Editing Pontiac V8 engine (section)

===Development===
By 1949 work on a {{cvt|287|cuin|L|1|adj=on}} OHV V8 had begun, but moved along slowly. When Robert Critchfield took over as general manager in 1952, he launched an ambitious plan to move Pontiac into the upscale, mid-range [[market segment|market]] occupied by [[Oldsmobile]], and that demanded V8 power. A new engine was fast-tracked, its relatively late start allowing it to take advantage of developments proven in the [[Oldsmobile V8 engine|Oldsmobile V8]] and [[Cadillac V8 engine|Cadillac V8]]. As a result, it was remarkably free of teething problems. During 1951–1952, Pontiac had 23 {{cvt|287|cuin|L|1|adj=on}} V8-equipped 1953 model production prototypes running tests on the GM proving grounds. Pontiac had planned to produce their 1953 models with this new V8, but Buick and Chevrolet appealed to GM management and obtained a two-year delay, so Pontiac had to introduce its new V8 for 1955. Buick wanted the delay so that they could be the only GM division to introduce a new V8 engine in 1953, while Chevrolet didn't want to be the only GM division without a V8 engine for 1954.

The main innovation of the Pontiac engine was reverse-flow cooling and the stamped rocker-arm system, which had been devised by Pontiac engineer Clayton Leach in 1948. At the request of [[Ed Cole]], general manager of [[Chevrolet]], the layout was also used by the Chevrolet V8 released in 1955, an exception to the customary GM policy of allowing a division one year of exclusive use of an internally developed advance.

Displacement began at {{Convert|287|cuin|L|1|adj=on}} and grew as large as {{Convert|455|cuin|L|1|adj=on}} by 1970. Pontiac continued to manufacture its own engines, distinct from [[Buick]], [[Cadillac]], [[Chevrolet]], or [[Oldsmobile]], until 1981. Pontiac engines were used in its U.S.-market cars; Canadian-built Pontiac automobiles generally used [[Chevrolet]] engines. From 1955 through 1959, the Pontiac V8 was also used in some [[GMC (General Motors division)|GMC]] [[pick-up truck]]s including the 1958/59 336 cubic-inch versions of the 370CI and 389CI engines. Federal emissions standards and the drive towards "corporate" engines shared among all GM divisions led to the progressive demise of the Pontiac V8 through the late 1970s. The last "true" Pontiac V8s, a {{cvt|265|and|301|cuin|L|1}}, ended production in early 1981.