Engines of Yore:  Part 6.
             Cadillac V16 and V12.    created 07 January 1993
             by Dave Williams   [email protected]

The engines have a 45 degree cylinder bank angle, two eight or six cylinder heads, and a built-up crankcase. The crankcase is a deep, wide casting with the oil pan rail well below the crank centerline (which Ford used to call a "Y" block, which is the generally used term for it now). The cylinder blocks are separate and bolt in from the top, like normal motorcycle practice. The water jacket is only a few inches long and sits outside the crankcase; the rest of the cylinder block slides inside the crankcase. The blocks are held down with studs and acorn nuts. The cylinder heads are held to the blocks with short bolts. The oil pan and valve covers were cast aluminum.

The crankshaft has eight throws and five steel-backed, replaceable main bearings. Connecting rods sit side by side as per modern practice. The rods are very long, have conventional caps and through bolts, and are rifle-drilled for oiling the pins, which are full floating within the pistons. The crank is drilled for full-pressure oiling.

The 16 cylinder crankshaft had 90 degree throws. Presumably the 12 cylinder crank had 120 degree throws, or the engine would not have been in proper balance.

The camshaft is located in the center of the vee, with cylindrical roller followers. The shaft mounted rocker arms are unusual. The rocker is bored larger than the shaft and mounts on an eccentric bushing. This bushing has a short arm which is operated by spring and a small piston actuated by engine oil pressure. The arrangement is called a "valve silencer" and takes up slack in the valvetrain much like a modern hydraulic follower, or (a closer cousin) the odd ramp-and-pin layout Ford used in some 1950s-era sixes. Though a conventional adjustor screw is provided on the pushrod side of the rocker, the text claims the silencer automatically provided for any adjustment required due to wear or valve face refinishing. Dual valve springs were used.

As was apparently the practice in high end engines of the era, the generator and water pump were positively driven, in this case by the triplex chain which drove the camshaft. The chain was also fitted with an idler and automatic tensioner. The distributor was located in the center of the vee and had either 16 or 12 wires from a single cap. The spark plugs were located on the inside of the vee.

Each cylinder bank had its own carburetor and exhaust manifold, located on the outside of the vee. This arrangement kept the engine lower than a central carb layout and allowed use of conventional (for the time) updraft carburetors for smoothness. Each carb had a steel inlet tube and a large "muffler", or intake silencer to minimize induction drone.

The engine was fitted with a 16-disc dry multiplate clutch, very similar in design to some motorcycle clutches, and a three speed manual transmission. Multiple disc clutches allow more torque capability for the same pedal pressure, though in the case of the Cadillac it probably used very little pedal pressure and moderate torque capability.

note:  The Marmon V16 of 1931 was very similar, only the single 2V
       carburetor sat in the vee on a normal-style intake manifold,
       spark plugs were on the outside of the vee, and the block
       and heads were aluminum instead of iron.  It displaced 491
       cubic inches and was rated at 200 brake horsepower at 3400 RPM,
       and weighed 930 pounds including accessories and three speed
       manual transmission.  The connecting rods were the fork-and-
       blade type instead of side-by-side.  Oddly, the specification
       state the Marmon used metric thread spark plugs.

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can you help me...help me get out of this place?...slow sedation...
ain't my style, ain't my pace...giving me a number...NINE, SEVEN, EIGHT
(Nazareth)               XJ900 TURBO at 15psi          DoD# 978  KotFAQ
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