Plymouth Valiant - 1960–1962

In May 1957, Chrysler president Lester Lum "Tex" Colbert established a committee to develop a competitor for the increasingly popular small imports. Virgil Exner, Chrysler's chief stylist, designed a car that was smaller and lighter than a full-size car without sacrificing passenger and luggage space. Originally named the Falcon after Exner's 1955 Chrysler Falcon concept car, the vehicle was renamed the 'Valiant' honoring Henry Ford II's request to use the name for the Ford Falcon. The Valiant debuted at the 44th International Motor Show in London on October 26, 1959. It was introduced as a 1960 model and was officially considered a distinct brand, advertised with the tagline 'Nobody's kid brother, this one stands on its own four tires.' From the 1961 model year, the Valiant was classified as a Plymouth model. The 1961-62 Dodge Lancer was essentially a rebadged Valiant with different trim and styling details.

The Valiant was less radical in configuration than General Motors' compact Chevrolet Corvair, which had an air-cooled rear-mounted engine, but was considered more aesthetically daring than the also-new Falcon which had a more conventional look, while the Valiant boasted a radical design that continued Exner's Forward Look styling with "sleek, crisp lines which flow forward in a dart or wedge shape." The flush-sided appearance was a carried-over feature from Chrysler's Ghia-built D'Elegance and Adventurer concept cars which also gave the Valiant additional inches of interior room. With its semi-fastback and lengthy hood line, many automotive publications of the time thought the Valiant's styling was European inspired. While the Valiant was all new, specific design elements tied it to other contemporary Chrysler products. Features such as the canted tailfins tipped with cat's-eye shaped tail lamps and the simulated spare tire pressing on the deck lid were thematically similar to those on the Imperial and the 300F. According to Exner, the stamped wheel design was used not only to establish identity with other Chryslers, but to "dress up the rear deck area without detracting from the look of directed forward motion."

The Valiant featured an all-new 6-cylinder engine, the famous Slant-6, which had its inline cylinders canted 30° to one side. This allowed a lower hoodline, a shorter engine — the water pump was shifted laterally — and efficient, long-branch individual-runner intake and exhaust manifolds that benefited from Chrysler's pioneering work in tuned intakes. The cast-iron block Slant-6 gained a reputation for dependability as it was initially engineered as an aluminum block engine with a robust casing. Over 50,000 die-cast aluminum versions of the 225 cu in (3.7 L) engine were produced between late 1961 and early 1963.

The 1960 Valiant exemplified Chrysler's leadership in aluminum die casting. While the aluminum Slant-6 engine block wouldn't enter production until 1961, the Kokomo, Indiana foundry produced a number of aluminum parts for the 1960 Valiant, and was instrumental in reducing the total weight of the car. The 1960 model contained as much as 60 lb (27 kg) of aluminum in structural and decorative forms, with the majority of the material used in cast form as chassis parts. These parts included the oil pump, water pump, alternator housing, Hyper-Pak (see below) and standard production intake manifolds, Torqueflite A-904 automatic transmission and torque converter housing and extension, and numerous other small parts. These cast-aluminum parts were roughly 60% lighter than corresponding parts of cast iron. A cast aluminum part had the benefit of reduced section thickness where strength was not a vital consideration. Section thickness of cast-iron parts were often dictated by casting practice, which required at least 0.1875 in (4.76 mm) to ensure good castings. Exterior decorative parts stamped from aluminum were lighter than similar chromium plated zinc castings. The entire grille and surrounding molding on the Valiant weighed only 3 lb (1.4 kg). If this same assembly had been made of die-cast zinc, as many grilles of the era were, it would have weighed an estimated 13 lb (5.9 kg). An estimated 102 lb (46 kg) — about 4% of a Valiant's total shipping weight — was saved with the 60 lb (27 kg) of aluminum parts.

The Valiant A-body platform utilized "unit-body" or "unibody" construction (not used by the Chrysler Corporation since the Airflow models of the 1930s) rather than "body-on-frame" construction. Instead of a bolted-in forestructure used in other unibody designs, the Valiant incorporated a welded-in front understructure and stressed front sheet metal. The fenders, quarter panels, floor and roof contributed to the stiffness of the body shell. A unit wheelbase comparison showed the Valiant to be 95% stiffer in torsion and 50% stiffer in beam than a 1959 Plymouth with separate body-on-frame construction. Dynamic testing showed that high structural resonant frequencies were attained, indicating greater damping and reduced body shake.

The front suspension consisted of unequal length control arms with torsion bars, while the rear suspension used a live axle supported by asymmetric leaf springs. Chrysler used this design through the entire production of the Valiant and other A-body models, with revisions to the suspension components themselves for the 1962, 1967, 1968, and 1973 models.