V16 engine

A V16 engine is a V engine with 16 cylinders. Engines of this number of cylinders are uncommon in automotive use.

A V16 engine is perfectly balanced regardless of the V angle without requiring contra-rotating balancing shafts which are necessary to balance engines with odd numbers of cylinders in-line or those equipped with counterweighted crankshafts like the 90° V8. In addition V angles of 45° and 135° give an impulse every 45°, so are optimal solutions, for even-firing and non-split bearing crankshaft journals.

V16 engines are rarely used in automobiles because V8s or V12s of the same displacement typically produce just as much power, and are much less expensive to manufacture and maintain. The few V16s that have been produced were used in high-end luxury and high-performance automobiles due to their smoothness (low vibration).

Today, the most common applications for V16 engines are railroad locomotives, marine craft, and stationary power generators.

Howard Marmon had begun working on the world's first automotive V16 engine in 1927, but was unable to complete the production 'Sixteen' model until 1931. By that time, Cadillac had already introduced their V16, designed by ex-Marmon engineer Owen Nacker. Peerless, too, was developing a V16 with help from another ex-Marmon engineer, James Bohannon.

The Cadillac Series 452 was the most exclusive model of the marque from January 1930 until 1940, with this type of engine. Two varieties were built. From 1930 to 1937, Cadillac used a 452 CID (7.4 L), OHV motor with a 45° V. For 1938, a new 431 CID (7.1 L) design was introduced for the Series 90, with a flathead valvetrain and an angle of 135°; this resulted in a much lower cowl height. The 431 was in many ways a superior engine, producing as much power as its immediate predecessor while being far less complex, had a stiffer crankshaft which aided durability and smoothness, and even had an external oil filter, a rarity for any car at any price in those days. However, it was never as popular or highly regarded as its 452 CID predecessor.

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