| Buick V8 engines | |
| Manufacturer: | Buick (General Motors) |
| Aka: | Fireball V8 (nickname) Nailhead (1953–1966) |
| Production: | – Buick City (engine block and heads) Saginaw Metal Casting Operations |
| Predecessor: | Buick straight-eight |
| Configuration: | 90º V8 |
| Displacement: | NaN1NaN1 |
| Bore: | 3.5- |
| Stroke: | 2.8- |
| Block: | Cast iron, Aluminum |
| Head: | Cast iron, Aluminum |
| Valvetrain: | OHV 2 valves x cyl. |
| Compression: | 8.8:1 - 11.0:1 |
| Turbocharger: | In 1962-63 Oldsmobile Cutlass only |
| Fuelsystem: | Carter AFB or Rochester carburetors |
| Fueltype: | Gasoline |
| Coolingsystem: | Water-cooled |
| Power: | NaN0NaN0 |
| Torque: | NaN0NaN0 |
| Weight: | NaNlb |
The Buick V8 is a family of V8 engines produced by the Buick division of General Motors (GM) between 1953 and 1981. All were 90° water-cooled V8 OHV pushrod engines, and all were naturally aspirated except one turbocharged version of the 215.
The Buick V8 family can be divided into two sizes, big-blocks and small-blocks (block size classification refers to the engine block's bore spacing and external dimensions, not displacement). All 1953–1966 Buick V8s and the 1967–1976 "big-block" engines shared a 4.75inches bore spacing. The small-block was produced from 1961 to 1981.
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).
Buick's first generation V8 was offered from 1953 through 1956; it replaced the Buick straight-eight. While officially called the "Fireball V8"[1] 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.)[2]
During 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 [{{convert|1.75|in|abbr=on}} intake, {{convert|1.25|in|abbr=on}} exhaust], 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 (exceptional for the time).
First-generation Nailheads were painted "Late" Buick Green (also called Apple Green, used from 1953 to 1965).
The 2641NaN1 produced in 1954 and 1955 was a direct replacement for the 263 straight-eight and 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 its own smaller bore 3.625inches.
The larger 3221NaN1 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 NaNinches.
The 322 was also used in the 1956 through 1957 10,000-Series conventional-cab Chevrolet heavy duty trucks labeled as the Loadmaster.
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 foot pounds generated by each piston.[3] 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.
Buick, like most of its competitors, continued to expand their V8 engine to larger displacements. The 3641NaN1 was introduced in 1957 and produced through 1961, with a 4.125inchesx3.4inchesin (xin) (bore by stroke). The Special series cars came standard with the 250hp two-barrel carburetor version, where all other models got the 300hp four-barrel engine.
The 364 was enlarged to 4011NaN1 and produced from 1959 to 1966. Originally a 401, it was later redesignated a 400 to meet 1960s GM directives for maximum allowable engine displacements in mid-size cars. Bore and stroke were enlarged to 4.1875inchesx3.64inchesin (xin) respectively.
The 401/400 became Buick's muscle car powerplant of choice, 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 depending on the torque each version produced. The Wildcat 410 was the two-barrel carbureted engine, standard on the 1962-63 LeSabre. The Wildcat 375 was a no-cost option for the 1962-63 LeSabre that used a lower compression ratio to run on lower-octane fuel. The various Wildcat engines had decals on their air cleaners indicating their version; however, the four-barrel edition of the 1966-67 small-block Buick 340 V8 was also labeled Wildcat 375 on its air cleaner, but was not a Nailhead.
The Wildcat 445, with a single four-barrel carburetor, was the standard engine in the Invicta, 1959-1966 Electra, 1962–1966 Buick Wildcat, 1963 Riviera, and 1965 Riviera (the 1964 and 1966 Riviera models used the 425 with a single four-barrel carburetor, labeled Wildcat 465, as standard equipment).
In an effort to overcome the restrictive exhaust-port design of the Nailhead, Buick drag racing enthusiasts in the 1960s adapted superchargers with a custom camshaft to feed intake air in through the exhaust ports; the larger intake ports became the exhaust outlets.
The 4251NaN1 was produced from 1963 to 1966. Its bore and stroke measured 4.3125inchesx3.64inchesin (xin). The largest-displacement version of the Nailhead, it began as an option on the 1963 Riviera, and was later available on the Wildcat and Electra models. The 1964 and 1966 Rivieras used the 425 engine as standard equipment. Mounted on a trolley, Buick 425s were also used as starter motors for the SR-71 Blackbird supersonic jet.[4]
Four-barrel carburetion was standard on the basic 425, called the Wildcat 465 for the torque (as measured in lb-ft) it developed. The Super Wildcat (Regular Production Option -coded Y48) was available on the 1964 Riviera as a factory option (2,122 produced), 1964 Electras (any model, production numbers unknown), 1965 Riviera Gran Sport and 1966 Wildcat GS, which included two four-barrel carburetors and matching intake manifold. Coded "MW", these 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 cars were built with the MZ package.
Buick introduced its "Big Block" V8 in 1967 to replace the largest displacement Nailheads. It retained the 4.751NaN1 cylinder bore spacing and was produced in three displacements: 400, 430, and 455 cubic inches. Production continued through 1976.
The 4001NaN1 was produced from 1967-1969. This engine has a bore and a stroke ofNaN1NaN1. It was the only large V8 engine available for the intermediate-sized A-body Buicks due to the GM cubic inch limit restriction in effect through 1970.[5] 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.[6]
The 4301NaN1 was only produced from 1967 until 1969. This engine had a bore and a stroke of NaNinches. The 430 four-barrel engine was rated at 3600NaN0 and 4750NaN0 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:
The 400-based 4551NaN1 was produced from 1970–1976, with a bore x stroke of NaN1NaN1. Most parts (except pistons and heads) interchange between the 400 and the 430. The base model was rated at 3500NaN0, while the 455 Stage 1 equipped with a single 4-barrel Rochester Quadrajet carburetor was rated at 3600NaN0 at 4600 rpm.[10] [11] The regular 455 produced a rated 510lbft of torque at 2,800 rpm, more than any other muscle car engine. The horsepower was somewhat reduced in 1971 mainly due to the reduction in cylinder compression ratio, a change which was mandated by GM in order to cope with the introduction of new federal laws which would require new cars to use low octane gasoline in an effort to reduce exhaust emissions. Then, starting in 1972, the horsepower rating on paper would be reduced again due to a shift from SAE gross to SAE net, down to approximately 2500NaN0. Unleaded gasoline and catalytic converters came into play in 1975 for all US manufactured cars. Tightening emissions controls would cause the engine to drop in power still further, a little at a time, through 1976.
The 455 was one of the first "thin-wall casting" engine blocks at GM, and because of this[12] advance in production technology, it weighs significantly less than other engines of comparable size (for example, 150lb less than a Chevrolet 454[12] and only 25lb more than a Chevrolet 350).
Applications:
Buick introduced a "small block" V8 in 1961 with a 4.24inches cylinder bore spacing; it was produced in four displacements, 215, 300, 340, and 350. This design also became the basis of a highly successful cast iron V6 engine, the Fireball. Design features include an external oil pump, a forward-mounted distributor, and an integrated aluminum timing cover which incorporates the oil pump mechanisms, leaving the oil filter exposed to oncoming air for added cooling.
With the exception of the silver 1964 300, Buick small-blocks were painted "Late" Buick Green through 1966. Buick engines were painted red from 1967-1974, medium metallic blue from 1975-1977, and light blue from 1978-1982.
The small-block was originally produced as an industry-first all-aluminum engine. Alas, after 3 years of production, persisting cylinder liner issues, trumped with new and cheaper thin-wall iron casting techniques, pushed a change to an iron block.
See also Rover V8 engineGM experimented with aluminum engines starting in the early 1950s, when Aluminum Company of America (ALCOA) was pushing all automakers to use more aluminum. An early-development supercharged version of the 2151NaN1 V8 was used in the 1951 Le Sabre concept car,[18] and the 1953 Buick Roadmaster concept car.
GM designated Buick as engine design leader, and work on a production unit commenced in 1956. Originally intended for 1801NaN1 displacement, Buick decided on a larger, 2151NaN1 size, deemed ideal for the new Y-body cars introduced for 1961, like the Skylark.
Known as the Buick Fireball, the 215 had a bore and a stroke of NaN1NaN1, for an actual displacement of . With its aluminum cylinder heads and cylinder block, at the time it was the lightest mass-production V8 in the world, with a dry weight of only 318lb. Measuring 28inches long, 26inches wide, and 27inches high (same as the small-block Chevy),[19] it became standard equipment in the 1961 Buick Special.
At introduction, Buick's 215 was rated 1500NaN0 at 4400 rpm.[20] [21] This was raised soon after introduction to 1550NaN0 at 4,600 rpm. 2200NaN0 of torque was produced at 2,400 rpm with a Rochester 2GC (DualJet) two-barrel carburetor and 8.8:1 compression ratio. A mid-year introduction was the Buick Special Skylark version, which had 10.0:1 compression and a four-barrel carburetor, raising output to 1850NaN0 at 4,800 rpm and 2300NaN0 at 2,800 rpm.
For 1962, the four-barrel-equipped engine's compression ratio was increased to 10.25:1 and horsepower to 1900NaN0 at 4,800 rpm and 2350NaN0 at 3,000 rpm. The two-barrel engine was unchanged. For 1963, the four-barrel was bumped to 11.0:1 compression and an even 2000NaN0 at 5,000 rpm and 2400NaN0 at 3,200 rpm, NaNhp/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 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.
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 215hp Turbo-Rocket, in its 1962–63 Oldsmobile Jetfire.[22] 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 350lb. Intended to alleviate a head-warping problem on high-compression versions, Oldsmobile added a sixth head bolt on the intake manifold side. 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.[23] 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.
Casting-sealing technology was not advanced enough at that time, and hidden porosity problems caused serious oil leaks, producing an abnormally high scrap ratio.[21] The factory had to make extensive use of air gauging for leak checks, and was unable to detect leaks on blocks that were as much as 95% complete.[21] This raised the cost of complete engines to more than that of a comparable all cast-iron engine, so aluminum blocks were cancelled after the 1963 model year.[21] Another problem was clogged radiators from antifreeze mixtures incompatible with aluminum.[21]
The 215's very high power-to-weight ratio made it immediately interesting for automobile and boat racing. Mickey Thompson entered a stock-block 215-powered car in the 1962 Indianapolis 500, the first stock-block engine since 1946 and the only non-Offenhauser-powered entry in the race.[21] Rookie driver Dan Gurney qualified eighth and raced well for 92 laps before retiring with transmission problems.[21]
Surplus engine blocks of the Oldsmobile F85 version formed the basis of the Australian Formula One Repco V8[21] used by Brabham to win the 1966 Formula One world championship, although only the earliest engines had any Oldsmobile components.[21] The majority of Repco RB620 engines were cast and built in-house at Repco.[21]
Rights to these engines were purchased by the British Rover Company and used in the 1967 Rover P5B that replaced the 3 L straight six Rover engined P5. Throughout the years, the Rover Company (which became part of British Leyland in 1968), and its successor companies constantly improved the engine making it much stronger and more reliable. Capacities ranged from 215to. This engine was used for V8 versions of the MGB GT known as the GTV8. Rover also used the engine in the 1970 Range Rover. Morgan used the Rover version in its Plus 8.[24] American 215s have also been engine swapped into countless other platforms, especially Chevrolet Vegas[25] and later British cars including the MG RV8 in the 1990s,[26] Triumph TR8, and various sports sedans and sports cars by the MG Rover Group and specialist manufacturers such as TVR. The engine remains well-supported by enthusiast clubs, specialist parts suppliers, and by shops that specialize in conversions and tuning.
In 1964, Buick replaced the 215 with an iron-block engine of very similar architecture. The new "small block" engine had a bore of 3.751NaN1 and a stroke of 3.41NaN1 for a displacement of 3001NaN1. It retained the aluminum cylinder heads, intake manifold, and accessories of the 215 for a dry weight of 405lb. The 300 was offered in two-barrel form, with 9.0:1 compression, making 2100NaN0 at 4600 rpm and 3100NaN0 at 2400 rpm, and four-barrel form, with 11.0:1 compression, making 2500NaN0 at 4800 rpm and 3550NaN0 at 3000 rpm.
For 1965, the 300 switched to cast-iron heads, raising dry weight to 467lb, 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.[27] The Apollo 5000 GT sports car, (also sold as the Vetta Ventura) used this engine.
In 1966, the 300's stroke was increased to 3.851NaN1 in a raised block to create the 340 (3401NaN1) as a replacement for the four-barrel-carbureted 300. The taller deck (raised by 0.56251NaN1 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 2200NaN0 at 4,000 rpm and 3400NaN0 at 2,400 rpm, and the four barrel with 10.25:1 compression, rated at 2600NaN0 at 4,000 rpm and 3750NaN0 at 2,800 rpm. It was only produced through 1967, being replaced by the new small block 3501NaN1 in 1968.
Buick adopted the popular 3501NaN1 size in 1968 for their final family of V8 engines, the 350, which was produced through 1980. Although it shared the displacement of the other GM small blocks, including the Chevrolet 350, Oldsmobile 350, and Pontiac 350, the Buick blocks were of a substantially different proprietary company design. The Buick 350 featured the same 3.81NaN1 bore as the 2311NaN1 version of the Buick 90° V6 and retained the 3.851NaN1 stroke of the previous 3401NaN1 V8. The exact displacement is 349.310NaN0.
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, 31NaN1 crankshaft main journals, and 6.385inches connecting rods. Of all the GM "350s", the Buick has the longest piston stroke. This design characteristic made the engine significantly wider than the others — 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,[28] and some of its design characteristics are found in other Buick-designed GM engines, such as the 2311NaN1 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;[29] in these applications, the engine was billed as the Dauntless V8.
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:
The 2601NaN1 was an Oldsmobile V8 engine shared with Buick:[43]
The 3011NaN1 was a Pontiac V8 engine shared with Buick.[44]
The 3051NaN1 was a Chevrolet V8 engine shared with Buick:
The 3071NaN1 was an Oldsmobile V8 engine shared with Buick:[47]
The 4031NaN1 was an Oldsmobile V8 engine shared with Buick:[48]
| Years | Models | Color | |
|---|---|---|---|
| 1957-1966 | All | Apple "Late Buick" Green | |
| 1963 | Riviera | Silver | |
| 1966 | Riviera | Red | |
| 1967-1974 | All | Red | |
| 1975-1977 | All | Medium Metallic Blue | |
| 1978-1982 | All | Light Blue |
From the 1950s-1970s, each GM division had its own V8 engine family. Many were shared among other divisions, but each design is most-closely associated with its own division:
GM later standardized on the later generations of the Chevrolet design:
