The V8 Story
The United States car industry has been responsible for the design and production of vast numbers of V8 engines, which have proved powerful, dependable and cheap to manufacture without being particularly efficient. Their weight has often been excessive and their fuel consumption, by European standards (and judged in later years by ecological standards) little short of irresponsible.
In the 1950s various foreign imports into the USA were creating a new market, the 'compact'. It was then a matter of time before the US manufacturers produced a product to meet the needs of that market. The industry planned a new range of 'compacts'; smaller, lighter and more efficient than those being currently manufactured but still identifiable as pure American. An essential element in this scaling-down process was the powerplant and for the Buick division of General Motors this did not mean a four-cylinder engine. It would have to be powered by a V8.
The 1961 Buick Special represented Buicks reply to the intrusion by imported cars into their territory and the engine chosen to power it represented an equally radical departure from the established norm. Building an engine in aluminium was not a totally new concept, with aluminium engines way back in 1916. General Motors designed and built an aluminium V6 in 1955 with a single overhead camshaft on each cylinder head which led in 1958 to a more conventional 253 cu in (4145 cc) V8. In was from this 1958 experiment that the Buick-Oldsmobile production V8 was developed but it was the Buick engineers who designed it.
The all new aluminium Buick engine was a V8 of 215.5 cu in (3531 cc), with a bore of 3.5" and a stroke of 2.8"
Taken from this design was the Oldsmobile version, offered in the Oldsmobile F85 of the same year, but divisional differences within the GM empire meant their engineers were able to put their own stamp of individuality on the engine by making several changes. They designed their own cylinder heads which had a six- bolt pattern around each combustion chamber instead of the Buick's five-bolt, made changes to the valve gear and used different pistons.
Although both Buick and Oldsmobile used the same basic wedge-shaped combustion chamber, Buick opted for relatively small-volume chambers in the head and dished-top pistons, while Oldsmobile had a larger chamber in the cylinder head with a flat-top piston. The Buick heads also had the valves more offset from the centre of the chamber with the spark plug nearly in the centre, striving for a squish effect across the whole chamber. Compression ratio was 8.8:1 on the Buick and 8.75:1 on the Oldsmobile versions of the engine. Of greater significance was that the Oldsmobile had bigger ports and valves, although the power of both engines was the same.
Buick offered a two-barrel Rochester carburettor equipped version as standard, with 8.8:1 compression ratio, 155 bhp at 4600 rpm and 220 ft/Ib of torque at 2400 rpm. The four-barrel Rochester option with a 10.25:1 compression ratio boasted 185 bhp at 4800 rpm and 230 ft/Ib of torque at 2800 rpm.
The new engine was enthusiastically received and the prospect of a new generation of aluminium V8s had tremendous appeal. But for the buying public and General Motors, however, the reality of long-term customer ownership and mass-production were beginning to turn a little sour. The fickle American motorist was unfamiliar with the special needs of an aluminium engine, which had a particularly large capacity cooling system (around 4 gallons of coolant) requiring special antifreeze, this being long before the days of summer coolant antifreezes. By 1963 production of the engine was halted and from the design and tooling was developed a cast-iron V6 of 198 cu in (3244 cc) which replaced the aluminium V8 in the same range of GM compacts. For the Buick/Oldsmobile aluminium V8 of 1961 this was the end of the line after some three-quarters of a million units, or so General Motors thought.