When it was introduced in 1930, Cadillac’s mighty V16 engine represented the pinnacle of automotive engineering.
When the Cadillac V16 made its debut at the New York Auto Show on January 4, 1930, the automotive world was gobsmacked. In those days General Motors was arguably the greatest engineering company in the world, with technical resources second to none and a staff that boasted some of the greatest minds in the business, including Charles “Boss” Kettering, Owen Nacker, and Earl A. Thompson. With the Cadillac V16, GM raised the bar in engineering excellence, to a level many automobile manufacturers couldn’t reach.
The Cadillac V16 was such a grand, over-the-top engineering statement, in fact, that it’s easy to lose sight of how fiendishly clever it was in its smallest details. Rated at 175 horsepower at introduction, the V16 was more powerful than most every other American car on the market (the Duesenberg was rated at 265 hp, notably). But the engine wasn’t designed for all-out performance; rather, Owen Nacker and his team carefully optimized smoothness and flexibility.
With a bore of three inches and a stroke of four inches, the 16 cylinders displaced a mammoth 452 cubic inches. But the torque curve was deliberately engineered to mimic the characteristics of the standard Cadillac V8, so the V16 could share the existing V8 drivetrain. Intake and exhaust systems were located on the outboard side of each cast-iron cylinder bank, so the V16 was in effect two overhead-valve straight eights on a common crankcase, if you will. (The two cylinder blocks were cast iron and the crankcase was aluminum.) With the banks separated 45 degrees, the engine and its 135-lb crankshaft were perfectly balanced, and with eight firing impulses per crankshaft rotation (16 per four-stroke cycle) it was dead smooth. There was virtually no perceptible vibration at idle, and the engine could pull top gear from 2.5 mph to over 100 mph, depending on gearing and bodywork. .
While the V16 was an engineering tour de force, commercially it was only a qualified success. Cadillac offered the mighty V16 on a 148-inch wheelbase chassis in 54 lavish styles, and sales were brisk at first, as more than 2,500 were produced in the first year. But sales quickly plummeted as the limited demand was exhausted and the nation’s economic depression deepened, and in the final two years, 1936 and 1937, the annual output dwindled to barely 49 units. Cadillac also introduced a 368 CID V12 closely based on the V16’s architecture, giving the brand a head-on competitor with the V12 Packard and Lincoln, but it didn’t fare much better.
For 1938, Cadillac rolled out a totally redesigned V16 (above). With its nearly pancake-like 135-degree bank angle and L-head valvetrain, it wasn’t nearly as attractive as the previous 45-degree V16 and its beautifully enameled rocker covers. (Harley Earl’s styling team reportedly assisted in the original V16’s visual presentation.) But in its own way this new V16 was as clever as the original. With its square 3.25-in bore/stroke dimensions and aggressive 6.67:1 compression ratio, it sacrificed nothing to the original in performance. Additionally, it was six inches shorter and 250 lbs lighter than the first-generation V16, and with its flattened proportions, it could fit in the same chassis/body package as the standard V8. This second-generation V16 remained in production through 1940, but the annual production numbers remained small.
Naturally, nobody is more aware of the magic and mystique of the mighty V16 than the Cadillac Motor Division itself. The GM brand has periodically revisited the concept over the years, most recently with the XV16 concept engine of 2003 (below). This engine was actually based on the Chevrolet/GM LS architecture and a handful were built, including the one that powers the Cadillac Sixteen, a fully roadworthy test vehicle and show car. Will there ever be another Cadillac V16 production car? As the electric future looms, that seems highly unlikely. But we will always have the original.
Excellent article with fresh insights. Nice work.
Is it me or is the original OHV and the later one a flathead?.
Hardly a move forward.