeu with the "Coloradita" occurs in Olavarría on March 3, 1963. That year participated in about fifteen competitions but its main locations were: 1st. in Junín - 1st. in Pehuajó - 6th. in the Grand Prize (wins the 4th Stage).

 

Reach in 1964 the title of Sub-champion, thanks to his very good performances. The victories of that season were Olavarría - Bahía Blanca - Rojas - Carlos Casares and the Argentine Grand Prix.

 

In 1965, runs the Two Oceans that joined Mar del Plata with Viña del Mar round trip. Bordeu marched first and in one of his stages suffers an accident: he skips the lid of the water tank that was placed behind the cockpit, the hot water burning on his back and also reaching his companion Alberto Lozano. Both had serious burns, mainly Bordeu, so it was out of competition for a few months. In 1966 it was his great year since I have reached the title of Champion in that category. Let's say he was the second T.C. that achieved that compliment with Chevrolet. Before, Fangio had done it in 1940 and 1941. The award was obtained on the basis of the following triumphs: Hughes - La Pampa - Autodromo of Bs. As. - Chacabuco - Double Return Mar del Plata Ayacucho - Carlos Casares - Olavarría - Junín - Mercedes

From 1967 another type of cars began to take over the careers of T.C. The modernization of the traditional "cupecitas" had been insinuating through the "Chevitú" built by José Froilán González for Jorge Cupeiro. The Torinos appear and everything began to change. Bordeu had a quite varied stage in what refers to their cars. I used one called "Monito" with an engine of Engineer Joseph, with which I won in the road course of Buenos Aires in 1968, the only race he did with that car. He also ran with a Baufer that in some races had a Chevrolet engine and in other Dodges. He also managed the "Garrafa" of Andrea Vianini in some races.

 

His return to victory was in 1971 with a Dodge Polara four doors. With that car, I have won three races that year: Olavarría, Bragado, and Zapala.

 

Then I had a Dodge coupe with which I could not win. It was his last race car since with him on December 17, 1972, in Zapala and when he went he had a mechanical problem that left him 8th... He never ran again.