Cadillac V16 engine

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The Cadillac V16 engine was a type of automobile engine produced in the 1930s. Cadillac produced two of only three production, gasoline-fueled V16 engine models in history. Both were used in the Cadillac V-16 automobile, the first from 1930 until 1937, and the second between 1938 and 1940. The company has twice attempted to build a new V16 engine, once in the 1980s and again in recent years, but these have yet to be put into production.

The only other 16-cylinder engines ever attempted were Bugatti's 1915 U16, Marmon's V16, and Cizeta-Moroder's V16. A modern, quad-turbocharged W16 engine was used in the EB 16/4 Veyron built by the new Audi-owned Bugatti in the 1990s. The W16 engine boasts 1001 hp (746 kW), and is the fastest production car on the planet, claiming a top speed of 253 mph (407 km/h).

1 Series 452
2 Series 90
3 V12
4 See also
5 References

[edit] Series 452

With its chief competitor, Packard, already selling a V12 engine against Cadillac's eight-cylinder cars, work began late in the 1920s under Owen Nacker to produce a car of real impact. Lawrence Fisher, Cadillac General Manager, leaked to the press that the company would also build a V12, hoping to keep the real engine secret^[1].

The original Cadillac V16 could be said to be two straight-8 engines on a common crankshaft and crankcase, because each bank operated entirely independently of the other with no other shared components. It used the unusually narrow angle of 45° between the banks to reduce the width of the engine for use in the new Cadillac chassis. The engine was well engineered, with a counterweighted crankshaft (quite a mathematical challenge at the time) and hydraulic valve-lash adjusters.

The 452 V16 had a 3 in (76 mm) bore and a 4 in (102 mm) stroke, giving a displacement of 452 in³ (7.4 L). It was therefore known as the Series 452 engine. Cadillac rated the engine at 185 bhp (138 kW), undoubtedly a somewhat low figure. It was capable of powering these heavy cars to speeds in excess of 80 mph (130 km/h), 100 mph (160 km/h) for some of the lighter examples.

This engine was used in the various V-16 models:

1930-1934 Series 452 ("A" through "C")
1935 Series 60
1936-1937 Series 90

[edit] Series 90

The second generation of V16 used an unusually wide vee-angle of 135°, giving a wide but much lower engine to suit the styling tastes of the late 1930s. The two carburetors, one on each bank, and air cleaners were mounted on top of the engine block in this design. These engines had 'square' proportions; bore and stroke were both 3¼ in (83 mm), giving an overall displacement of 431 in³ (7.0 L). Cadillac rated these engines at the same 185 bhp (138 kW) as the previous series. These engines were known as the Series 90, as were the cars that used them. The Series 90 V16 was produced from 1938 through 1940.

This engine was used in the 1938-1940 Series 90.

The 431 cubic inch displacement 1938-40 Cadillac V16 was one of the last new American auto engine designs prior to World War Two. As such, it incorporated some of the latest thinking. Nine main bearings provided a crankshaft main bearing support between each 135 degree opposing pair of cylinders. The square bore and stroke lowered piston speed and promoted crankshaft rigidity, no small matter for an engine with eight cylinders in line per cylinder bank. The side valve engine design was no handicap for the time because the era's typical top engine speed of 3400-3700 RPM provided little opportunity to exploit the high speed breathing efficiency of overhead valves. Luxury car drivers presumably valued smoothness and silence more than high speed power. Hydraulic valve lifters promoted silent running and an absence of periodic adjustment. Unlike most cars of the era, an external oil filter safeguarded the precision valve lifters. Despite the use of side valves, the engine produced as much power as the prior 45 degree V16, and with much less complexity. The earliest engines produced featured an innovative friction wheel drive to the generator. This was soon replaced by a conventional V belt drive.

The definitive engineering report on the 135 degree Cadillac V16 engine is "The Evolution of the Cadillac Sixteen engine," by E.W. Seaholm, in charge of Cadillac engine design. It was published by the industry journal "Automotive Industries," November 27, 1937.

[edit] V12

Cadillac also built a V12 engine based on the Series 452 engine for 1930 through 1937. It retained the 45° vee-angle and displaced 368 in³ (6 L) from a 3.125 in (79.4 mm) bore and 4 in (101.6 mm) stroke. Output was rated at 135 hp (101 kW) with two carburetors. The cars were designed to make a statement, so all engine wiring and plumbing was hidden from view.

The V12 was used in the Fleetwood-bodied V-12 models: