TIMING BELTS GET WIDER USE
Pontiac introduces the world to the revolutionary OHC six.
For decades, most massproduced four- and sixcylinder engines in the worldwide auto market had a common component: the timing belt. A belt timing mechanism between crankshaft and camshaft delivered a quiet, lightweight engineering advance, which brought the efficiency of overhead-cam (OHC) engines to the motoring public.
Belt drive had its start in the 1950s’ Devin-Panhard racing engines and in small-scale production in Europe, but it was a familiar figure—General Motors’ John Z. DeLorean—who had the vision to put it into largescale production in North America for the first time. •
Overhead-cam configuration
had long been seen as the best way to maximize horsepower, but early interfaces between cam and crankshaft using chains or gears were faulty and expensive.
German automaker Hans Glas
was the first to use a timing belt in a production vehicle in its 1004 coupe in 1962. Glas built only a few thousand per year before BMW bought the company in 1966.
Fresh from his Pontiac GTO
triumph, DeLorean wanted to develop a free-revving sixcylinder engine with a European feel. The Pontiac team worked with Uniroyal to design a fiberglass-reinforced belt that would last the life of the engine.
Pontiac’s OHC six found its
way primarily into mainstream Tempests starting in the 1966 model year. Pontiac also offered a high-performance Sprint version with more horsepower. When Pontiac launched its Firebird in 1967, the OHC six was the base engine, with the Sprint package as an option.
The late ’60s was the era of
V-8 power in America—the freerevving six was not a popular choice. The motor lost its patron when DeLorean moved on to lead Chevrolet in 1969, the last model year the engine was offered. However, when Chevrolet’s compact Vega made its debut in 1971, its four-cylinder engine operated with a timing belt.