1962 Buick Special V6; photo by Bill Vance. Click image to enlarge
By Bill Vance
Once shunned as too shaky and quirky to be acceptable, the V6 engine is now one of the most popular engines in the world. Although the vee-type configuration has been around almost as long as the automobile, from V-twin to V16 versions, the idea of a V6 with its odd number of cylinders in each bank was apparently considered too daring. Nordyke and Marmon of Indianapolis experimented with a V6 for their Marmon car in 1905, but returned to more conventional layouts.
The taboo was eventually broken, and once the V6 caught on, its combination of lower weight, compact dimensions and fuel efficiency made it popular with engineers faced with fuel consumption standards and the shrinking underhood space in front-drive cars.
Lancia V6 engine; photo by Wikipedia user Stahlkocher. Click image to enlarge
The first production V6 appeared in the 1950 Italian Lancia Aurelia. It had a 60-degree cylinder bank angle, considered ideal for a V6, and was modern in other ways too with an aluminum cylinder block and heads and hemispherical combustion chambers.
In 1955 General Motors tested the V6 waters by fitting its LaSalle II Motorama concept car with an aluminum, overhead cam, 2.5-litre V6, but it was five years before GM would introduce a production V6. GM’s Truck and Coach Division began offering an overhead valve, 60-degree, 5.0-litre (304.7 cu in.) V6 GMC gasoline truck engine in 1960. It also offered a diesel V6.
The V6 breakthrough in American cars came from Buick in 1962, not as a bold technological statement but as a matter of necessity dictated by economy and packaging needs. They named it the “Fireball” V6, resurrecting a Buick engine name from its straight-eight days.
Following the introduction of the 1960 compact Ford Falcon, Chevrolet Corvair and Chrysler Valiant, larger intermediates came from Buick, Pontiac and Oldsmobile for 1961, the Buick Special, Pontiac Tempest and Oldsmobile F-85.
1962 Buick Fireball V6; photo copyright 2008 Aaron Severson – AteUpWithMotor.com. Click image to enlarge
The Special and F-85 had a Buick-designed, aluminum, overhead valve 3.5-litre (215 cu in.) V8. The standard engine for the Tempest was a 3.2-litre (194.5 cu in.) overhead valve slant four, one half of Pontiac’s big V8. The 3.5 V8 was optional in the Tempest.
After initial teething the aluminum V8 proved a good engine that, after GM sold it, found its way into Rovers, Land Rovers and Morgans. But it was more expensive to build and Buick management wanted its engineers to use a six in the Special.
GM’s existing inline sixes were too long, so engineers experimented by removing two cylinders from the 3.5 V8 and increasing the bore by 3.2 mm (0.125 in.) and stroke by 10.2 mm (0.4 in.) to create a 3.2-litre (198 cu in.) V6. Its cast iron construction was less expensive than aluminum. It was later increased to 3.8 litres (231 cu in.).
The 90-degree V6’s uneven firing sequence was inherently rough running, and although GM masked it for several years using special engine mounts and a heavy flywheel, the demand for smoother operation had to be addressed. Help came with the 1978 Buick V6’s new crankshaft with offset crankpins providing even 120-degree firing. To achieve V8 performance, Buick also offered a turbocharged V6. Further smoothness came with a balance shaft in 1988.
Detroit was finally accepting the V6, and for 1978 Chevrolet removed a couple of cylinders from its small block V8 to produce a 3.3-litre (200 cu in.) 90-degree V6 for its mid-size Malibu and Monza. Then came a new 2.8-litre (173 cu in.) 60-degree V6 for GM’s 1980 X-Cars (Chevrolet Citation, et al.).
Ford used the imported German Ford V6 in the Mercury Bobcat, Ford Pinto and Mustang. It also powered the imported Capri.
In Europe, Volvo-Peugeot-Renault jointly developed an aluminum, overhead cam V6 used in models from the three manufacturers, and sold it to DeLorean.
V6s were used in Formula I Grand Prix racing starting in the 1960s. When turbocharged in the 1970s, they produced prodigious horsepower from 1.5 litres. The Buick V6, in spite of its basic pushrod design was a formidable competition engine when appropriately modified, winning the Indianapolis 500 poll three times.
Now offered by automobile manufacturers world wide, the V6 engine has come a long way in its 60-year history. It is very popular in the family car segment populated by nameplates like Ford Taurus, Chrysler Sebring, Chevrolet Impala, Toyota Camry, Honda Accord and Nissan Maxima, and also in upscale cars like Cadillac, Mercedes-Benz and Audi.