Ferrari 500 TR (1956)

By the time that the 500 Testa Rossa was introduced in 1956, it had been preceded by a number of Ferrari four cylinder models, that had established the Ferrari four cylinder engine as a force to be reckoned with on the world stage. The story had started in 1952 with the 500 F2 Monoposto, in which Alberto Ascari won the Drivers’ World Championship, doing the same thing again in 1953 in the same type of car. This twin overhead camshaft four-cylinder engine was first used in a sports racing Ferrari in 1953, in a 625 TF model, then in different capacity forms in 500 Mondials, 750, 857 and 860 Monzas, which in turn led to the 500 Testa Rossa in 1956, the subject of this story, the 625 LM derivatives, and then ultimately the four-cylinder Ferrari engine’s final iteration in the 500 TRC derivative in 1957.

The “500” designation in the model title referred to the approximate swept volume of a single cylinder in cubic centimetres, thus the total cubic capacity was 2 litres, and the “TR” was for Testa Rossa, due to the red-painted cylinder head and camshaft covers. The model was essentially built as a customer car, primarily to compete for the 2-litre class race honours, whilst the company’s larger capacity V12 models vied for overall race wins. For this reason, the 500 TR was kept relatively simple. It featured the, by then, well-proven and robust four-cylinder power plant, with factory type number 131, designed by Aurelio Lampredi. As with all other Ferrari four-cylinder engines, it featured screw into the head cylinder liners, to obviate cylinder head gasket problems with, for the time, relatively high compression ratios.

The over square 2-litre power unit had a bore and stroke of 90mm x 78mm, providing an actual total displacement of 1984.86cc, with a compression ratio of 8.5:1. The crankshaft ran in five main bearings, with the twin overhead camshafts driven by a train of gears also driving the oil pumps, water pump, distributors and dynamo. It featured the narrow 58deg angle two valves per cylinder head as used on the original 500 F2 design in 1951, whereas series II 500 Mondial and 750 Monza models had used a wider 85deg cylinder head. The narrower angle head was deemed to provide greater combustion efficiency. The induction and ignition systems comprised of a pair of side draught Weber 40 DCOA 3 carburettors fed by a mechanical pump with a back-up electric pump, and twin spark plug per cylinder ignition via a pair of timing cover-mounted distributors. Lubrication was dry sump with gear-driven pressure and scavenge pumps, supplied from a 15 litre oil tank.

The claimed power output was 180bhp at 7000rpm, and this was fed from the engine via a twin-disc clutch, through a four-speed + reverse type 518/431 gearbox, incorporating Porsche synchromesh rings, and a propeller shaft to the rigid rear axle with a pawl pattern limited-slip differential, type number 518. A choice of four rear axle ratios were offered in the sales brochure, 7/34, 8/34, 8/32 and 9/34, which from the lowest to the highest gave claimed top speeds at 7000rpm of 119mph, 137mph, 145mph and 153mph. However, the “Scheda di Omologazione” (Homologation Schedule) lists seven optional axle ratios, which in that document range from 6/34 to 9/34.

The chassis was constructed to the regular Ferrari practice of the period, with a pair of large bore oval longitudinal steel tubes and substantial lateral cross bracing, with factory type reference number 518. It had a wheelbase of 2250mm, a front track of 1308mm, a rear track of 1250mm, and a 120 litre fuel tank, with the whole car having a dry weight around 680kgs. Suspension was independent at the front via coil springs and Houdaille lever type shock absorbers with an anti-roll bar, whilst the rear featured coil springs again with Houdaille lever-type shock absorbers and twin radius rods to the axle.

The braking system was hydraulic, with twin master cylinders and drum brakes all round, with a mechanically operated handbrake to the rear wheels, whilst the road wheels listed in the “Scheda di Omologazione” were either 5.00 x 15” or 5.00 x 16” wire wheels on Rudge hubs, with 5.50” wide tyres at the front and 6.00” at the rear, with an option of a metric size 165 x 400 front and rear. All cars in the series were fitted with an open spider aluminium body, which was designed and built by Scaglietti in Modena.