The 1967 Toronado's 425 V8, the first front-wheel drive V8 application.
The Oldsmobile Rocket V8 was the first post-war OHV V8 at General Motors. Production started in 1949, with a new generation introduced in 1964. Like Pontiac, Olds continued building its own V8 engine family for decades, finally adopting the corporate Chevrolet 350 small-block and Cadillac Northstar engine only in the 1990s.
All Oldsmobile V8s use a 90° bank angle, and most share a common stroke dimension: 3.4375 in (87.3 mm) for early Rockets, 3.6875 in (93.7 mm) for later Generation 1 motors, and 3.385 in (86 mm) for Generation 2. The engine could be classified as a small-block, but Oldsmobile used a higher deck height for a 4.25 in (107.9 mm) stroke to boost displacement to a big-block-like 455 in³ (7.5 L).
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; and was the last carbureted V8 passenger car engine in 1990.
The first generation of Oldsmobile V8s ranges from 1949 until 1964. Each engine in this generation is quite similar with the same size block and heads.
The 303 in³ (5.0 L) 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 until 1953. Bore was 3.75 in (95.2 mm) and stroke was 3.4375 in (87.3 mm). Cadillac also used this engine design in the early 1950s.
The 303 was available from 1949 through 1953. 1949 through 1951 "88" 303's came with a 2-barrel carburetor for 135 hp (100 kW) and 253 ft·lbf (343 N·m). 1952 88 and Super 88 V8s used a 4-barrel carb for 160 hp (119 kW) and 265 ft·lbf (359 N·m), while 1953 versions upped the compression from 7.5:1 to 8.0:1 for 165 hp (123 kW) and 275 ft·lbf (372 N·m). For comparison, a 1949 Ford Flathead V8 produced just 100 hp (74 kW).
The 324 in³ (5.3 L) version was also produced from 1954 until 1956. Bore was increased to 3.875 in (98.4 mm) and stroke remained the same at 3.4375 in (87.3 mm). All high performance 324s came with 4-barrel carburetors. The 324 was shared with GMC trucks.
1954 88 and Super 88 V8s used an 8.25:1 compression ratio for 170 and 185 hp (126 and 137 kW) and 295 and 300 ft·lbf (399 and 406 N·m) respectively. 1955 upped the compression to 8.5:1 for 185 hp (137 kW) and 320 ft·lbf (433 N·m) in the 88 and 202 hp (150 kW) and 332 ft·lbf (450 N·m) in the Super 88 and 98. Compression was up again in 1956 for 230 hp (171 kW) and 340 ft·lbf (460 N·m) in the 88 and 240 hp (178 kW) and 350 ft·lbf (474 N·m) in the Super 88 and 98.
A special 370 in³ (6.1 L) variant called the 370 was used in GMC trucks alone, not shared.
371s were produced from 1957 through 1963. Bore was now 4.0 in (101.6 mm) and stroke was increased to 3.6875 in (93.7 mm) for 371 in³ (6.1 L). 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 277 hp (206 kW) and 400 ft·lbf (542 N·m) and 305 hp (227 kW) and 410 ft·lbf (555 N·m) respectively. A 1958 2-barrel version was still impressive at 265 hp (197 kW) and 390 ft·lbf (528 N·m), but power nosed downward for the 1959 and 1960 88 model: 270 hp (201 kW) and 390 ft·lbf (528 N·m) for 1959 and 240 hp (178 kW) and 375 ft·lbf (508 N·m) for 1960.
The 371 was also used in GMC trucks.
The 1957 and 1958 J-2 Golden Rocket produced 312 hp (232 kW) and 415 ft·lbf (562 N·m) with a tri-power six-barrel carburetor.
Bore was up to 4.125 in (104.8 mm) for the largest first-generation Rocket, the 394 in³ (6.5 L). 394s were produced from 1959 through 1964 and were available on many Olds models. Most 394s used 2-barrel carburetors.
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 through 1964.
The 1961 through 1963 Sky Rocket (and 1964 Rocket) was a 394 in³ (6.5 L) engine. The 10:1 compression 1961 model produced 325 hp (242 kW) and 435 ft·lbf (589 N·m), while the 10.25:1 1962-1964 version upped power to 330 hp (246 kW) and 440 ft·lbf (596 N·m). A special 1963 10.5:1 version was also produced with 345 hp (257 kW).
The 1964 Starfire produced 345 hp (257 kW) and 440 ft·lbf (596 N·m) for the 1964 98 Custom-Sports Coupe. It was optional on 1964 98s and Super 88s.
From 1961 to 1963 Oldsmobile manufactured its own version of the Buick-designed, all-aluminum 215 engine for the F-85 compact, known as the Rockette. This was a compact, lightweight engine with a dry weight of only 350 lb (159 kg). The Oldsmobile engine was very similar to the Buick engine, but not identical: it had larger combustion chambers with flat-topped (rather than domed) pistons, six bolts rather than five per cylinder head, and slighly larger intake valves. With an 8.75:1 compression ratio and a two-barrel carburetor, the Olds 215 had the same rated hp, 155 hp @ 4800 rpm, as the Buick 215, with 220 ft·lbf of torque at 2400 rpm. With a four-barrel carburetor and 10.25:1 compression, the Olds 215 made 185 hp (138 kW) @ 4800 rpm and 230 ft·lbf (312 N·m) (@ 3200 rpm.
The basic Buick/Olds 215 V8 went onto become the well known Rover V8, remaining in production until the 1990s.
In 1962 and 1963 Oldsmobile built a turbocharged version of the 215. The small-diameter turbocharger was manufactured by Garrett AiResearch and produced a maximum of 5 lb (0.34 bar) boost at 2200 rpm. The engine had 10.25:1 compression and a single-barrel carburetor. It was rated at 215 hp (160 kW) @ 4600 rpm and 300 ft·lbf (406 N·m) @ 3200 rpm. The high compression ratio created a serious problem with spark knock on hard throttle applications, which led Olds to use a novel water-injection system that sprayed small amounts of distilled water and methyl alcohol (dubbed "Turbo-Rocket Fluid") into the combustion chambers to cool the intake charge. If the fluid reservoir was empty, the engine's timing would be retarded to avoid engine damage. Unfortunately, many customers did not keep the reservoir filled, or had mechanical problems with the turbocharger plumbing.
The turbocharger was offered only in a special Jetfire model, which was the first turbocharged passenger car offered for public sale. Only 9,607 were sold in two model years, and many were converted by dealers to conventional four-barrel carbureted form.
The second generation of Oldsmobile V8s was produced from 1964 through 1990. Most of these engines were very similar, using the same bore centers, although "big-block" versions were produced with a 10.625 in (269.9 mm) deck height rather than 9.33 in (237 mm). Big-block and Diesel versions also used a larger 3.0 in (76.2 mm) instead of 2.5 in (63.5 mm) main journal for increased strength. All generation-2 small-block Olds V8s use a stroke of 3.385 in (86 mm), and all but one big-block use 4.25 in (107.9 mm).
These engines, while being a wedge-head, had 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.
The first second-generation Olds V8 was the 1964 330 in³ (5.4 L). It introduced the standard 3.385 in (86 mm) stroke and used a 3.938 in (100 mm) bore and was produced through 1967. 330s were painted gold and had forged steel crankshafts. While the 4 barrel versions had a harmonic balancer, the 2 barrel versions had only a hub.
For 1967, a 330 in³ (5.4 L) Jetfire Rocket was produced.
1965 through 1967 Early 400s used a slightly over-square 4.0 in (101.6 mm) bore and 3.98 in (101.1 mm) stroke. This was the desirable 400.
1968 and 1969 400s shared the Olds big-block standard 4.25 in (107.9 mm) stroke with the 455 but used a very undersquare 3.87 in (98.3 mm) bore to comply with GM's displacement restrictions in the A-body cars and reduce tooling costs. This was the less desirable Later 400. Early 400's used the same forged steel crankshaft as the 425's, while the Later 400's used the same cast iron crankshaft of the 455's.
All 400s were painted bronze.
The 1967 4-4-2 Rocket was a 400 in³ (6.6 L) V8.
The 425 in³ (7.0 L) big-block was the first tall-deck, "big block" produced from 1965 through 1967. It is arguably the best engine Olds made in the musclecar era, although it never made it into a "musclecar". It used a 4.126 in (104.8 mm) bore and 3.975 in (101 mm) stroke. Most 425s were painted red. All 425 engines had forged steel crankshafts with harmonic balancers.
The standard 1965-1967 425 in³ (7.0 L) was called the Super Rocket. Which was the most powerful engine option for the Oldsmobile 88 & 98 of 1965 through 1967. Compression ratios of 9 to 1 or 10.25 to 1 were available in the U.S.
A special 1965-1967 425 in³ (7.0 L) 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. It shared the same compression ratio of the Toronado Rocket at 10.5 to 1. It also used the .921 in lifter bore size of the Toronado Rocket.
Another 1967 425 in³ (7.0 L) was the Ultra High Compression Toronado Rocket. Unlike all other 425s, this version was painted slate blue metallic. The Toronado 425 engines had the same .921 in (23.4 mm) diameter lifters of the first-generation Oldsmobile engines rather than the standard .842 in (21.4 mm). This let the engineers increase the ramp speed of the camshaft for more power, 385 hp (287 kW), without sacrificing idle or reliability.
A larger big-block was introduced for 1968 as the Rocket 455 at 455 in³ (7.5 L) to replace the 425s. It kept the 425's 4.126 in (104.8 mm) bore and bumped the stroke to 4.25 in (107.9 mm). 1968-1969 455s were painted red, while 1970-1976 versions were metallic 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. Output ranged from 210 to 400 hp (156 to 298 kW).
Produced from 1968 through 1980, the Rocket 350 was entirely different from the other GM divsions 350's. It used a 4.057 in (103 mm) bore and Oldsmobile small-block standard 3.385 in (86 mm) stroke for 350 in³ (5.7 L). 1968-1974 350s were painted gold, while 1975-1980 models were metallic blue, at which time the "Rocket" name disappeared from the air cleaner decal. Output ranged from 160 to 320 hp (119 to 238 kW). All Oldsmobile 350 engines had cast-iron crankshafts with harmonic balancers.
The Oldsmobile 350 was also produced with an electronic port fuel injection system, introduced in the Cadillac Seville of 1976.
Oldsmobile's own L34 350 in³ (5.7 L) V8 was used in the 1976-1980 Hurst/Olds models. The L34 used a 4-barrel carburetor.
The LF9 was a Diesel version of the 350 in³ (5.7 L) V8. It was produced from 1978 to 1985 and was used by most domestic GM marques. 1980-1985 versions used roller lifters. These engines were notably unreliable, a situation detailed below, and at the Oldsmobile Diesel V6 engine page.
Despite the fact that these engines looked in large part like their gasoline cousins, they were indeed quite different. The castings were much thicker and heavier, and a higher quality alloy was used for the block and heads. The main bearing journals were also increased to 3.000 inches in size to compensate for the higher operating stresses and pressures that diesels exert on their reciprocating parts. The primary problem with GM's Diesel engines of the 1970s was due in large part to poor fuel quality (diesel fuel was notoriously filthy and contaminated with water in the late 1970's), which caused corrosion in the fuel injection pump. This corrosion could (and often did) cause an incorrect injection cycle, which would produce abnormally high cylinder pressures. This in turn would cause the cylinder head to "lift" up off of the block, and stretch (or even break) the head bolts. Once the head gasket was compromised, the gasket would leak coolant into the cylinder. At 22.5:1 compression, there was little volume left in the cylinder at TDC. The uncompressible quality of liquids means that the engine would hydro lock, breaking pistons, crankshafts, connecting rods, and other parts, resulting in complete and catastrophic engine damage. Why then, did other Diesel engines, from GM and other companies, not have these problems? The answer lies in the lack of an effective water separating system, such as can be found on other diesel applications. Overall, the main ingredients of disaster that affected this engine lie in:1) A poorly designed fuel system, which was fostered by a desire to insulate the consumer from the unpleasant aspects of Diesel ownership. 2) A misguided attempt to market the diesel engine as if it was as convenient to operate and maintain as a gasoline engine. 3) A poorly trained service staff which often used the incorrect oils and service procedures for this (and any, for that matter) Diesel engine. These factors combined to create the ultimate downfall of this engine. In the hands of an experienced diesel operator, these engines can (and often do) travel for hundreds of thousands of trouble free miles. However, for a society of people who just "gas and go", this engine was particularly ill suited to the task.
The 455 big-block Olds V8 was replaced in 1977 with the 403 in³ (6.6 L). It used a wide 4.351 in (110.5 mm) bore, the largest ever used in a small-block V8, with the Olds small-block standard deck and 3.385 in (86 mm) stroke. The bore was so wide that it was "siamesed" (similar to the Chevrolet 400 small block motor) — there was no space for coolant flow between the cylinders. This sometimes led to overheating problems. Like the 455, it was painted metallic blue.
The Olds 403 was used by Buick and Pontiac in addition to Oldsmobile. The engine was only produced through 1979. Output was 185 hp (137 kW) and 320 ft·lbf (433 N·m).
A smaller 260 in³ (4.3 L) V8 was produced in 1975 by decreasing the bore to just 3.5 in (88.9 mm). This was the first powerplant to use the Rochester Dualjet carburetor; however, the 260 was not high powered. No 260s had 4-barrel carburetors. Production of the 260 V8 ended in 1982 when the 307 became the only gasoline V8 engine in Oldsmobile's line.
The 260 engine was designed for economy and it was the first engine option above the 3.8 V6 Buick engine that had been made standard in many Oldmobile models by the late 1970's. While the 260 engines were not very powerful compared to the larger 350 and 403 V8 engines, 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 unreliable Turbo Hydramatic 200 transmission as opposed to the THM350 coupled behind the Buick 3.8. A 5-speed manual transmission was also available with some 260-equipped vehicles.
The LV8 was a 260 in³ (4.3 L) version produced from 1975 to 1982. It produced just 105 hp (78 kW) and 205 ft·lbf (283 N·m).
The LF7 was a Diesel version of the 260 in³ (4.3 L) V8 produced in 1979 and 1980. Output was just 90 hp (67 kW) and 170 ft·lbf (230 N·m). These engines were notably unreliable, a situation detailed at the Oldsmobile Diesel V6 engine page.
A slightly larger 307 in³ (5 L) version was introduced in 1980. It uses the Oldsmobile 3.385 in (86 mm) stroke and a 3800-like 3.8 in (96.5 mm) bore. All 307s were painted black. It was used in most Oldsmobile models, as well as those from Buick, Cadillac, Chevrolet, and Pontiac. Every 307 was carbureted, and all used 4-barrel carbs. In fact, the 1990 5.0 L Olds V8 was the last carbureted passenger car engine on the market in the United States (excluding the 1991 Ford LTD Crown Victoria Police Interceptor 351 in³ and the 1994 Mazda pick up truck, the very last carbureted road use vehicle sold in the US).
Oldsmobile used the popular LV2, a 307 in³ (5.0 L) engine, from 1980 to 1990. It was used by every domestic GM automobile marque. Roller lifters were added in 1985.
There were two versions, the standard Y version produced just 140 hp to 150 hp (104 to 111 kW). The high-output 9 version was available in the 1983 and 1984 Hurst/Olds & 442. All LV2s feature a 4-barrel carburetor.
The LG8 was a modern 307 in³ 5.0 L High-Output derivative of the LV2 produced from 1985 to 1987. Performance modifications included improved intake and a "hot" camshaft. It was offered in the 442 version of the Oldsmobile Cutlass Supreme. Output for the first year was 180 hp (134 kW) and 245 ft·lbf (318 N·m). The addition of roller lifters for 1986 increased torque to 255 ft·lbf (332 N·m), while lowering the RPM at which peak horsepower and torque was achieved via a change in head design.
The Oldsmobile V8 ended production in 1990. The company later introduced a new vehicle, the Oldsmobile Aurora, with a new generation of V8 power. Based on the Cadillac Northstar engine, the Oldsmobile Aurora engine was a DOHC design.