In January 1930, Cadillac introduced its mighty Sixteen, a bold and extravagant bid for supremacy in the luxury car field. Naturally, the Packard Motor Car Company, the reigning champion of the American luxury market, was not about to take that lying down, and launched its own 12-cylinder Twin Six in 1932. It would be easy to assume the Packard Twin Six was a hastily contrived response to the multicylinder Cadillacs, but that’s only half true. The latter-day Packard Twelve was conceived for quite a different purpose, and therein hangs a tale. This week, we look at the curious history of the legendary Packard V-12 cars with sideways glances at Cord and — the Indianapolis 500? Read on …
THE FIRST PACKARD TWIN SIX
In today’s automotive market, when eight cylinders is considered the ante for most serious luxury cars, it may be disconcerting to think that a hundred years ago, four cylinders was considered a luxury. Packard’s earliest cars had one-cylinder engines, as did early Cadillacs. The development of Packard’s first four, the 1903 Model K, was a matter of some internal controversy; some Packard executives felt the company should concentrate on cheaper one-cylinder runabouts. By 1906, however, Packard had dropped its one- and two-cylinder engines in favor of a T-head inline four of mammoth displacement, initially 350 cu. in. (5,734 cc), soon increased to 432 cu. in. (7,079 cc). This was supplemented in 1909 by the cheaper Model 18, powered by a 266 cu. in. (4,359 cc) four.
Packard apparently contemplated an inline six as early as 1905, although it didn’t go on sale until April 1911. Dubbed “Six” (later “48,” from its taxable horsepower rating), it was again a T-head engine of gargantuan dimensions, some 525 cu. in. (8,601 cc), developing 74 hp (55 kW). A smaller and somewhat cheaper 415 cu. in. (6,796 cc) six, the “38,” followed a year and a half later. This was an L-head (flathead) engine, making 60 hp (45 kW); it sold for about $600 less than its larger brother. (It’s notable as the first Packard engine with an electric starter, which Cadillac had pioneered a year earlier.)
Both sixes were adequately powerful, but Jesse Vincent, who became Packard’s chief engineer in 1912 and VP of engineering in 1915, was not satisfied. Both of Packard’s sixes were huge and to make them bigger — the surest way to produce more power — would make them prohibitive heavy. As it was, their wide bore (4.0 inches/101.2 mm for the 38, 4.5 inches/114.3 mm for the 48) required a long, heavy crankshaft and a massive flywheel. Vincent wanted an engine with a shorter, lighter crankshaft that would allow a large displacement while keeping the swept volume of each cylinder relatively modest for greater smoothness.
Smoothness was a particular concern. In those days, automobile engines were generally bolted directly to the frame; vibration-damping engine mounts were years in the future. One of the attractions of the straight six is its inherent balance — the forces exerted by the pistons and connecting rods cancel each other out, so there’s none of the shake that afflicts inline two-, three-, four-, and five-cylinder engines. Vincent was loath to sacrifice that balance, which led him to eschew the V-8 layout that Cadillac adopted in 1914. A straight eight, meanwhile, would present the same problems of weight and crankshaft size as a bigger six.
The solution, which Vincent pitched to the Packard board in early 1913, was a V-12. Since the V-12 was, as Vincent explained, essentially two straight sixes with a common crankcase, it preserved the six’s inherent balance and smoothness. It also provided comparable displacement while minimizing the swept volume of each cylinder.
That first Packard V-12 engine, dubbed “Twin Six,” displaced 424 cu. in. (6,950 cc). Its cylinder banks were set at a 60-degree angle, providing even firing intervals and making the V-12 narrower than a 90-degree V-8. Like the smaller six of the “38,” the Twin Six was an L-head engine, but it had two camshafts, obviating the need for rocker arms. In the mode of European high-performance engines of its day, it had a narrow bore, only 3.0 inches (76.2 mm), and a long stroke — 5.0 inches (127 mm) — allowing the crankshaft to be shorter, more rigid, and considerably lighter than the six; Packard claimed the Twin Six weighed 400 lb (181 kg) less than the six-cylinder “48.” Despite its smaller displacement, the V-12 was slightly more powerful than the six — 85 hp (63 kW) at 3,000 rpm, compared to 82 hp (61 kW) at 1,720 rpm for the “48” — and had vastly more torque.
The Twin Six was introduced in May 1915 as a 1916 model and immediately became a sensation. Although Packards were too big and too heavy to be considered true performance cars, in July 1915, race car driver Ralph De Palma lapped the Chicago Speedway in a Twin Six touring car at an average speed of 72.7 mph (117.1 km/h), a formidable showing. The V-12 was also adept at that favorite test of prewar motoring, pulling from 3 mph (5 km/h) to top speed in high gear.
The Twin Six sold quite well, doing wonders for Packard’s bottom line; between 1917 and 1919, the company’s annual net profits were around $5.5 million. The Twin Six completely overshadowed the six-cylinder cars, which were discontinued in September 1915, and remained in production through June 1923 with various minor refinements. Packard sold 35,102 Twin Sixes in all, a remarkable total for such an expensive car. (List prices for the 1916 Twin Six had ranged from $2,750 to $4,800 with factory bodywork, roughly $55,000 to $100,000 in 2010 dollars.) The Twin Six also inspired, at least in part, the 12-cylinder “Liberty Engine” used in many Allied aircraft and tanks; Jesse Vincent helped to design the Liberty along with Elbert John Hall of the Hall-Scott Motor Company.
The end of World War I left the European economies in ruins and led to a severe recession in the U.S. Even before the Armistice, Packard president Alvan Macauley decided it would be prudent to offer a smaller, cheaper model. This emerged in September 1920 as the Single Six, powered by a new 242 cu. in. (3,958 cc) L-head six with 52 hp (39 kW). Although the Single Six was a sales disappointment — in part because it still cost a lot more than a V-8 Cadillac — it outsold the costlier Twin Six, whose sales fell from over 5,000 in 1920 to around 1,300 in 1921. By 1922, it was clear the V-12 engine had run its course.
Packard considered developing a new Twin Six, but opted instead for a straight eight, essentially the Single Six engine with two more cylinders and a heavier, nine-bearing crankshaft. The eight initially displaced 358 cu. in. (5,864 cc), but it made 85 hp (63 kW), nearly matching the 90 hp (67 kW) of the final Twin Six. Dubbed “Single Eight,” the new engine replaced the V-12 in the summer of 1923. The Single Eight, renamed simply Eight in 1925, would become Packard’s mainstay for the next decade.
Packard would return to the Twin Six concept seven years later, but the new V-12 engine was planned for a very different market and a very different configuration. If all had gone as planned, it would have become Packard’s first front-wheel-drive car.