Page 10 - 1948 Talbot-Lago T26 Grand Sport -- Chassis 110101
P. 10
CHAPTER 1
ABOVE: The new 4.5-liter twin-cam 170-hp T26 Record engine with two Zénith-Stromberg carburetors as it was first shown at the 1946 Paris Salon. A lovely piece of classic engineering. (Peter Larsen)
TOP: The Marchetti-designed 4.5-liter T26 engine with its two cams high in the block, short pushrods, hemispherical combustion chambers and perfectly inclined valves. (Cars in Profile)
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an efficient 90 degrees to each other, operated via short pushrods and rockers on either side of the head, which made the engine look like a DOHC design to the casual observer. The single spark plug was in the center of the hemispherical combustion chamber. This system provided some of the advantages of a chain or gear-driven overhead cam configuration without incurring the development and production cost, which was always a problem for Talbot. The large valves gave good breathing, while the light reciprocating parts made the engine relatively free revving, although not able to achieve the dizzying heights of the V-12 Ferraris of just a few years later.
For the Record model, the twin-cam T26 engine was provided with a wet sump, an unsleeved block, a cylinder head cast in iron and aluminum valve covers. Equipped with two Zénith-Stromberg carburetors and a compression ratio of 7:1, power was 170 hp at 4,200 rpm, which made the big Talbot six one of the most powerful passenger car motors in the world at the time. The race cars received a sleeved aluminum block and aluminum cylinder head with magnesium valve covers, dry sump and oil cooler, higher compression, three carburetors and straight-cut exhausts. A twin ignition head with twin magnetos was introduced on Étancelin’s car for the GP at Reims in 1949. In early-1948 form, when the first single ignition T26 Cs were introduced, power was in the region of 240 hp at 4,700 rpm on an 8:1 compression ratio. Top speed was around 250 km/h.
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