Понтиак Рядный Восьмицилиндровый Двигатель: История и Эволюция

The Pontiac straight 8 engine is an inline eight cylinder automobile engine produced by Pontiac 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 It was superseded by Pontiac's new V8, the 287, in 1955. Engine block and cylinder heads were cast at Saginaw Metal Casting Operations then assembled at Tonawanda Engine before delivery to Pontiac Assembly for installation. at Pontiac Division. Powered by the "eight", optional in lower end models, a Pontiac was promoted as a likable automobile, with enough power under the hood to get the job done in affordable luxury. However, by the early 1950s, powerful overhead valve V8s from sister GM Divisions Cadillac, Buick and Oldsmobile, as well as new overhead valve V8s from Ford Motor Company and Chrysler Corporation, 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 as director of advanced engineering, a former Packard 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.

Designed and priced for conservative lower middle class buyers, the Pontiacs filled a slot between the popular Chevrolet and the higher priced Oldsmobiles and Buicks.

The "eight" was a typical American built engine for its time, a side valve L head, or "flathead", with a chain driven cam. It was naturally aspirated through a Carter "W" series single or dual venturi (one or two barrel) downdraft carburetor.

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 Buick 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 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.

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.

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