Oldsmobile V8 engine


The Oldsmobile V8, also referred to as the Rocket, is series of engines that was produced by Oldsmobile beginning in 1949. The Rocket, along with the 1949 Cadillac V8, were the first post-war OHV V8 engines produced by General Motors. Like all other GM divisions, Olds continued building its own V8 engine family for decades, adopting the corporate Chevrolet 350 small-block and Cadillac Northstar engine only in the 1990s. All Oldsmobile V8s were manufactured at plants in Lansing, Michigan.
All Oldsmobile V8s use a 90° bank angle, and most share a common stroke dimension: for early Rockets, for later Generation 1 engines, and for Generation 2 starting in 1964. The,,, and engines are commonly called small-blocks.Hot Rod, 3/86, p.54.,, and V8s have a higher deck height to accommodate a stroke crank to increase displacement. These taller-deck models are commonly called "big-blocks", and are taller and wider than their "small-block" counterparts.
The Rocket V8 was the subject of many first and lasts in the automotive industry. It was the first mass-produced OHV V8, in 1949.
The factory painted "small-blocks" gold or blue, while "big-blocks" could be red, green, blue, or bronze.
As is the case with all pre-1972 American passenger car engines, published horsepower and torque figures for those years were SAE "Gross," as opposed to 1972 and later SAE Net ratings.

Generation I

The first generation of Oldsmobile V8s ranged from 1949-1964. Each engine in this generation is quite similar with the same size block and heads.

303

The engine had hydraulic lifters, an oversquare bore:stroke ratio, a counterweighted forged crankshaft, aluminum pistons, floating wristpins, and a dual-plane intake manifold. The 303 was produced from 1949-1953. Bore was and stroke was. Cadillac used a distantly related engine which appeared in three different sizes through to the 1962 model year; though the Oldsmobile and Cadillac motors were not physically related, many lessons learned by one division were incorporated into the others design, and the result were two engines known for their excellent power-to-weight ratio, fuel economy, and smooth, strong, reliable running.
The original Oldsmobile V8 was to have been marketed as "Kettering Power" after chief engineer Charles Kettering, but company policy prohibited the use of his name. Instead, the legendary Rocket was born, available in Oldsmobile's 88, Super 88, and 98 models. The engine proved so popular, the division's 88 models were popularly called Rocket 88s.
The 303 was available from 1949 through 1953. In 1949 through 1951 the 2-barrel carburetor 303 produced and, over 33% more power than the extremely popular and widely produced 1949 Ford Flathead V8. 1952 88 and Super 88 V8s used a 4-barrel carburetor for and, while 4-barrel 1953 versions upped the compression from 7.5:1 to 8.0:1 for and.
Applications:
The version was produced from 1954 until 1956. Bore was increased to and stroke remained the same at. Two-barrel carburetion was standard; all high performance 324s came with four-barrel carburetors. The 324 was shared with GMC trucks.
The 1954 88 and Super 88 V8s used an 8.25:1 compression ratio for and, respectively.
The 1955 model upped the compression to 8.5:1 for and in the 88 and and in the Super 88 and 98. For engines built during the first part of 1955, the 324 skirted pistons had a reputation for failing due to the cast aluminum skirt separating from its steel interior brace. This problem did not appear until the engine had over on it. By late 1956, many Olds dealers learned about the problem. Compression was up again in 1956 for and in the 88 and and in the Super 88 and 98.
Applications:
  • 1954–1956 Oldsmobile 88
  • 1954–1956 Oldsmobile Super 88
  • 1954–1956 Oldsmobile 98

    371

Making its debut in 1957 as standard equipment on all Olds models, the 371 was produced through 1960. Bore was now and stroke was increased to for. 1959 and 1960 371s used green painted valve covers. 4-barrel models used 9.25:1 compression in 1957 and 10:1 in 1958 for and and and respectively. A 1958 2-barrel version produced an impressive and, but had problems with early camshaft failures due to the high preload valve spring forces. Following the Automobile Manufacturer Association ban on factory supported racing, power ratings went down for the 1959 and 1960 88 models: and for 1959 and and for 1960. It was no longer available in cars in 1961.
This engine was used in GMC heavy trucks as the "370" of 232 gross HP at 4200 RPM and torque 355 gross lbs-ft at 2600 RPM from 1957 to 1959.It had hardened valve seats and other features for heavy duty usage.
Applications:
  • 1957–1960 Oldsmobile 88
  • 1957–1958 Oldsmobile Super 88
  • 1957–1958 Oldsmobile 98

    J-2 Golden Rocket

Introduced in the middle of the 1957 model year, the 1957 and 1958 J-2 Golden Rocket had three two-barrel carburetors with a vacuum-operated linkage. Only the center carburetor was mechanically connected to the throttle pedal, and it was the only one equipped with a choke. When the center carburetor was opened to 60° or more engine vacuum drawn from the windshield wiper pump would simultaneously open the front and rear carburetors. These carburetors did not open progressively; they were either open or closed. The J-2 engine also had a slightly thinner head gasket, raising compression to 10.0:1. It was advertised with gross power and torque ratings of at 4600 rpm and at 2800 rpm. Oldsmobile charged $83 for the J-2 option with the three-speed manual, $314 dollars with the automatic.
In practice, owners who did not regularly drive hard enough to engage the front and rear carburetors experienced problems with the linkage and carburetor throats becoming clogged, and some J-2-equipped cars had the front and rear carburetors removed and blocked off. Moreover, correct tuning was a continual headache. The package was expensive to produce, and Oldsmobile discontinued it after 1958.

394

Bore was up to for the largest first-generation Rocket, the. 394s were produced from 1959–1964 and were available on many Olds models. Most 394s used 2-barrel carburetors. Power was up to 315 hp, even though compression was down a quarter point, to 9.75:1.
The 394 replaced the 371 in Super 88 and 98 cars for 1959 and 1960 and a detuned version was used in the 88 for 1961 and the Dynamic 88 for 1962-1964.
Applications:
The 1961 through 1963 Sky Rocket was a high-compression, four-barrel engine. The 10:1 compression 1961 model produced and, while the 10.25:1 1962-1964 version upped power to and. A special 1963 10.5:1 version was also produced with.
Applications:
  • 1961–1963 Oldsmobile Dynamic 88
  • 1961–1964 Oldsmobile Super 88
  • 1961–1964 Oldsmobile 98

    Starfire

The high-compression four-barrel 394 cu. in. 1964 Starfire produced and for the 1963-4 Starfire and 98 Custom-Sports Coupe. It was optional on 1964 98s and Super 88s.

Aluminum 215

From 1961-1963, Oldsmobile manufactured its own version of the Buick-designed, all-aluminum 215 cubic inch V8 engine for the F-85 compact. Known variously as the Rockette, Cutlass, and Turbo-Rocket by Oldsmobile, it was a compact, lightweight engine measuring long, wide, and high, with a dry weight of only. The Oldsmobile engine was very similar to the Buick engine, but not identical: it had larger wedge combustion chambers with flat-topped pistons, six bolts rather than five per cylinder, and slightly larger intake valves; the valves were actuated by shaft-mounted rocker arms like the Buick and Pontiac versions, but the shafts and rockers were unique to Oldsmobile. With an 8.75:1 compression ratio and a 2-barrel carburetor, the Olds 215 had the same rated hp, at 4800 rpm, as the Buick 215, with of torque at 2400 rpm. With a 4-barrel carburetor and 10.25:1 compression, the Olds 215 made at 4800 rpm and at 3200 rpm with a manual transmission. With a 4-barrel carburetor and 10.75:1 compression, the Olds 215 made at 4800 rpm and at 3200 rpm with an automatic. The Buick version was rated at 200 hp with an 11:1 compression ratio.
The Buick version of the 215 V8 went on to become the well known Rover V8, which still remains in limited production, utilizing the Buick-style pistons, heads, and valve train gear.
The Oldsmobile engine block formed the basis of the Repco 3-liter engine used by Brabham to win the 1966 and 1967 Formula One world championships. The early Repco engines produced up to, and featured new SOHC cylinder heads and iron cylinder liners. The 1967 and later versions of the Repco engine had proprietary engine blocks.
In the mid-1980s, hot rodders discovered the 215 could be stretched to as much as, using the Buick 300 crankshaft, new cylinder sleeves, and an assortment of non-GM parts. 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 is theoretically possible.

Turbo-Rocket

In 1962 and 1963 Oldsmobile built a turbocharged version of the 215, designated Turbo-Rocket. The turbocharger fitted to the V8 engine was a small-diameter Garrett T5 model with integral wastegate, manufactured by Garrett AiResearch, and produced a maximum of 5 psi boost at 2200 rpm. The engine had 10.25:1 compression and a single-barrel carburetor. It was rated at at 4600 rpm and at 3200 rpm. In development, the high compression ratio combined with the charged load created problems with spark knock on hard throttle applications, which led Olds to develop and utilize a novel water-injection system that sprayed metered amounts of distilled water and methyl alcohol into the intake manifold air-stream to cool the intake charge. If the fluid reservoir was empty, a complex double-float and valve assembly in the Turbo-Rocket Fluid path would set a second butterfly into the closed position, limiting the amount of boost pressure. Unfortunately, many customers did not keep the reservoir filled, or had mechanical problems with the turbocharger system which resulted in many of the turbo-charger installations being removed and a conventional 4 barrel carburetor and manifold installed in its place.
The Turbo-Rocket V8 was offered exclusively on the Oldsmobile Jetfire, a special version of the Cutlass compact hardtop coupe, which is noteworthy as it one of the world's first turbocharged passenger car ever offered for public sale. The Chevrolet Corvair Spyder Turbo, likewise a forced induction i.e turbo-powered car, predated the Oldsmobile Jetfire Turbo, however by only a few weeks, thus being the world's very first turbocharged commercially sold vehicle.

Generation II

The second generation of Oldsmobile V8s was produced from 1964-1990. Most of these engines were very similar, using the same bore centers and a deck height, raised on "big-block" versions to. Big-block and Diesel versions also increased the main bearing journal to for increased strength. All generation-2 small-block Olds V8s used a stroke of. The big-block engines initially used a forged crankshaft with a stroke of 3.975" for the 1965-1967 425 and 400 CID versions; starting in 1968, both the and the big blocks used a stroke of, with crankshaft material changed to cast iron except in a few rare cases.
These were wedge-head engines with a unique combustion chamber that resulted from a valve angle of only 6°. This was much flatter than the 23° of the small-block Chevrolet and 20° of the Ford small-block wedge heads. This very open and flat chamber was fuel efficient and had lower than average emissions output. It was the only GM engine to meet US emission standards using a carburetor all the way up to 1990.

330

The first second-generation Oldmobile V8 "Jetfire Rocket" introduced in 1964 and produced through 1967. It was released one year earlier than the tall deck 425, and debuted the standard stroke; bore was. 330s were painted gold and had forged steel crankshafts. The 4 barrel versions had a larger diameter harmonic damper, the 2 barrel only a balancer hub without the rubberized outer ring.

400

The version was the second tall-deck "big-block" Olds. Two distinct versions of the 400 CID engine were made:
  • 1965-1967 "Early" 400s used a slightly oversquare bore and stroke for an overall displacement of. All the pre-1968 engines used a forged steel crankshaft.
  • 1968 and 1969 400s shared the Olds big-block standard stroke with the 455 but used a very undersquare bore to comply with GM's displacement restrictions in the A-body cars while also reducing tooling costs. Displacement is very close to the earlier engine, at. This "later" 400 is considered less desirable by many enthusiasts, because of the power band characteristics induced by this exceedingly undersquare format, although the actual change in power was due to the mild 250/264 duration cam used in this engine and the fact that the crankshafts were now made of less durable high nodular iron material.

    4-4-2 Rocket

The 1967 400 engine was a short stroke 1966-1967 only engine. It featured B and C cast large valve cylinder heads and hydraulic lifters are larger in diameter and push rods are different length and diameter than the standard Olds Rocket V8 it was rated at 350 horsepower and 440 lb/ft of torque with a Rochester 4 barrel and 360 hp with the L69 tri 2 barrel option in 1966 and 360 hp in 1967 it was equipped with a W30 camshaft and outside air induction, 502 factory examples of this engine were produced. They were all painted Bronze and had V and G stamped on the cylinder heads. V8.

425

The big-block was the first tall-deck "big block," produced from 1965 through 1967. It is arguably the best engine Olds made in the muscle car era, although it never made it into a "muscle car". It used a bore and stroke. Most 425s were painted red, though the 1966 and 1967 Toronado units were light blue. All 425 engines were fitted with forged steel crankshafts with harmonic balancers.

Super Rocket

The standard 1965-1967 was called the Super Rocket, and was the most powerful engine option for the Oldsmobile 88 and 98 of 1965-1967. Compression ratios of 9.0:1 at or 10.25:1 at were available in the U.S.

Starfire

A special 1965-1967 V8 was the Starfire engine. The main distinguishing features of this engine were a slightly different camshaft profile from the standard ultra high compression engine and factory dual exhaust. This engine was only available in the Oldsmobile Starfire and a performance economy model called the Jetstar I. It shared the same compression ratio of the Toronado Rocket at 10.5:1. It also used the.921 in lifter bore size of the Toronado Rocket.

Toronado Rocket

An Ultra High Compression Toronado Rocket version of the V8 was made for the 1966 Toronado. It had the same -diameter lifters of the first-generation Oldsmobile engines, rather than the standard, which let engineers increase the camshaft's ramp speed for more power,, without sacrificing idle or reliability. Unlike all other 425s, this version was painted slate blue metallic.

455

The 425's stroke was lengthened to to achieve a to create the Rocket 455 for 1968. It kept the retired 425's bore to produce between. Initially the paint was red, except for metallic blue in the Toronado applications; 1970-1976 versions were metallic blue at first, then nonmetallic blue. The "Rocket" name disappeared from the air cleaner identification decal after 1974. Although production of the 455 ended in 1976, a small number were produced through 1978 for power equipment use, such as motorhomes, boats and irrigation equipment.
Applications:
Produced from 1968–1980, the Rocket 350 was entirely different from the other GM divisions' 350s. It used a bore and Oldsmobile small-block standard stroke for. Output ranged from 160-325 hp. 1968-1974 350s were painted gold; 1975-1976 350s were metallic blue like the 455; 1977-1980 models were painted GM Corporate Blue. The "Rocket" name disappeared from the air cleaner decal in 1975, the same year that the catalytic converter was added to the emissions control system.
The Oldsmobile 350s made from 1968-1976 have heavy castings, beefier crankshafts, and better flowing heads. The 1977-1980 350s have lighter castings, including a thinner block with large "windows" in the main bearing bulkheads, and have crack-prone cylinder head castings manufactured by Pontiac Motor Division, and a lightened crankshaft. Some later versions of this 350 were produced with an analog electronic port fuel injection system, introduced in the Cadillac Seville of 1976.
Applications:
Oldsmobile's own L34 V8 was used in the 1976 Oldsmobile Cutlass "S", 1979 Hurst/Olds models and 1980 "4-4-2". The L34 used a 4-barrel carburetor and produced and.

403

The 455 big block Olds V8 was replaced in 1977 with the small block, which used a bore, the largest ever used in a small-block V8, with the Olds small-block standard deck and stroke. The bore was so wide that the cylinder walls were siamesed, as in the Chevrolet 400 V8, with no space for coolant to flow between the cylinders. This sometimes led to overheating problems. Some very early 403s were painted metallic blue like the 455, but most were painted GM Corporate Blue.
The Olds 403 was used by Buick and Pontiac in addition to Oldsmobile until its discontinuation after 1979. Output was and. Uniquely in the 1977 Toronado, the 403 engine was fitted with a crank triggered ignition system. Parts peculiar to this system include a toothed disc between the harmonic balancer and the crank pulley, the "adjacent sensor", a special distributor, an engine temperature sensor, and a rudimentary computer mounted inside the car, under the dashboard.
Applications:
A smaller V8 was created in 1975 by decreasing the bore to. It produced and., and had a sales code of LV8. This was the first engine to use the smaller Rochester Dualjet two-barrel carburetor, the only carburetor used on the 260. Production of the 260 V8 ended in 1982 when the 307 became the only gasoline V8 in Oldsmobile's line. The 260 was designed for economy, and was the first engine option above the 3.8 L Buick V6 standard in many Oldsmobile models by the late 1970s. While the 260s were not very powerful compared to the larger 350 and 403 V8s, fuel economy was almost as good as the base V6. Compared to the V6, the 260 was also smoother-running, and far more durable. Most 260s were coupled to the Turbo Hydramatic 200 transmission, but a 5-speed manual transmission was also available in some vehicles.
Applications:
A slightly larger version was introduced in 1980, with a bore and a stroke. Some early 307s were painted GM Corporate blue, but most were painted satin black. The 307 was used in most Oldsmobile models as well as certain Buicks, Cadillacs, Chevrolets, and Pontiacs. Every 307 used one or another variant of the Rochester Quadrajet 4-barrel carburetor.
The horsepower output of the 307 wasn't particularly high; the standard-specification 307 in the 1983 Oldsmobile 98 put out, although in that year a high-output version was available producing a nominal and torque. The final 1990 configuration was rated at at 3200 rpm and of torque at 2000 rpm. The combination of good low-RPM torque, the Quadrajet four-barrel carburetor, and the THM-200-4R four-speed overdrive automatic transmission with lockup torque converter allowed for fairly good performance, and fuel economy considered reasonable for the era, even in the larger and heavier model cars. The engine is also known for its reliability, smoothness and quietness.
Applications:
  • 1980–1985 Oldsmobile 88
  • 1980–1984 Oldsmobile 98
  • 1980–1985 Oldsmobile Toronado
  • 1980–1990 Oldsmobile Custom Cruiser
  • 1980–1985 Buick Lesabre
  • 1980–1984 Buick Electra
  • 1980–1985 Buick Riviera
  • 1980–1990 Buick Estate Wagon
  • 1986–1987 Buick Regal
  • 1986–1990 Chevrolet Caprice Wagon
  • 1986–1987 Cadillac Brougham VIN "9"
  • 1981 Pontiac Bonneville
  • 1986 Pontiac Parisienne The 307 was fitted in some late model 1986 Parisienne's while others had the Chevy 305

    LV2

The LV2 307 was offered from 1980-1990 by every domestic GM passenger car marque except Saturn. In 1985, roller lifters, floating piston wrist pins, and swirl port intake runners were added. The 307 "Y" produced and in 1980-1984 models and and in 1985-1990s.
Y-version applications:
  • 1980–1985 Buick Lesabre
  • 1980–1985 Buick Riviera
  • 1986–1987 Buick Regal
  • 1986–1990 Chevrolet Caprice
  • 1980–1985 Oldsmobile 88
  • 1980–1984 Oldsmobile 98
  • 1980–1985 Oldsmobile Toronado
  • 1980–1990 Oldsmobile Custom Cruiser
  • 1980–1981 Oldsmobile Cutlass
  • 1982–1987 Oldsmobile Cutlass Supreme
  • 1988 Oldsmobile Cutlass Supreme Classic
  • 1982–1986 Pontiac Parisienne VIN "Y"
  • 1988–1990 Cadillac Brougham VIN "Y"

    LG8

The LG8 was an updated version of the 307 produced from 1983 to 1987. Performance modifications included a more aggressive camshaft, stiffer valve springs, a larger vibration damper, a Y-pipe dual-outlet exhaust system, and richer secondary metering rods in the carburetor. It was offered in the Hurst/Olds version of the Oldsmobile Cutlass Calais and in the 4-4-2 version of the Oldsmobile Cutlass Salon. Output for 1983-1985 was and. Revisions to the engine for 1986 included roller lifters with a slightly smaller camshaft, new heads with smaller, swirl-port intake runners, floating piston pins, and larger piston dishes for lower compression. These changes increased torque to but lowered power to, while lowering the RPM at which peak power and torque were achieved.
Applications:
  • 1983–1984 Hurst/Olds
  • 1985–1987 Oldsmobile 4-4-2
  • 1985–1988 Cadillac Brougham VIN "9"

    Generation 3

The Generation II V8 ended production in 1990. The company later introduced a new vehicle, the Oldsmobile Aurora, with a new generation V8. Based on the Cadillac Northstar engine, this, called Aurora, was a DOHC design.
From the 1950s through the late 1970s, each GM division had its own V8 engine family. Many were shared among other divisions, but each design was unique:
  • Buick V8 engine
  • Cadillac V8 engine
  • Chevrolet Small-Block engine
  • Chevrolet Big-Block engine
  • Pontiac V8 engine
  • Holden V8 engine
GM later standardized on the later generations of the Chevrolet design:
  • GM LT engine - Generation II small-block
  • GM LS engine - Generation III/IV small-block
  • List of GM engines