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1955-1957 Pontiac Strato-Streak

Pontiac's Division

It was General Motors' custom, in the 1950s, to permit the division responsible for any important new development to enjoy exclusive rights to it for the first year -- in this case, Pontiac's division.

The innovative new 1955 drive train made Pontiac's division the envy of General Motors.
The innovative new drive train made
Pontiac's division the envy of General Motors.

Ed Cole, however, sought permission to use Leach's design from the very beginning. We do not know what powers of persuasion may have been applied to Robert M. Critchfield, who had been Pontiac's general manager since 1952, though it's common knowledge that Cole -- who would eventually become president of General Motors -- enjoyed considerable clout in the front office. In any case, Ed Cole's request was granted.

Pontiac's new engine block, like its valve train, was relatively light. This was due in part to the engineers' use of precision casting techniques. But more importantly, in lieu of the deep-block design then in general use (exemplified by Ford's widely touted "Y-Block" V-8), Pontiac split the block at the crankshaft centerline. Thanks to the engine's basic rigidity, this was done with no sacrifice in strength.

Other features of the new V-8 included the right cylinder bank cast slightly forward of the left to simplify distributor positioning, a forged steel crankshaft cradled in five large main bearings, completely machined combustion chambers, and a "Quad-Gallery Lubrication System" to keep "every highly machined part cushioned with oil." Hydraulic valve lifters were also featured.

"Where mechanical connections were used before," said Pontiac, "the Strato-Streak V-8 uses a column of oil to compensate for dimensional changes caused by heat-expansion of valve train parts. The quantity of oil needed is adjusted -- automatically -- to keep lifters in constant contact with push rods. The result? Accurate timing, silent operation, long valve life, no tappet adjustment ever needed!"

Standard issue was a three-speed, column-mounted manual gearbox. Cars so-equipped were powered by a regular-fuel, 173-horsepower version of the Strato-Streak V-8, carrying a compression ratio of 7.40:1. But nearly 91 percent of all 1955 Pontiacs left the factory equipped with the four-speed Dual-Range Hydra-Matic transmission, a $178 option, supplied in combination with 8.00:1 heads. In this edition, the V-8 generated 180 horses.

Then, in the spring, a $35 Power Pack became available. With a four-barrel carburetor replacing the standard two-barrel pot, this package raised the gross horsepower to a comparatively lusty 200, just two horses less than Oldsmobile's Super 88.

Altogether, 13 models were offered, four each in the Chieftain "860" Special and "870" Deluxe series, and five Star Chiefs, including a spectacular hardtop-style, two-door station wagon called the Safari. The Chieftains rode a wheelbase of 122 inches, while top-of-the-line Star Chiefs (except for the Safari) employed a 124-inch chassis.

Overall, the 210.2-inch-long Star Chiefs (again, apart from the Safari) stretched seven inches longer than the Chieftains, the difference taking the form of an extended rear deck. As a matter of fact, the 1954 Star Chief had even more rear overhang, resulting in an overall length 3.5 inches greater than that of the 1955 version; some owners had complained that turning into a steep driveway caused the rear bumper to scrape the pavement.

The volume leader in both Chieftair lines, which differed mainly in interior appointments, was the traditional four door sedan, with the smartly styled Catalina two-door hardtop in second place in the 870 line. A two-door sedan and four-door station wagon completed the roster in each instance, save for a lone two-door wagon in the 860 series.

The Star Chief four-door sedan and Catalina hardtop came in either deluxe or Custom trim; the Star Chief convertible, Pontiac's only ragtop, was considered a deluxe. The Safari, Pontiac's most expensive model at $2,962, was a member of the Star Chief Custom sub-series despite its shorter wheelbase and length. But the most popular Pontiac of them all for 1955 was the $2,499 Star Chief Custom Catalina.

Overall, the new Pontiacs represented the most radical change the division had seen since 1933, and sales responded accordingly. It is true, of course, that 1955 was a record year for the entire industry. Sister divisions Buick and Oldsmobile, for example, scored 47- and 48-percent production gains, respectively. Pontiac, though it remained in sixth place, did even better, showing a rousing 57-percent increase!

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