BBC 348

The first iteration of the "W" engine was the 1958 "Turbo-Thrust" 348-cubic-inch (5.7 L) originally intended for use in Chevrolet trucks, but also introduced in the larger, heavier 1958 passenger car line. Bore was 4.125 in (104.8 mm) and stroke was 3.25 in (83 mm), resulting in a substantially oversquaredesign. This engine was superseded by the 409 as Chevrolet's top performing engine in 1961 and went out of production for cars at the end of that year. It was produced through 1964 for use in large Chevrolet trucks. With a four-barrel carburetor, the base Turbo-Thrust produced 250 hp (190 kW). A special "Tri-Power" triple-two-barrel version, called the "Super Turbo-Thrust" produced 280 hp (210 kW). A "Special Turbo-Thrust" upped the output to 305 hp (227 kW) with a single large four-barrel. Mechanical lifters and the three two-barrel carburetors brought the "Special Super Turbo-Thrust" up to 315 hp (235 kW). For 1959 and 1960, high-output versions of the top two engines were produced with 320 hp (240 kW) and 335 hp (250 kW) respectively. In 1961, power was again increased to 340 hp (250 kW) for the single four-barrel model, and 350 hp (260 kW) when equipped with three two-barrels.