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 2003, but these have yet to be put into production. Series 452 With its chief competitor, Packard, already having sold a V12 engine against Cadillac's eight-cylinder cars, work began late in the 1920s under Hemmings 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. The original Cadillac V16 could be said to be two overhead valve Buick Straight-8 engine engines on a common crankshaft and crankcase, because each bank operated entirely independently of the other with no other shared components. It sported a narrow 45° bank angle for use in the new Cadillac chassis Cadillac Series 90 V-16 (which became the Fleetwood). The engine was well engineered, with a counterweighted crankshaft (quite a mathematical challenge at the time), overhead valves, and hydraulic tappets. It also had only two single barrel updraft Stromberg carburetors, one for each bank. The 452 V16 had a bore and a stroke, giving an engine displacement of . It was therefore known as the Series 452. Cadillac initially rated the engine at . It was capable of powering the heavier models to speeds in excess of , and for some of the lighter examples. In all, 3878 Series 452s were built. This engine was used in the various V-16 models: 1930–1934 Series 452 ("A" through "C") 1935 Series 60 1936–1937 Series 90 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 , giving an overall displacement of and were sidevalve instead of the previous overhead valve design. Cadillac rated these engines at the same 185 bhp (138 kW) as the previous series. These engines were known