Buick V8 engine

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 (parallel to the ground). Later Buick small and big block V8s have a front-mounted distributor tilted to the drivers side (like Cadillacs), but siamesed center exhaust ports (unlike Cadillacs). ==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. by Buick, it became known by enthusiasts as the "Nailhead" for the unusual vertical alignment of its small-sized valves (Originally it was known to hot-rodders as the "nail valve", because the engine's small heads contained valves with long stems, which made them look like nails.) 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. ==Small-block==

Buick introduced a "small block" V8 in 1961, an industry-first all-aluminum design. It included an aluminum timing cover that integrated a forward-mounted distributor and external oil pump, which exposed the pump and oil filter to incoming air for added cooling. It had a cylinder bore spacing, and used a new bellhousing pattern. After three years of persistent cylinder liner issues in the aluminum blocks, cheaper new thin-wall iron casting techniques led to a change to an iron casting in 1964. Along with this change was a swtich to the new standardized BOP bellhousing pattern. The iron casting was used for three displacements (300, 340, and 350 cu in). 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. 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 (2 Jet) 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. Pontiac usage Pontiac used the Buick version of the 215 in its Y-body cars, the Tempest and LeMans. At that time the engine was closely associated with the Buick brand, and Pontiac sold few cars with it, using it only in 1961 and 1962. Oldsmobile version Although sharing basic architecture with the Buick, Oldsmobile developed its own all-aluminum 215, the "Rockette V8", to install in its F-85 Cutlass Y-body. Its angled valve covers were designed by Oldsmobile engineers to look like a traditional Olds V8. Olds also released a turbocharged version, the Turbo-Rocket, in its 1962–63 Oldsmobile Jetfire. Together with Chevrolet's turbocharged 1962 Corvair Spyder, these were the first turbochargers ever offered in passenger cars. Produced on a separate assembly line, the Olds 215 was somewhat heavier at . Oldsmobile added a sixth head bolt on the intake manifold side in an effort to alleviate a head-warping problem on high-compression versions. This meant that the five-bolt Buick heads would fit on Oldsmobile blocks, but not vice versa. The Oldsmobile used wedge-shaped/quench combustion chambers/pistons that allowed larger valves, while the Buick had a 37-cc wedge combustion chamber and used "dished head" pistons. Altering the compression ratio on the Oldsmobile 215 required changing the heads, but on a Buick 215, only the pistons were changed, which was less expensive and simpler. Discontinuation Casting-sealing technology was not advanced enough at that time, and hidden porosity problems caused serious oil leaks, producing an abnormally high scrap ratio. and TVR. The engine remains well-supported by enthusiast clubs, specialist parts suppliers, and by shops that specialize in conversions and tuning. 300 In 1964, Buick replaced the 215 with an iron-block engine of very similar architecture. The new "small block" engine had a bore of and a stroke of for a displacement of . It retained the aluminum cylinder heads, intake manifold, and accessories of the 215 for a dry weight of . The 300 was offered in two-barrel form, with 9.0:1 compression, making at 4600 rpm and at 2400 rpm, and four-barrel form, with 11.0:1 compression, making at 4800 rpm and at 3000 rpm. For 1966, the 300 switched to cast-iron heads, raising dry weight to , still quite light for a V8 engine of its era. The four-barrel option was cancelled for 1966, and the 300 was replaced entirely by the 350 in 1968. In 1964, while nearly all Buick engines were painted "Buick Late Green", the 300 V8s were painted silver instead. In 1966 Buick engines switched to "Buick Late Red", but until 1967 at least, the 300 V8 (and the 225) were still painted Buick Late Green. The Apollo 5000 GT sports car, (also sold as the Vetta Ventura) used this engine. 340 In 1966, the 300's stroke was increased to in a raised block to create the 340, displacing , as a replacement for the four-barrel-carbureted 300. The taller deck (raised by compared to the 215/300's) meant the intake manifold was of a new design to bolt to the otherwise interchangeable cylinder heads. It was offered with two- or four-barrel carburetion, the two-barrel with a 9.0:1 compression rated at at 4,000 rpm and at 2,400 rpm, and the four barrel with 10.25:1 compression, rated at at 4,000 rpm and at 2,800 rpm. It was only produced through 1967, being replaced by the new small block in 1968. 350 Buick adopted the popular 350 size in 1968 for their final family of V8 engines, which was produced through 1980. Although it shared the displacement of the other GM small blocks, including the contemporary Chevrolet 350, Oldsmobile 350, and Pontiac 350, the Buick blocks were of a substantially different proprietary company design. The Buick 350 featured the same bore as the version of the Buick 90° V6 and retained the stroke of the previous V8. The exact displacement is . The major differences of the 350 in comparison to other GM V8s are Buick's "deep-skirt" engine block construction, the use of cast iron with increased nickel content, under-square cylinder bore sizing, crankshaft main journals, and connecting rods. Of all the GM "350s", the Buick has the longest piston stroke, essentially the same as the Buick big-blocks, which have the shortest stroke of the GM big-blocks. The engine garnered a reputation as rugged and durable, and some of its design characteristics are found in other Buick-designed GM engines, such as the V6 and its 3800 descendants. The 350 was used by Kaiser-Jeep and AMC Jeep in the Jeep Gladiator and Wagoneer models from 1968–71; in these applications, the engine was billed as the Dauntless V8. • 1968-1972 Buick Skylark • 1968-1972 Buick Sport Wagon • 1968-1971 Jeep Gladiator • 1971-1973 Buick Centurion • 1971-1980 Buick Electra • 1971-1980 Buick LeSabre • 1973-1975 Buick Apollo • 1973-1977 Buick Century • 1973-1977 Buick Regal • 1975 Pontiac Ventura • 1975-1979 Buick Skylark • 1977-1980 Buick Estate • 1977-1978 Buick Riviera ==Big-block==

Buick introduced its "big block" V8 in 1967 to replace the largest displacement Nailheads, which had grown to . It retained the cylinder bore spacing and was produced in three displacements: 400, 430, and 455 cubic inches. Production continued through 1976. 400 The big-block V8 was produced from 1967-1969. This engine has a bore and a stroke of . It was the only large V8 engine available for the intermediate-sized GM A platform Buicks due to GM's 400 cubic inch displacement limit on mid-size cars in effect through 1970. Most parts except the pistons interchange with the 430 and 455. This 400 engine had the distributor towards the front of the engine, as opposed to the 401/400 nailhead, which had its near the firewall. 430 The was only produced from 1967 until 1969. This engine had a bore and a stroke of , for an actual displacement of . The 430 four-barrel engine was rated at and of torque. This engine was used in large B-, C- and E-body Buicks. Most parts except the pistons interchange with the 400 and 455. Applications: • 1967-1969 Buick Electra • 1967-1969 Buick Riviera • 1967-1969 Buick Wildcat 455 The 400-based 455 was produced from 1970–1976, with a bore and stroke of for an overall displacement of . Most parts (except pistons and heads) interchange between the 400 and the 430. The base model was rated at , while the 455 Stage 1 equipped with a single 4-barrel Rochester Quadrajet carburetor was rated at at 4600 rpm. advance in production technology, it weighs significantly less than other engines of comparable size (for example, less than a Chevrolet 454 • 1970-1976 Buick Estate • 1970-1976 Buick LeSabre • 1970-1972 Buick Skylark • 1970 Buick Wildcat • 1971-1973 Buick Centurion • 1973-1974 Buick Century • 1973-1974 Buick Gran Sport • 1973-1974 Buick Regal ==Other GM V8s used in Buicks==

In the mid-1970s, Buick's 455 big block became unable to meet fuel economy/emission requirements and was phased out, with the Buick 350 remaining as a factory option until 1980. In their place a variety of other GM divisions' V8s were offered, both as standard equipment and factory options. These included: Oldsmobile 260 The Oldsmobile V8 engine#260| was an Oldsmobile V8 engine shared with Buick: • 1975–1977 Buick Skylark Pontiac 301 The Pontiac V8 engine#301| was a Pontiac V8 engine shared with Buick. Chevrolet 305 The Chevrolet Small-Block engine#305| was a Chevrolet V8 engine shared with Buick: • 1978–1987 Buick Regal • 1975–1979 Buick Skylark Oldsmobile 307 The Oldsmobile V8 engine#307| was an Oldsmobile V8 engine shared with Buick: • 1980–1985 Buick Lesabre • 1980–1984 Buick Electra • 1980–1985 Buick Riviera • 1980–1990 Buick Estate Wagon • 1986–1987 Buick Regal Oldsmobile 403 The Oldsmobile V8 engine#403| was an Oldsmobile V8 engine shared with Buick: • 1977 Buick Century estate • 1977–1979 Buick Riviera • 1977–1979 Buick Electra • 1977–1979 Buick Estate Wagon • 1977–1979 Buick LeSabre ==See also==