The Pontiac straight-8 engine is an inline eight-cylinder automobile engine produced by

Pontiac Pontiac may refer to: *Pontiac (automobile), a car brand *Pontiac (Ottawa leader) ( – 1769), a Native American war chief Places and jurisdictions Canada * Pontiac, Quebec, a municipality **Apostolic Vicariate of Pontiac, now the Roman Catholic D ...

from 1933 to 1954. Introduced in the fall of 1932 for the 1933 models, it was Pontiac's most powerful engine at the time and the least expensive eight-cylinder engine built by an American automotive manufacturer. During its 21-year run displacement of the "eight" increased twice as platforms grew. It was superseded by Pontiac's new V8, the

287 Year 287 (Roman numerals, CCLXXXVII) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. In the Roman Empire, it was known as the Year of the Consulship of Diocletian and Maximian (or, less frequ ...

, in 1955. Engine block and cylinder heads were cast at

Saginaw Metal Casting Operations Saginaw Metal Casting Operations is an automobile engine foundry plant in Saginaw, Michigan. Opened under GM management in 1919, the factory produces engine blocks and cylinder heads for General Motors vehicles. The factory currently occupies 1.9 ...

then assembled at

Tonawanda Engine Tonawanda Engine is a General Motors engine factory in Buffalo, New York. The plant consists of three facilities totaling and sits upon . The factory receives cast engine blocks from Defiance Foundry in Defiance, Ohio and Saginaw Metal Casting Op ...

before delivery to

Pontiac Assembly Pontiac Assembly was one of four General Motors assembly plants in Pontiac, Michigan located along Baldwin Avenue. It served as the home factory for GM's Pontiac Motor Division since it was built in 1927. It was across the street from the curren ...

for installation.

History

The straight-8 was dubbed the ''Silver-Streak'' at Pontiac Division. Powered by the "eight", optional in lower-end models, a Pontiac was promoted as a likable automobile, with enough

power Power most often refers to: * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power * Power (social and political), the ability to influence people or events ** Abusive power Power may a ...

under the hood to get the job done in affordable luxury. However, by the early 1950s, powerful

overhead valve An overhead valve (OHV) engine, sometimes called a ''pushrod engine'', is a piston engine whose valves are located in the cylinder head above the combustion chamber. This contrasts with earlier flathead engines, where the valves were located be ...

V8s from sister GM Divisions

Cadillac The Cadillac Motor Car Division () is a division of the American automobile manufacturer General Motors (GM) that designs and builds luxury vehicles. Its major markets are the United States, Canada, and China. Cadillac models are distributed i ...

Buick Buick () is a division of the American automobile manufacturer General Motors (GM). Started by automotive pioneer David Dunbar Buick in 1899, it was among the first American marques of automobiles, and was the company that established General ...

and

Oldsmobile Oldsmobile or formally the Oldsmobile Division of General Motors was a brand of American automobiles, produced for most of its existence by General Motors. Originally established as "Olds Motor Vehicle Company" by Ransom E. Olds in 1897, it produ ...

, as well as new overhead valve V8s from

Ford Motor Company Ford Motor Company (commonly known as Ford) is an American multinational automobile manufacturer headquartered in Dearborn, Michigan, United States. It was founded by Henry Ford and incorporated on June 16, 1903. The company sells automobi ...

and

Chrysler Corporation Stellantis North America (officially FCA US and formerly Chrysler ()) is one of the " Big Three" automobile manufacturers in the United States, headquartered in Auburn Hills, Michigan. It is the American subsidiary of the multinational automoti ...

, made the flathead "Silver Streak" all but obsolete. It was a quiet, smooth running, cheap to produce engine that served the needs of the 1930s and '40s Pontiac buyers adequately for power. By 1953 the Strato Streak V8 was ready to go, with Pontiac chassis and steering already adapted for it, but it was held back by the protesting Buick and Olds divisions. It was a truly modern, durable but affordable design perfectly matched to Pontiac's target market. A few years later (fall of 1956), under the guidance of Bunkie Knudsen Pontiac was determined to change its image into a performance car to boost sales, this led Knudsen to look for further talent, including Pete Estes as chief engineer (taken from Olds division) and

John DeLorean John Zachary DeLorean (January 6, 1925 – March 19, 2005) was an American engineer, inventor, and executive in the U.S. automobile industry, widely known for his work at General Motors and as founder of the DeLorean Motor Company. DeLorean mana ...

as director of advanced engineering, a former

Packard Packard or Packard Motor Car Company was an American luxury automobile company located in Detroit, Michigan. The first Packard automobiles were produced in 1899, and the last Packards were built in South Bend, Indiana in 1958. One of the "Thr ...

and Chrysler engineer. Pontiac became known as a performance division based upon the durable, well performing V8s that came later, all of them based upon the original 287 of 1955.

Market

Designed and priced for conservative lower middle class buyers, the Pontiacs filled a slot between the popular

Chevrolet Chevrolet ( ), colloquially referred to as Chevy and formally the Chevrolet Motor Division of General Motors Company, is an American automobile division of the American manufacturer General Motors (GM). Louis Chevrolet (1878–1941) and ous ...

and the higher priced

s and

Design

The "eight" was a typical American built engine for its time, a side-valve L-head, or "flathead", with a

chain drive Chain drive is a way of transmitting mechanical power from one place to another. It is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles. It is also used in a wide variety of machines besides vehicles. ...

n cam. It was

naturally aspirated Naturally may refer to: ;Albums * ''Naturally!'', an album by Nat Adderley * ''Naturally'' (Houston Person album) * ''Naturally'' (J. J. Cale album) * ''Naturally'' (John Pizzarelli album) * ''Naturally'' (Sharon Jones album) * ''Naturally'' ...

through a

Carter Carter(s), or Carter's, Tha Carter, or The Carter(s), may refer to: Geography United States * Carter, Arkansas, an unincorporated community * Carter, Mississippi, an unincorporated community * Carter, Montana, a census-designated place * Carter, ...

"W" series single or dual-venturi (one- or two-barrel) downdraft

carburetor A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meteri ...

Advantages

Of all cylinder layouts without balance shaft, a straight eight design has very low inherent vibration, while the side-valve layout contains the moving parts of the valve train within the cast-iron block, enabling it to be very quiet compared to an overhead valve configuration (as in the contemporary

engines). Combined with a substantial exhaust manifold and effective intake and exhaust muffling this can lead to a very quiet vehicle, both internally and externally. At the time of its use, a quiet and vibration free engine was thought to be a mark of quality in an automobile. Bores need be of small diameter to keep the engine length down, and so strokes must be long to obtain larger displacements — such configurations (called "undersquare") exhibit good low-rpm torque and are capable of slow idle speeds, enhancing both drivability and quietness. While

Chrysler Stellantis North America (officially FCA US and formerly Chrysler ()) is one of the " Big Three" automobile manufacturers in the United States, headquartered in Auburn Hills, Michigan. It is the American subsidiary of the multinational automoti ...

vehicles had similar engines they were not targeted for the lower middle price range enabled by General Motors' manufacturing expertise and volumes of the time.

Disadvantages

As with other iron block straight configurations, the engine is considerably heavier than an equivalent V configuration, requiring more materials for the crank and crankcase and so increasing overall vehicle weight in even greater proportion. The long crankshaft tends to exhibit torsional vibration modes under high power, while side-valve flathead engines inhibit smooth intake and exhaust gas flow, limiting power. None of these disadvantages were disabling until the "horsepower race" initiated in the early 1950s ensured the dominance of the overhead valve V8.

Applications

During its run, the eight came in all Pontiacs, which included the ''Special'' and ''Deluxe'' (1936–40), ''Torpedo'' (1940–48) and ''Streamliner'' (1942–52), as well as the first six years of the ''

Chieftain A tribal chief or chieftain is the leader of a tribe, tribal society or chiefdom. Tribe The concept of tribe is a broadly applied concept, based on tribal concepts of societies of western Afroeurasia. Tribal societies are sometimes categori ...

'' (1949–58) and the debut year for the '' Star Chief'' (1954–66).

Specifications

Compression Compression may refer to: Physical science *Compression (physics), size reduction due to forces *Compression member, a structural element such as a column *Compressibility, susceptibility to compression *Gas compression *Compression ratio, of a c ...

on the "eight" started at 5.7:1 initially,Pontiac sales brochure, Pontiac Motor Division, 1933. and was increased to 6.2:1 in 1934.Pontiac Shop Manual 1934 Models General Motors of Canada In 1940 it was increased again to 6.5:1. From 1952 to 1954 two compression ratios were specified, 6.8:1 with

syncromesh A manual transmission (MT), also known as manual gearbox, standard transmission (in Canada, the United Kingdom, and the United States), or stick shift (in the United States), is a multi-speed motor vehicle transmission system, where gear changes ...

(manual) transmission, and 7.7:1 with

Hydramatic Hydramatic (also known as Hydra-Matic) is an automatic transmission developed by both General Motors' Cadillac and Oldsmobile divisions. Introduced in 1939 for the 1940 model year vehicles, the ''Hydramatic'' was the first mass-produced fully-a ...

automatic transmission An automatic transmission (sometimes abbreviated to auto or AT) is a multi-speed transmission used in internal combustion engine-based motor vehicles that does not require any input from the driver to change forward gears under normal driving c ...

.Motor's Auto Repair Manual, Sixteenth Edition, Motor.,1953. The engine had a remarkably low idle speed of 450 rpm with standard transmission and 375 rpm (while in drive) for the automatic; a modern engine is usually tuned to a minimum 600-700 rpm. The electrical system was a 6-volt primary with a negative ground, and a conventional mechanical ignition, with the

firing order The firing order of an internal combustion engine is the sequence of ignition for the cylinders. In a spark ignition (e.g. gasoline/petrol) engine, the firing order corresponds to the order in which the spark plugs are operated. In a diesel engi ...

1-6-2-5-8-3-7-4. The Pontiac engines employed a full pressure oiling system and full bearing inserts, unlike its Chevrolet cousin. Below are specifications as per the model year and displacement, with output shown as horsepower (kilowatts).

"Special"-8

At the General Motors

Motorama The General Motors Motorama was an auto show staged by GM from 1949 to 1961. These automobile extravaganzas were designed to whet public appetite and boost automobile sales with displays of fancy concept cars and other special or halo models. Mo ...

for 1954, Pontiac debuted its all new '' Bonneville Special'', a concept car envisioned by head designer

Harley J. Earl Harley Jarvis Earl (November 22, 1893 – April 10, 1969) was an American automotive designer and business executive. He was the initial designated head of design at General Motors, later becoming vice president, the first top executive ever ...

. The concept was equipped with the "Special"-8, a high output engine that was painted bright red and detailed in chrome. This was a unique configuration for the "eight", installed in the only two ''Specials'' ever made. Similar in appearance only, this was a high compression variant, modified with a high-lift

cam Calmodulin (CaM) (an abbreviation for calcium-modulated protein) is a multifunctional intermediate calcium-binding messenger protein expressed in all eukaryotic cells. It is an intracellular target of the secondary messenger Ca2+, and the bind ...

and fitted with four Carter YH side-draft one-barrel carburetors, the same used in the 1953 Corvette, under open-mesh breathers. Total output was the highest ever for the "eight", rated at , though some estimated it at over . Like the ''Special'', only two were ever made. Note: Pontiac’s new V8 was being considered for use in the ''Special'' but was instead held back by GM marketing. They directed that the straight-eight be used to keep the V8 a secret from consumers for one more year until its debut the following year."Why the Straight-8?, explained in the same interview above.

Footnotes

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