Buick V8 engine

Like its sister General Motors divisions, Buick produced its own family of V8 engines to replace its straight-8 engines. These engines came in many of the same displacements as those from other divisions, but were entirely different.

Buick "Nailhead V8"

Buick first generation of V8 lasted from 1953 through 1956. It was an OHV/pushrod engine like the then new Oldsmobile "Rocket V8" engine. This engine became known as the "Nailhead" for the unusual vertical position of its small-sized valves—which looked like nails. The Nailhead-V8 family employed a camshaft with higher lift and longer duration to offset the smaller-sized valves and arguably restrictive intake- and exhaust-port areas. The small-size valves and intake runners made for engines with a lot of torque, with many exceeding one foot-pound per cubic inch, which was exceptional for the day.

264

The 264 cu in (4.3 L) 264 was a direct replacement for the 263 straight-8 in Series 40 Buicks. It was produced in 1954 and 1955. The smallest displacement Nailhead was the only engine available for the economy "Special" Series 40 through 1955.

322

The larger 322 cu in (5.3 L) 322 was used by Buick from 1953 through 1956 in the Roadmaster, Super and Century models, and finally in the Special in 1956.

Nailhead V8

Buick's second variation of this V8 was also named Nailhead. It was produced from 1957-1966.

364

The 364 was introduced in 1957. The Special came standard with 2bbl carb and 250 hp where all others had the 4bbl, 300 hp engine. Buick, like most of its competitors, continued to expand their durable V8 engine to larger displacements such as the 364 in³ (4.125in bore)x(3.40in stroke)= 364 cubic inches (6.0 L).

400

The next member of the family was the 401 cu in (6.6 L) 400. This was actually a 401 that had been redesignated a "400" in order to meet GM directives for maximum displacement engines in mid-size cars.

Another Buick "400" engine was a member of the 400/430/455 family and was produced from 1967-1969.

401

The 401 cu in (6.6 L) 401 was Buick's muscle car powerplant of choice, and was found in the company's Skylark Gran Sport and Buick Wildcat, among others. As unlikely as it seems, the air cleaner for the engine is annotated with "Wildcat 375" "Wildcat 410" "Wildcat 445" these inscriptions indicated not the cubic inches displaced but the ft·lbf of torque produced by the engine. The "Wildcat 410" was the 2-barrel carburated engine that was standard on the 1962-63 LeSabre. The "Wildcat 375" was a no cost option on the 62-63 LeSabre that had lower compression to run on regular fuel (another Buick V8 had "Wildcat 375" written on its air cleaner but it wasn't a "Nailhead", it was the 4-barrel version of the 66-67 small block Buick 340). The "Wildcat 445" had a single 4 barrel carb. It was the standard engine on the Invicta, 1959-66 Electra, 1962-66 Buick Wildcat, 1963 Riviera and 1965 Riviera (the 64 and 66 Riviera models had a 425 in³ engine with a single 4 barrel carb. named "Wildcat 465" as standard equipment). These were also used as starter motors for the SR-71 Blackbird, mounted on a trolley.

In an effort to overcome the "restrictive" exhaust port design, Buick enthusiast drag racers in the sixties adapted superchargers with a custom camshaft to feed intake air in through the exhaust ports and used the larger intake ports for exhaust outlets. Perhaps this feat of ingenuity, and the unusual appearance of the engine modified in this manner, also intimidated rival racers and added to the Nailhead V8 legend that lives upon this page of US auto history.

425

425 cu in (7.0 L) 425

This was the largest version of the "Nailhead". It began as an option in 1963 on the Riviera and it was later available on the Wildcat and Electra models too. The 1964 and 1966 Riviera had the 425 engine as standard equipment.

4 barrel carburetion was standard on all 425 "Nailheads" that were called "Wildcat 465". The "465" sticker on the air cleaner did not denote engine displacement as many thought, it denoted the torque rating. It was possible to order two 4 barrel carbs, which were delivered in the trunk along with the intake manifold and installed by the dealer. This version was called "Super Wildcat" and could be ordered on the 1965 Riviera Gran Sport and the 1966 Wildcat GS as RPO Y48. Toward the end of the 1966 model year, approximately May 1966, Buick offered the Super Wildcat 465 with dual 4BBL Carter AFB's as a factory installed option. This engine is coded "MZ" while the dealer installed dual four barrel setup was a "MW" coded engine. There were only 179 1966 Riviera GS cars built with the MZ coded factory dual four barrel setup, making it a very rare car. Rarer still was the 1966 Riviera GS, MZ coded engine, in Riviera Red exterior color.

Buick "Small-Block"

In 1961, Buick unveiled an entirely new small V8 engine with aluminum cylinder heads and cylinder block. Lightweight and powerful, the aluminum V8 also spawned a turbocharged version, (only in the 1962-63 Oldsmobile Cutlass version), the first ever offered in a passenger car. It became the basis of a highly successful cast iron V6 engine, the Fireball. The all-aluminum engine was dropped after the 1963 model year, but was replaced with a very similar cast-iron engine.

215

See also Rover V8 engine

GM experimented with aluminum engines starting in the early 1950s. An early development model was used in the 1951 Le Sabre concept car,<ref>Flory, J. "Kelly", Jr. American Cars 1946-1959 (Jefferson, NC: McFarland & Coy, 2008), p.1021.</ref> and work on a production unit commenced in 1956. Originally intended for 180-cubic-inch (2.9 L) displacement, Buick was designated by GM as the engine design leader, and decided to begin with a larger, 215-cubic-inch (3.5 L) size, which was deemed ideal for the new "senior compact cars" introduced for the 1961 model year. This group of cars was commonly referred to as the "B-O-P" group — for Buick-Olds-Pontiac — or the Y-bodies.

Known variously as the Fireball and Skylark by Buick (and as Rockette, Cutlass, and Turbo-Rocket by Oldsmobile),<ref>Depending on carburetion or use of turbocharger. Flory, J. "Kelly", Jr. American Cars 1960-1972 (Jefferson, NC: McFarland & Coy, 2004), pp.205 & 246.</ref> the 215 had a 4.24 in (108 mm) bore spacing, a bore of 3.5 in (89 mm), and a stroke of 2.8 in (71 mm), for an actual displacement of 215.5 cu in (3,531 cc). The engine was the lightest mass-production V8 in the world, with a dry weight of only 318 lb (144 kg). Measuring 28 in (71 cm) long, 26 in (66 cm) wide, and 27 in (69 cm) high (same as the small-block Chevy)<ref>Baechtel, John. "Alternative Engines: Part 2--Buick V8", in Hot Rod Magazine, 11/84, p.67.</ref> it was standard equipment in the 1961 Buick Special.

Oldsmobile and Pontiac also used the all-aluminum 215 on its mid-sized cars, the Oldsmobile F-85, Cutlass and Jetfire, and Pontiac Tempest and LeMans. Pontiac used the Buick version of the 215; Oldsmobile had its own. The Oldsmobile version of this engine, although sharing the same basic architecture, had cylinder heads designed by Oldsmobile engineers, and was produced on a separate assembly line. Among the differences between the Oldsmobile and Buick versions, it was somewhat heavier, at 350 lb (160 kg). The design differences were in the cylinder heads: Buick used a 5-bolt pattern around each cylinder where Oldsmobile went to a 6-bolt pattern. The 6th bolt was added to the intake manifold side of the head, one extra bolt for each cylinder, meant to alleviate a head-warping problem on high-compression versions. This meant that Oldsmobile heads would go on Buick blocks, but not vice versa, and that changing the compression ratio on an Oldsmobile 215 required changing the heads, but on a Buick 215, only the pistons, which was less expensive and simpler. For these reasons, the more common Buick version has today also emerged as more desirable. Later Rover versions of the aluminum block and subsequent Buick iron small blocks (300, 340, and 350) went to a 4-bolt-per-cylinder pattern.

At introduction, Buick's 215 was rated 150 hp (110 kW) at 4400 rpm. This was raised soon after introduction to 155 hp (116 kW) at 4600 rpm. 220 ft·lb (298 N·m) of torque was produced at 2400 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 10.25:1 compression and a four-barrel carburetor, raising output to 185 hp (138 kW) at 4800 rpm and 230 ft·lb (312 N·m) at 2800 rpm.

For 1962, the four-barrel engine increased the compression ratio to 10.25:1, raising it to 190 hp (140 kW) at 4800 rpm and 235 ft·lb (319 N·m) at 3000 rpm. The two-barrel engine was unchanged. For 1963, the four-barrel was bumped to 11:1 compression and an even 200 hp (150 kW) at 5000 rpm and 240 ft·lb (325 N·m) at 3200 rpm, a respectable 0.93 hp/cu in (56.6 hp/L).

Unfortunately, the great expense of the aluminum engine led to its cancellation after the 1963 model year. The engine had an abnormally high scrap ratio due to hidden block-casting porosity problems, which caused serious oil leaks. Another problem was clogged radiators from antifreeze mixtures incompatible with aluminum. It was said that one of the major problems was because they had to make extensive use of air gauging to check for casting leaks during the manufacturing process, and not being able to detect leaks on blocks that were as much as 95% complete. This raised the cost of complete engines to more than that of a comparable all cast-iron engine. Casting sealing technology was not advanced enough at that time to prevent the high scrap rates.

The Buick 215's very high power to weight ratio made it immediately interesting for automotive and marine racing. Mickey Thompson entered a stock-block Buick 215-powered car in the 1962 Indianapolis 500. From 1946-1962, there hadn't been a single stock-block car in this famous race. In 1962, the Buick 215 was the only non-Offenhauser powered entry in the field of 33 cars. Rookie driver Dan Gurney qualified eighth and raced well for 92 laps before retiring with transmission problems.

Surplus engine blocks of the Oldsmobile (6 bolt per cylinder) version of this engine formed the basis of the Formula One Repco V8 used by Brabham to win the 1966 and 1967 Formula One world championship. No other American stock-block engine has won a Formula One championship.

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 Co., which became part of British Leyland in 1968, and its successor companies constantly improved the engine making it much stronger and reliable. Capacities ranged from 3.5-5.0 L (215 to 307 in³). This engine was used for V8 versions of the MGB-GT known as the MGB GTV8. This came straight from the MG works at Abingdon-on-the-Thames. Rover also used the engine in the 1970 Range Rover which saw the engine successfully returning to the USA after the Range Rover's 1986 introduction. U.S. Buick 215s have also been engine swapped into countless other platforms, especially Chevrolet Vegas and later British cars MG sports cars including the MG RV8 in the 1990s. Triumph TR-8, and various sports sedans and sports cars by the MG Rover Group and some specialist manufacturers such as TVR and the Morgan Motor Company. The engine remains well supported by enthusiast clubs, specialist parts suppliers, and by shops that specialise in conversions and tuning.

The 215 was also used in a small sports car known as the Apollo in 1962-1963, as well as in the Asardo 3500 GM-S show car.

Although dropped by GM in 1963, the Rover V8 engine would remain in use for more than 35 years. GM tried to buy it back later on, but Rover declined, instead offering to sell engines back to GM. GM refused this offer.

In the mid-1980s, hot rodders discovered the 215 could be stretched to as much as 305 cu in (5 l), using the Buick 300 crankshaft, new cylinder sleeves, and an assortment of non-Buick parts.<ref>Davis, Marlan. "Affordable Aluminum V8's [sic]", in Hot Rod Magazine, March 1985, pp.84-9 & 121.</ref> It could also be fitted with high-compression cylinder heads from the Morgan +8. Using the 5 liter Rover block and crankshaft, a maximum displacement of 317.8 cu in (5,208 cc) is theoretically possible.<ref>Davis, p.87.</ref>

300

In 1964, Buick replaced the 215 with an iron-block engine of very similar architecture. The new engine had a bore of 3.75 in (95 mm) and a stroke of 3.40 in (86 mm) for a displacement of 300.4 cubic inches (4,923 cc). It retained the aluminum cylinder heads, intake manifold, and accessories of the 215 for a dry weight of 405 lb (184 kg). The 300 was offered in two-barrel form, with 9.0:1 compression, making 210 hp (160 kW) @ 4600 rpm and 310 lb·ft (420 N·m) @ 2400 rpm, and four-barrel form, with 11.0:1 compression, making 250 hp (190 kW) @ 4800 rpm and 335 lb·ft (454 N·m) @ 3000 rpm.

For 1965, the 300 switched to a cast-iron heads, raising dry weight to 467 lb (212 kg), 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.

The Apollo sports car, also known as the Vetta Ventura, used this engine.

340

The 340 cu in (5.6 L) 340 was a stroked (to 3.85 in (98 mm)) version of the 300. It had a two- or four-barrel carburetor, the two-barrel with compression of 9 to 1 comp. ratio rated at 220 hp (160 kW) at 4000 rpm and 340 lb·ft (460 N·m) at 2400 rpm, and the four barrel with 10.25 to 1 comp ratio, rated at 260 hp (190 kW) @ 4000 rpm and 365 lb·ft (495 N·m) @ 2800 rpm. It replaced the four-barrel 300 for 1966. It was produced only in 1966 and 1967, with the new Buick 350 taking its place after that.

350

Buick adopted the popular 350 cu in (5.7 L) size with their final family of V8s. Although sharing the displacement of the Chevrolet Small-Block engine family, the Buicks were substantially different.

The Buick 350 V8 had a 3.80 in (97 mm) bore (like the 231) and retained the 3.85 in (98 mm) stroke of the 340. It was introduced in 1968 and produced through 1980. Its nickname is "Dauntless."

The major differences of the Buick 350 when compared to other GM V8's are deep skirt block construction, higher nickel-content cast iron, external oil pump, under square bore sizing, 3 in (76 mm) crank main journals, and 6.385 in (162.2 mm) connecting rods. It is an extremely rugged and durable engine, and some of the design characteristics of the Buick 350 are found in modern GM engines such as the 231 V6, and Series I, II, and III 3800 V6's.

Of all the GM 350-cubic-inch (5.7 L) engines, the Buick 350 has the longest stroke, which lends to making significantly more torque than any of the others. It also made the Buick 350 significantly wider — essentially the same width as the Buick big-blocks, which have the shortest stroke of the GM big-blocks. In fact, at a glance the Buick 350 is commonly mistaken for the 455 engine due to the oversized intake manifold atop the engine. The Buick 350 also shares an integrated aluminum timing cover as do most of the Buick small and big blocks which incorporates the oil pump mechanisms as well, leaving the oil filter exposed to oncoming air for added cooling.

The Buick 350 was used in the Jeep Gladiator and Wagoneer from 1968-1971.

Buick "Big-Block"

The company introduced a larger engine family to replace the "Nailhead" in 1967 and was produced through 1976.

400

The 399.95-cubic-inch (6,554.0 cc) 400 was produced from 1967-1969. This engine had a bore of 4.04 in (103 mm) and a stroke of 3.90 in (99 mm). It was the only large V8 engine available for the A-body Buicks due to the GM cubic inch limit restriction prior to 1970. Most parts except the pistons interchange with the 430 and 455.

430

The 429.69-cubic-inch (7,041.4 cc) 430 was produced from 1967-1969. This engine had a bore of 4.1875 in (106.36 mm) and a stroke of 3.90 in (99 mm). This engine was used in B-, C- and E-body (large body) Buicks. Most parts except the pistons interchange with the 400 and 455.

455

The 455.72-cubic-inch (7,467.9 cc) 455 Buick V8 used a 4.3125 in (109.54 mm) bore and a 3.90 in (99 mm) stroke. It was produced from 1970–1976 and was based on the 400/430 V8. The regular Buick 455 was rated at 350 hp (260 kW), while the 455 Stage 1 was underrated at 360 hp (270 kW). In all actuality, the Stage 1 produced around 425 hp (317 kW). The regular 455 produced a rated 510 ft·lbf (690 N·m) of torque at 2800 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 unleaded gasoline in an effort to reduce exhaust emissions. Then, starting in 1972, the horsepower rating on paper would be reduced again, down to approximately 250 hp (190 kW), this time due to the new measurement of horsepower as SAE net horsepower, rather than a gross horsepower rating. Tightening emissions controls would cause the engine to drop in power still further, a little at a time, through 1976. Most parts (except the pistons) interchange between the 400 and the 430. The 455 was one of the first "thin-wall casting" engine blocks, and because of this advance in production technology it weighs significantly less than other engines of comparable size (for example, 150 lb (68 kg) less than a Chevrolet 454).

Non-Buick V8s powering Buick Vehicles

In the mid-1970s, GM was using powerplants sourced from various GM divisions where the Buick V8 was considered a factory option with the Buick 350 as the sole survivor, or in the worst case, for Buick vehicles where the 400/430/455 big blocks were phased out because of fuel economy/emission requirements.

403

The 403 cu in (6.6 L) engine used in Buicks was actually an Oldsmobile V8 engine.

Buick V8 engine

Contents

Buick "Nailhead V8"

264

322

Nailhead V8

364

400

401

425

Buick "Small-Block"

215

300

340

350

Buick "Big-Block"

400

430

455

Non-Buick V8s powering Buick Vehicles

260

301

305

307

403

See also

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