By 1955 Packard was nearly out of business, but the grand old Detroit automaker went down swinging with an all-new V8 engine. Here’s a closer look.

Packard’s sterling reputation in the auto industry was in large part built on its engines. The company’s Twin Six V12 and straight-eight designs set the standards for the luxury car field, and its big marine and aviation powerplants broke important technological ground and eventually helped the Allies win World War II.

But after the war, unfortunately, Packard was painfully slow in bringing an overhead-valve V8 to market—its V8 did not appear until 1955, six years after Cadilllac and Oldsmobile. This leisurely reaction to an important market trend couldn’t have done much to slow the automaker’s painful slide through the sales charts or its eventual demise. At best the effort could be called too little, too late. Still, the Packard V8 is an interesting and impressive engine and well worth a closer look.

While totally conventional in design, the V8 was over-engineered and overbuilt in typical Packard fashion, with massive 5.00-inch bore centers that could support potential  displacements of 500 cubic inches or more. As it was, three sizes were offered: 320, 352, and 374 CID. All three shared the same 3.500-inch stroke, while the various displacements were achieved with progressively larger bores: 3.815 inches, 4.000 inches, and 4.125 inches, respectively.

The 320 CID version was standard in Packard’s junior Clipper line for 1955, and was also supplied to American Motors for use by Nash and Hudson—as part of a partnership between Studebaker-Packard and AMC that quickly came unraveled. The 352 was used in the senior ’55 Packards, ’56 Clippers, and ’56 Nash Ambassador, while the 374 was the standard engine in the big Packards for ’56, the final year for the “real” Detroit-built Packard. In a touch of irony, the Packard V8 was never used in the South Bend-built Packard Hawks of 1957-1958, which boasted a Studebaker engine.

Construction details included a beefy cast crankshaft with six counterweights, fully machined combustion chambers with generous squish/quench area, and symmetrical cylinder heads with siamesed exhaust ports. Since the old East Grand Boulevard plant was declared hopelessly obsolete for the purpose, the V8 was produced in a brand new plant adjacent to the Packard Proving Grounds north of Detroit, where Packard’s advanced Ultramatic automatic transmission was also manufactured.

The absolute top of the heap in the Packard V8 family is the dual-quad 374 CID job offered in the 1956 Caribbean, above. With a compression ratio of 10:1 and a pair of Rochester 4GC four-barrel carburetors, this version was rated at 310 horsepower, which made it one of the most powerful V8s offered by Detroit in ’56.

Ansen’s Speed Shop, a prominent Southern California speed equipment supplier, saw potential in the Packard V8 and built a dragster to showcase a full line of performance goodies the company had developed for the engine, including a GMC 6-71 supercharger setup (below). But since production of the Detroit-built Packards ended in June of 1956, and the in-house V8 with it, the demand ever materialized. Packard V8s in hot rodding and racing were a rare sight, and they remain so today.