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Packard’s bold bid for power includes a radical new chassis and the industry’s biggest engine.
The veil of secrecy that shrouded the new 1955 Packard V8 has been surpassed only by the Iron Curtain. Usually, new automotive developments are released to members of engineering groups and the press some time before the cars fill the showrooms, but this year Packard withheld specific information of two very significant innovations. Meanwhile, a few expert rumormongers had a field day. According to them, the new Packard V8 engine was a 400-cubic inch, two-cammed affair with an aluminum block. The actual result is slightly less spectacular, but nonetheless quite worthy of a detailed discussion.
In 1946, Packard instituted an engine development program to explore the possibilities of new and novel designs suitable for future production as successors to the venerable straight eight. To be sure, many unusual designs were tested and evaluated, as were new methods and materials (including aluminum cylinder blocks). By 1949, most of the details of the new Packard engine were established; that is, nearly everything except the piston displacement which was originally set at 269 cubic inches. The leaps and bounds by which other manufacturers increased piston displacement, power and torque prompted Packard engineers to reconsider and redesign, so they wouldn’t be caught flat-footed with an engine that would be under powered to sell the increasing numbers of performance-conscious buyers. So they went to the other extreme and made the production engines big, with provisions for going bigger whenever the need arises.
The new Packard V8 is a 352-cubic inch engine having a four-inch bore and a 3 1/2-inch stroke, which results in the favorable stroke/bore ratio of .88 to 1. The maximum advertised brake horsepower is 260 obtained at an engine speed of 4600 rpm and maximum advertised torque is 355 pounds-feet between 2400 and 2800 rpm. The same size engine in the Clipper “Custom” produces 245 brake horsepower at 4600 rpm and 355 pounds-feet of torque at 2600 rpm. The smaller 320-cubic inch engine (3 13/16-inch bore, 3 1/2-inch stroke) in the Clipper “DeLuxe” and “Super” series yields 245 brake horsepower at 4600 rpm and 325 pounds-feet of torque at 2600 rpm.
The Packard Division of the newly formed Studebaker-Packard Corporation did supply a 320-cubic inch V8 engine for both the Hudson “Hornets” and the Nash “Ambassadors” for the 1955 model year. Basically, these, are “detuned” versions of the 320-cubic inch Clipper engine that put out 208 brake horsepower at 4200 rpm and 300 pounds-feet of torque at 2300 rpm.
Revisions 1956:
352 CID V-8: Fitted to Clipper DeLuxe, Super and AMC Nash and Hudson. Overhead valve. Cast iron block. Displacement: 352 cid. Bore and stroke: 4.00″ x 3.5″. Compression ratio: 9.5:1. Horsepower: 240 at 4600 RPM (220 HP in Nash & Hudson). Torque: 350 ft. lbs. @ 2800 (320 in Nash & Hudson). Carburetor: Carter Type WGD two-barrel Model 2393S.
352 CID V-8: Fitted to Clipper Custom, Executive and Studebaker Golden Hawk. Overhead valve. Cast iron block. Displacement: 352 cid. Bore and stroke: 4.00″ x 3.5″. Compression ratio: 9.5:1. Horsepower: 275 at 4600 RPM. Torque: 380 ft. lbs. @ 2800. Carburetor: Rochester Type 4GC four-barrel carburetor Model 6480253.
374 CID V-8: Fitted to Packard Four Hundred and Patrician. Overhead valves. Cast iron block. Displacement: 374 cubic inches. Bore and stroke: 4.125″ x 3.5″. Compression ratio: 10.0:0. Horsepower: 290 @ 4600 R.P.M. Torque: 405 ft. lbs. @ 2800. Carburetor: Rochester Type 4GC four-barrel Model 6480253.
374 CID V-8: Fitted to Packard Caribbean. Overhead valves. Cast iron block. Displacement: 374 cubic inches. Bore and stroke: 4.125″ x 3.5″. Compression ratio: 10.0:0. Horsepower: 310 @ 4600 R.P.M. Torque: 405 ft. lbs. @ 2800. Carburetor: Two Rochester Type 4GC four-barrel carburetors fitted as follows: (front) Model 6489090; (rear) Model 6489091.