By 1936, the original 1915 Cadillac V8 design was overdue for an overhaul. Its replacement was new and improved in every way.

In 1915, Cadillac pioneered the V8 in volume production in America and in the world.  (See our feature here.) And while there were continual updates through the years, including detachable heads in 1918 and the game-changing crossplane crankshaft in 1924, by the 1930s the original V8 was due for a replacement. Cadillac’s V8 for 1936 shared the 90 degree bank angle and L-head valve layout of the original, but from every other angle it was totally new.

The 1915 V8 used the method of construction that was prevalent in its time: cast-iron cylinders bolted to a cast-aluminum crankcase. It made good sense then, but by the ’30s this had become an expensive and complicated way to build an engine. The 1936 V8 was the first monobloc Cadillac, with the crankcase and eight cylinders cast in one contiguous chunk of gray iron—stiffer, stronger, less costly to manufacture.

The new engine also dispensed with the fork-and-blade connecting rods of the original, adopting more conventional side-by-side rods paired on common crankshaft journals. To accommodate the revised layout, the right cylinder bank was offset to the front by the width of one connecting rod. The crankshaft continued to rely on three main bearings and six counterweights, but the main and rod journals were enlarged and the lubrication system was modernized.

Since the ’36 Cadillac and the Ford V8 introduced in 1932 are both monobloc, L-head V8s, comparisons are naturally drawn, but beyond their basic layouts these were  remarkably different engines. The Ford V8 was designed for low cost and speed of manufacture, while at Cadillac the priorities were silence, smoothness, and power. As a result, the Cadillac was much larger and heavier, with a deeply skirted block casting and a sturdy upper structure to support top-exiting exhaust ports. Fully assembled, the Cadillac V8 weighed nearly 900 lbs, compared to less than 550 lbs for the Ford. There’s one good reason that unlike the Ford V8, the Cadillac was seldom seen in competition.

The Cadillac V8 also included a number of premium features for the luxury car audience. They included hydraulic valve followers, an advance first seen on the 1930 Cadillac V16, reducing engine noise and eliminating the need for periodic adjustment. Also, the flywheel incorporated a flexible disc between the hub and rotating mass to reduce torsional vibration. Naturally, these costly extras were enabled by Cadillac’s starting list price of $1,645 in 1936—more than three times as much as a new Ford V8.

For the 1936 introduction, the new V8 was offered in two displacements. The Series 60 engines featured a 3.375-in bore and 4.500-in stroke for 322 cubic inches and was rated at 125 hp at 3,500 rpm. The upmarket Series 75 used the same stroke and a bore of 3.500 inches for 346 cubic inches and a rating of 135 hp at 3.400 rpm, the two  engines sharing a 6.25:1 compression ratio. After 1940 the 322 CID version was dropped, and the second-generation V16 as well, so from 1941 through 1948 all Cadillacs were powered by the same trusty 346 CID L-head V8.

So while the 346 Cadillac V8, as it became known, never gained the notoriety of some other Cadillac engines, it actually proved to be one of the GM division’s most successful and dependable powerplants. The engine even saw combat duty in World War II, with twin Cadillac V8s powering the M5 Stuart and M24 Chaffee tanks used in infantry support. It wasn’t replaced in production cars until 1949 with the introduction of the high-compression, short stroke, overhead-valve Cadillac V8.

1936 Cadillac 60 Series Coupe