Buick V8 engine
The Buick V8 is a family of V8 engines produced by the Buick division of General Motors between 1953 and 1981. All were 90° water-cooled V8 OHV naturally aspirated engines.
Evolution
The Buick V8 family can be divided into three groupings: "Nailheads", produced between 1953 and 1966, which came in two generations using different blocks in displacements from, and are known for their unique valve design and head configuration; "small blocks" produced from 1961 to 1982 in displacements from ; and "big blocks" produced from 1967 to 1976 in displacements from.The use of "small-block" and "big-block" terminology refers to the respective engine block's bore spacing, external dimensions, and weight, not internal engine displacement.
The "Nailhead" nickname derives from the unusually long, small valves of the original Buick V8, a function in part of the unusual horizontal positioning of the engine's heads.
Even though they are not generally held to be, by some important empirical measures, including a deck height that allowed displacement to grow to, the Buick "Nailhead" engines can be regarded as "big block" - a term that did not exist in that usage until exceptionally large displacement V8s with correspondingly large blocks began to appear and be distinguished from their more moderate-sized predecessors. The term "small-block" is a retronym, developed to distinguish engines with small and medium blocks from the very large block engines being introduced in response to increasing automobile size and the "horsepower wars" of the 1960s.
Both the Nailheads and the mid 1960s-on "big-block" engines shared a bore spacing. The Buick "small-block", which predated the "big-block", had its own block and bore spacing. Both "big-" and "small-block" engines were clean sheet designs.
Some Buick V8s, such as the 350, 400, and 455, have the same displacements as V8s of other GM divisions, but they are entirely different designs. Buick Nailhead V8s can be distinguished by the top surfaces of their valve covers being horizontal. Later Buick small and big block V8s have a front-mounted distributor tilted to the drivers side, but siamesed center exhaust ports.
Nailhead
Buick produced two generations of "Nailhead" engine, serially between 1953 and 1966. The first spanned 1953-1956, in two displacements: the original from 1953 to 1956, and a de-bored "junior" version only in 1954 and 1955. The second spanned 1957-1966, with an original displacement produced 1957-1961, a from 1959-1966, and a final from 1963 to 1966. All second generation engines used the same block, bore spacing, and different combinations of bore and stroke. All Nailheads had cast iron blocks and heads. Both generation's vertical valve arrangement resulted in unusually compact V8s of their displacement.The two engines shared a similar valve architecture but were different designs with different blocks. Among the changes in the second generation were larger, less-restrictive valves and ports, a better flowing manifold, thinner castings for both block and heads, new 1.6:1 rocker arms, increasing valve lift, more radical camshafts with increased duration.
First-generation
Buick's first generation V8 was offered from 1953 through 1956; it replaced the Buick straight-eight. While officially called the "Fireball V8" by Buick, it became known by enthusiasts as the "Nailhead" for the unusual vertical alignment of its small-sized valvesDuring this era, Buick ranked smoothness above most other marketing objectives, and the Dynaflow transmission's non-shifting design was demonstrably smoother than the other rough shifting automatics then available. With the Dynaflow, a high torque engine was needed to provide adequate acceleration, so that's what the Nailhead was designed to deliver.
Both the intake and exhaust valves were on the intake manifold side of a "pent-roof combustion chamber". To offset restrictive port diameters and the smaller-sized valves , the Nailhead V8s used a camshaft with greater lift and duration. The small-diameter intake runners allowed these engines to develop high torque, with many exceeding 1 ft-lb/cu in.
First-generation Nailheads were painted "Late" Buick Green.
264
The followed the 322 as a junior V8 produced in 1954 and 1955 as a direct replacement for the smaller Buick 263 straight-eight, and was the only engine available in Buick's economy "Special" series vehicles. It was the smallest displacement Nailhead, sharing stroke and deck height with the 322, but having a smaller bore.322
The larger was the original Nailhead, used by Buick from 1953 through 1956 in the Roadmaster, Super, and Century models, and the Special in 1956. It has a bore and stroke of.The 322 was also used in the 1956 through 1957 10,000-Series conventional-cab Chevrolet heavy duty trucks labeled as the Loadmaster.
Second-generation
Buick's second variation of the "Nailhead" was produced from 1957–1966. The "Fireball" name was dropped after 1957, but the 364 was very briefly called the "B-12000", referring to the 12,000 pounds of force generated by each piston. Second generation Nailheads were painted "Late" Buick Green, with the exception of those installed in the 1963 Riviera, which were silver, and the 1966 Riviera, which were red.364
Buick, like most of its competitors, continued to expand its V8 engine to larger displacements. The was introduced in 1957 and produced through 1961, with a bore and stroke. All other models got the four-barrel engine except for the lower level Special series, which received a two-barrel carburetor version.401 (400)
The 364 was enlarged to and produced from 1959 to 1966. Both bore and stroke were enlarged, to respectively. Originally sold as a 401, it was later redesignated "400" to meet a 1960s Division-wide GM directive mandating a maximum allowable displacements in mid-size cars.The 401/400 became Buick's original muscle car powerplant, used in the company's Skylark Gran Sport, Buick Sport Wagon and Buick Wildcat models, among others. The engine was variously designated the Wildcat 375, Wildcat 410, and Wildcat 445 - with the numbers corresponding with the torque produced by each version. The Wildcat 410 was the two-barrel carbureted engine, standard on the 1962-1963 LeSabre. The Wildcat 375 was a no-cost economy option for the 1962-1963 LeSabre that used a lower compression ratio to run on mid-octane rather than premium fuel. The various Wildcat engines had decals on their air cleaners indicating their version; however, a later four-barrel edition of the 1966-1967 small-block [|Buick 340] V8 was also labeled Wildcat 375 on its air cleaner.
The single four-barrel Wildcat 445 was the standard engine in the Invicta, 1959-1966 Electra, 1962–1966 Buick Wildcat, 1963 Riviera, and 1965 Riviera.
425
The, the largest-displacement Nailhead, was produced from 1963 to 1966. Its bore and stroke measure. It began as an exclusive option on the 1963 Riviera, and was later available on the Wildcat and Electra models. It was standard on the 1964 and 1966 Rivieras.The basic 425, called the Wildcat 465 for the lb-ft of torque it developed, came with a single four-barrel carburetor. The Super Wildcat featured two four-barrel carburetors and matching intake manifold, was available on the 1964 Riviera as a factory option, 1964 Electras, 1965 Riviera Gran Sport, and 1966 Wildcat GS,
Coded "MW", these Regular Production Option -code Y48 parts were delivered in the car's trunk for dealer installation. Toward the end of the 1966 model year, around May 1966, Buick offered the Super Wildcat 465 with factory-installed
dual four-barrel Carter AFB carburetors as an "MZ" option. Only 179 of the 1966 Riviera GS models were built with the MZ package.
Mounted on a trolley, Buick 425s were also used as starter motors for the SR-71 Blackbird supersonic jet.
Small-block
Buick introduced a all-aluminum "small block" V8 in 1961, an industry first. Produced in three other displacements, it had a cylinder bore spacing, and became the basis of a highly successful cast iron Buick "Fireball" V6. Design features include an external oil pump, a forward-mounted distributor, and an integrated aluminum timing cover incorporating the oil pump and leaving it and the oil filter exposed to oncoming air for added cooling.After three years of persistent cylinder liner issues in the aluminum blocks, cheaper new thin-wall iron casting techniques, resulted in a shift to an iron block in 1964.
Buick small-block 300's were painted "Late" Buick Green. 1966 340 and subsequent engines were painted red from 1967-1974, medium metallic blue from 1975-1977, and light blue from 1978-1982.
215
GM experimented with aluminum engines starting in the early 1950s, when Aluminum Company of America was pushing all automakers to use more aluminum. An early-development was a supercharged V8 used in the 1951 Le Sabre concept car, and the 1953 Buick Roadmaster concept car. That design is unrelated to the 215 cu in all-aluminum V8 introduced by Buick in 1961.GM designated Buick as engine design leader, and work on a production small displacement aluminum V8 commenced in 1956. Originally intended to displace, Buick increased this to to be more compatible with the new Y-body cars on the drawing board, introduced for 1961 as the Skylark.
Known as the Buick Fireball, the all-aluminum 215 had a strongly oversquare bore and stroke of, for an actual displacement of. With a Rochester 2GC two-barrel carburetor and 8.8:1 compression ratio power output was at 4400 rpm and of torque at 2,400 rpm. Weighing only, it was the world's lightest mass-production V8. Measuring long, wide, and high, it became standard equipment in the 1961 Buick Special.
Power was raised soon after introduction to at 4,600 rpm. A Buick Special Skylark version was introduced mid-year, which had 10.0:1 compression and a four-barrel carburetor, raising output to at 4,800 rpm and at 2,800 rpm.
For 1962, the two-barrel engine was unchanged, while the four-barrel engine's compression ratio was increased to 10.25:1 and output to at 4,800 rpm and at 3,000 rpm. For 1963, the four-barrel was bumped to 11.0:1 compression and an even at 5,000 rpm and at 3,200 rpm, /cu in. The higher output "Power Pack" was equipped with higher lift camshaft.0.518" intake/ 0.523" exhaust with increased duration 305/310 and required 99 research octane fuel.