The term Cadillac V8 may refer to any of a number of V8 engines produced by the Cadillac division of General Motors since it pioneered the first such mass-produced engine in 1914.
Most commonly, such a reference is to one of the manufacturer's most successful, best known, or longest-lived 90° V8 engine series. These include the pioneering overhead valve cu in introduced in 1949, made in three displacements up to ; a introduced in 1963 that grew to ; and a introduced in 1968 and enlarged to . Also notable was the Northstar, which debuted in 1992 as a 4.6 litre, and was also produced in 4.4 L and 4.2 L versions.
When the Northstar engine series ended production in 2010, it became the last General Motors division to retain its own proprietary V8 design. This changed when Cadillac created the twin-turbo "Blackwing" engine in 2019.
L-head
The Type 51 was the first Cadillac V8. Introduced in 1914, it was the standard engine for 1915 Cadillac models. It was a 90° design with an L-head (sidevalve) configuration and was water-cooled. Bore and stroke was , for a total of of displacement. Output was .
This engine was designed under the leadership of Cadillac's chief engineer (1914–1917), Scottish-born D (D'Orsay) McCall White (1880 -), later a vice president of Cadillac. Hired by Henry Leland for his V-engine expertise from his employment as chief engineer at Napier, and previously Daimler at Coventry, he was later to move to Nash with LaFayette. White was appointed to a committee of three to supervise the development of the V12 Liberty aircraft motor, that later contributed to cross town rival Lincoln Motor Company introducing the Lincoln L series much later in 1917.
The engine was refined for 1923 with a crossplane crankshaft that introduced the (now standard) 90° offset for each pair of cylinders which improved balance and smoothness. Power was up to .
The L-head was on the Ward's 10 Best Engines of the 20th century list.
L-head applications: Cadillac Type 51 Cadillac Type 53 Cadillac Type 55 Cadillac Type 57 Cadillac Type 59 Cadillac Type 61 Cadillac V-63 Cadillac Series 341 Oldsmobile Light Eight
Cadillac created a new V8, the 341, for 1928. It was a engine and produced . The same year saw the introduction of the synchromesh transmission. This engine was used in the Series 341 and 341B cars of 1928 and 1929.
From 1930 through 1935, Cadillac produced a version with an increased displacement of . This used a bore and stroke. This engine was used in the Cadillac Series 353 and Series 355.
Monobloc A "monobloc engine" was used in the 1936 Series 60. It was designed to be the company's next-generation powerplant at reduced cost from the 353 and Cadillac V12. The monobloc's cylinders and crankcase were cast as a single unit, and it used hydraulic valve lifters for durability. This design allowed the creation of the mid-priced Series 60 line.
Bore and stroke was . This engine was closely related to a monobloc design earlier introduced in the 1936–1948 engine, which was modified with a bore. This was used in the Series 60/60S/61/62/63/65/67 and 70/72/75. It was also used in a dual setup in tanks (e.g. M5 Stuart and the M24 Chaffee), in World War II mated to a Hydramatic transmission.
LaSalle
In 1937, the new monobloc flathead gained in Cadillac V-8 models to , while the LaSalle straight-8 of 1934–1936 that originated from Oldsmobile actually was replaced with the 1936 smaller version at . In 1941, the LaSalle nameplate was phased out along with the , and Cadillacs, all powered, were available with the new Hydramatic automatic transmission which debuted in Oldsmobile the previous year. These engines were produced through 1948.
OHV
331 series For 1949, Cadillac and Oldsmobile each produced their V8 designs (the Oldsmobile engine was the 303). Both of the engines were overhead valve designs, pioneered by Buick. The Cadillac 331 engine featured a "dry" (coolant exited through an assembly attached directly to the cylinder heads), open runner (requiring the use of a tappet valve cover) intake manifold, rear-mounted distributor, and shaft-mounted rockers. Crankshaft end play is carried by the rear bearing on the two GM engines. It has the lighter "skirtless" block where the oil pan flange does not descend appreciably below the crankshaft centerline and they both have a partial integral cast iron clutch housing that compares to the early Chrysler Hemi V8 design. 1955 331 engines went to a lighter "flat back" that bolted to a clutch and flywheel housing at the front of the transmission.
Bore and stroke are for an overall displacement of . This engine features an oiling system which uses a central cast-in passage between the lifter galleries feeding oil to the cam and crank by grooves machined into the cam bores. A single drilled passage per bearing saddle feeds both cam and crank journals. Shared with the Oldsmobile Rocket V8 is how the lifters are supplied oil through small "bleeds" instead of placing the lifters directly into the right and left side oil supply galleries. Many early racers would replace the Cadillac hydraulic lifter and rocker assemblies with the solid lifters and adjustable rockers from the Studebaker V8 for operation at higher engine speeds.
365 Displacement was increased to for 1956 by increasing the bore to while maintaining the stroke. For the three years that the 365 was made, the base versions had a single four-barrel carburetor. The 1956 version produced 285 horsepower. The 1957 version raised that base engine output to 300 horsepower, while the 1958 base version cranked out 310. Eldorados featured multi-carb engines in all 3 years. The Eldorado engines were also optional on all other Cadillacs. The 1958 Eldorado 3-2bbl version produced .
390 A longer, stroke pushed displacement to for 1959, yielding , while the Eldorado Tri-power reached .
390 series
For the 1963 model year, Cadillac redesigned its V8 engine, modernizing the tooling used in the production line while optimizing the engine's design. Although it shared the same layout and architecture with the 1949-vintage engine, the revised engine had shorter connecting rods and was lower, narrower, and shorter. The accessories (water pump, power steering pump, distributor) mounted on a die-cast aluminum housing at the front of the engine for improved accessibility. An alternator replaced the former generator. The crankshaft was cored out to make it both lighter and stronger. The revised engine was lighter than its predecessor, for a total dry weight of .
The revised engine shared the same bore and stroke of its predecessor, for an unchanged displacement of . Power was unchanged at , as was torque at .
429 For 1964, the engine had a bore and stroke, raising displacement to . Power rose to and torque to . It also included its first emission control system, which was a positive crankcase ventilation unit. The 429 was used through the 1967 model year.
472 series Cadillac introduced an all-new engine for 1968. Although the modernized 390 series engine was compact and light for its displacement and output, represented the limit of the original architecture's expansion, and it had been surpassed by Chrysler's 440 and Lincoln's 462 and 460. Cadillac went bigger, with provision for even more expansion.
At introduction, the new engine had a bore and stroke for a displacement of . "Extensively redesigned" to ease maintenance, it used 10% fewer parts and 25% fewer gasketed joints as before. It delivered at 4400 rpm and a massive torque at just 3000 rpm. The new engine was about heavier than its predecessor. It was used through 1974. It was designed with potential for a displacement.
500
For 1970, Cadillac fitted a crankshaft with a stroke, increasing total displacement on the engine to . At its introduction it was rated at , SAE gross, and of torque. For 1971, compression was reduced from 10.0:1 to 8.5:1, the lowered compression ratio dropped the 500's gross output from to , or in the new SAE net ratings. By 1976, its final year, it had fallen to . However, a new Bendix electronic fuel injection system was offered as an option, and it increased power output to . The 500 was exclusive to the Eldorado.
Year Engine VIN code Engine letter code Displacement Rated horsepower Rated torque Bore x stroke Compression ratio Oil pressure1968–1969NoneNoneat 4400 rpm at 3000 rpm10.5:11970 (SAE gross)10.0:1 at 4400 rpm at 3000 rpm1971 (SAE gross)R61E,Q at 4400 rpm at 2800 rpm8.5:1S at 4400 rpm at 2800 rpm1972 (SAE net)R62E,Q at 4400 rpm at 2400 rpmS at 4400 rpm at 2400 rpm1973R63E,Q at 4400 rpm at 2400 rpmS at 4400 rpm at 2400 rpm1974R64E,Q at 4400 rpm at 2400 rpmSat 3600 rpm at 2000 rpm197565E,Q197666E,Q at 3600 rpm at 2000 rpm
425 series Starting in the mid to late 1970s, Cadillac expanded its product range, offering more mid-sized vehicles. For example, while the Cadillac Seville initially used a variant of the Oldsmobile gasoline V8, Cadillac also began work on its own proprietary engines.
In 1977, Cadillac introduced a new V8, based on the architecture of the 472, but with a smaller, bore and the same stroke. The new engine was also lighter.
The 425 was offered in L33 form, with a four-barrel carburetor, producing at 4000 rpm and of torque at 2000 rpm, and L35 with electronic multi-port fuel injection for and of torque, but peaked at 2400 rpm.
The 425 was used through 1979 on all Cadillacs except the Seville and 1979 Eldorados.
368 In 1980, the 425 was replaced with the L61, which was the same basic 472 family engine de-bored to but retaining the 472 and 425 engines' stroke for a total displacement of . The reduction in displacement was largely an effort to meet CAFE requirements for fuel economy. Throttle-body fuel injection was now standard on Eldorado and Seville when equipped with the 368. Rear-wheel-drive cars and the Commercial Chassis for hearse and ambulance builders used the Rochester Quadrajet 4-barrel carburetor.
Cadillac referred to this new TBI (throttle-body fuel injection) system as Digital Fuel Injection (DFI); this particular induction system was later adopted by other GM divisions, except on Oldsmobile V8s, and was used well into the mid-1990s on GM trucks.
Power output dropped to at 3600 rpm and torque to at 2000 rpm in DEFI forms as used on the front-wheel-drive Seville and Eldorado but on the four-barrel Quadrajet-equipped RWD models. This engine was standard on all Cadillacs except the redesigned Seville, in which it was optional.
V8-6-4
For 1981, Cadillac introduced a new engine that would become notorious for its unreliable electronics, the V8-6-4 (L62). The L61 had not provided a significant improvement in the company's CAFE numbers, so Cadillac and Eaton Corporation devised a cylinder deactivation system called Modulated Displacement that would shut off two or four cylinders in low-load conditions such as highway cruising, then reactivate them when more power was needed. When deactivated, solenoids mounted to those cylinders' rocker arm studs would disengage the fulcrums, allowing the rockers to "float" and leave the valves closed despite the continued action of the pushrods. These engines are easily identified by their rocker covers, which each have elevated sections over two cylinders with electrical connectors on top. With the valves closed, the cylinders acted as air springs, which both eliminated the feel of "missing" and kept the cylinders warm for instant combustion upon reactivation. Simultaneously, the engine control module would reduce the amount of fuel metered through the TBI unit. On the dashboard, an "MPG Sentinel" digital display could show the number of cylinders in operation, average or current fuel consumption (in miles per gallon), or estimated range based on the amount of fuel remaining in the tank and the average efficiency since the last reset.