The Chevrolet Corvette C3, the historical car from chevrolet

History corvette c1

The new generation was characterized by a thoroughly new design for both the interior and the body. The eye-catching body design went down in automotive history as the « Coke Bottle Corvette ». Wheelbase and large parts of the chassis were taken from the C2. The fold-out main headlights were pneumatically operated rather than electrically from 1968. The coupés were equipped with two removable roof halves (T-top) and a removable rear window.

Chevrolet Corvette C3

Concepts corvette c1

The design of David Holls’ C3 borrowed heavily from the 1965 Mako-Shark-II show car concept car, which in turn cited numerous elements of the 1954 Arnolt-Bristol designed by Bertone. The « Mako Shark II » (project designation XP-830) was first presented to the public in April 1965 at the « New York International Auto Show » as a design study. The development costs of this non-drivable prototype were almost three million US dollars. The « Mako Shark II » made its second debut at the « Paris Motor Show » on October 5, 1965, but this time it was equipped with an eight-cylinder, 7.0-liter engine (427 in3) and was ready to drive. This car was ultimately the basis for the new « Stingray ».

With numerous futuristic details such as a rectangular steering wheel, a retractable rear spoiler or a bumper that could be extended for improved protection, the two « Mako-Shark II » concept cars caused a sensation in 1965, but these ideas were not adopted in series production. In contrast, Corvette designer David Holls adopted the strongly curved body line of the show cars for the third generation.

Production corvette c1

Production began in September 1967.

In 1981, a move was pending for the second time since December 1953: Production was moved from St. Louis/Missouri to Bowling Green/Kentucky, i.e. to the plant where the Corvette still comes off the production line today. Unusual was the parallel production of the C3 models in June and July 1981. In St. Louis the uni-colored versions were produced in these two months, while in Bowling Green the two-colored versions were produced.

Production ran until October 1982, and a total of 542,861 Corvette C3s were built, including 70,586 convertibles built only from 1967 to 1975. With nearly 543,000 models built in 15 years, the C3 continued the success of its predecessors. The best production year in the history of the Corvette ever, 1979 with exactly 53,807 units (after 46,776 units in 1978), also falls into the era of the C3 Corvette. This model held up relatively steadily until 1981 (40,606 units), but in the final model year of 1982, production dropped to 25,407 units. Prices started at $4663 for the coupe and $4347 for the convertible in 1968. By 1975, the price had risen to 7117 USD for the coupe and 6857 USD for the convertible. The C3 now stood no chance against European and Japanese competition as of 1982. This was to change from 1983 with the successor model Corvette C4.

Chassis

The two-stage automatic transmission « Powerglide » from the C2 had become obsolete and was replaced by the new automatic transmission « Turbo Hydra-Matic » with three stages. In 1967, over 80% were delivered with a manual transmission.

General Motors engineers again demonstrated their innovative spirit in the chassis area, but not until the penultimate model year of the Corvette C3. From 1981, the transverse leaf springs of the rear axle were made of fiberglass-reinforced plastic. The advantages lay in the weight of only around four kilograms, the prevention of rust formation and a fivefold increase in durability.

Engine chevrolet corvette c3

From 1968, the 5.4-liter (327 in3) « small-block » eight-cylinder engine familiar from the C1 and C2, now with 300 gross SAE HP (also known as bhp for short) output, was used as the standard engine; from 1969, the 5.7-liter (350 in3) was standard with unchanged output. The 7.0-liter « big-block » engine (427 in3) was also available again, with outputs ranging from 390 SAE-HP to 435 SAE-HP.

The hunt for the largest displacement and highest power reached its absolute peak in 1971. The « big block » of a Corvette was never larger than between 1970 and 1974: 7.4 liters of displacement resulted in a capacity of over 930 cc per cylinder. In 1971, 435 SAE HP marked the highest output of a production version in the history of the American sports car legend up to that time, and that despite the fact that compression was scaled back in this model year.

Beginning in 1972, oil prices and dramatically increased insurance premiums for high-performance vehicles were reflected in a reduction of the maximum output to 270 bhp; a base Corvette even had only 200 bhp. By the end of its build, the C3 could still mobilize a maximum of 230 bhp.

Worth mentioning is the « ZL1 » engine, which was officially ordered by only two customers in 1970. A red Corvette coupe was built by engineer Gib Hufstader for drag racing. The car completed the quarter mile in 10.6 seconds with a top speed of 132 mph (212 km/h). The second car was a white convertible designed by chief engineer Zora Duntov for road racing. This car reached a top speed of 200 mph (321 km/h). According to the brochure, the engine produced 430 bhp, five less than the « most powerful » engine. Basically, however, the ZL1 was an « L88 » engine with an aluminum block, modified engine parts, and about 585 SAE horsepower. Smoothed exhaust ports were incorporated and different valves were used. The engine had a compression ratio of 11.45 : 1. The engine allowed the use of Holley 4500 NASCAR carburetors with a mixture flow of 1200-1400 cfm (cubic feet per minute). This equates to approximately 2040-2380 m3/h. Driver John Greenwood achieved numerous race wins including the SCCA championship title.

This standard engine could also be ordered in the previous model C2 from 1967.

General Motors wanted to prevent this monster from getting into the hands of people who just basically choose the most powerful engine in the brochure with the lower power rating. Regardless of whether it was the ZL1 or the « normal » L88, GM basically didn’t misstate the power, they just stated a value that was realized at a lower RPM. Also, nowhere in the sales brochures did it say that the L88 could reach much higher RPMs to make its extra power. In one brochure, Chevrolet also warned against using the Corvette with ZL1 option as a street car.

The ZL1 was considered the fastest and most powerful production Corvette ever for 39 years until the release of the C6 ZR1. However, the power output of U.S. vehicles was quoted as gross SAE horsepower in America until 1972. These SAE horsepower figures are considerably higher than the DIN horsepower figures due to different measurement methods. Therefore, such performance data for U.S. vehicles before 1972 should be treated with appropriate caution, since the measurement did not include add-on units such as generator, water pump and fan.

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