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The
1957 Corvette
Ramjet Fuel Injected |
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The
1957 Corvette
Ramjet Fuel Injected |
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Chevrolet got their sports car right for 1957, as the Corvette finally gained power to go along with its outstanding styling and road feel. Many Corvette enthusiasts consider the 1957 Corvette the most aesthetically pleasing body style of the first generation Vettes. Backing up the beautiful styling was the Corvette's most powerful engine to date, the 283 cid V8. First carbureted non Corvette edition below.
A bored out version of the 1956 265 cid V8, the 283 came in five versions. The base form had a four barrel carburetor and was rated at 220 bhp. Next came an early fuel injected version rated at 250 bhp for the automatic transmission, and then the dual four barrel 283 below rated at either 245 or 270 bhp. Last was the 283 hp fuel injected engine.
In May of 1957, the true performance version of the 283 made its debut. Sporting an advanced fuel injection system, the new "fuelie" 283 made 283 bhp. Its 1 horsepower per cubic inch output was played up in advertising and by the media, who conveniently forgot about the 300B. At the same time, Chevrolet introduced its new four speed manual transmission and the Corvette was on its way to stardom. Available as of April 9, 1957, 664 1957 Corvettes were so equipped at an extra cost of $188.30. When equipped with the 283 fuel injected engine, 4.11:1 rear axle, and the Borg Warner T10 transmission, the Corvette could accelerate from 0-60 in less than six seconds and do the quarter mile in the low 14 second range at over 100 mph.
For those who wanted even more performance, Chevrolet offered two option packages. Checking RPO 579E got the buyer the fuel injected 283 cid V8 with cold air induction and a big tachometer on the steering wheel. There was also a special "racing only" package coded RPO 684, which consisted of heavy duty springs, shocks, and sway bar, positraction rear axle, quicker ratio steering, and metallic brakes. Also available in 1957: RPO 684, a racing suspension intended for serious racers. The cost was $780.10 and was installed on only 51 Corvettes in 1957. From mid 1957 through 1962, 935 Corvettes were shipped with the factory heavy duty package. Research and testing supervised at Sebring in 1956 by John Fitch resulted in many brake and suspension modifications which were used on 'factory' racers in 1956, then offered as an RPO in 1957. The RPO brake shoe linings were Cerametalix, (now marketed as Cerametallic clutch material) which only worked well when hot; conventional shoes had to be substituted for street use. Cerametalix linings were used on aircraft brakes and are copper in color. The RPO 684 front shoes are 2 1/2" wide and the rears are 2". Early Cerametalix linings came in pairs with two pads on the primary shoe and four pads on the secondary shoe; in 1959 this was changed to three and five pads respectively. Cerametalix linings were also available OTC to fit regular, base drums. These linings were so tough that you used up and replaced drums, not brake shoes. Besides the vastly improved brakes, a heavier front sway bar, heavy duty shocks, firmer springs, fast steering adaptor, and longer rebound straps were included. Initially in 1957 there was to be a heavy duty suspension package separate from the brake package; however, it appears that this tentative RPO 581 was never offered. RPO 684 became available in early April 1957, and 51 cars were sold with this option during the remainder of the model year. RPO 276, for wider wheels, was a necessary option because of the shape of the early finned brake drums. Probably not coincidentally, in the 1957 model year 51 cars were shipped with wide wheels. This implies that no '57s should have wide wheels and not have RPO 684. Most likely these 51 cars included the 43 that were equipped with RPO 579E, the special fuel injection airbox assembly. The RPO rear springs had five leaves without anti squeak liners compared to the four leaves on base springs, which had impregnated cardboard liners. The four long leaves of the RPO springs have lengthwise grooves like the base spring but their short fifth leaf was flat. These rear heavy duty springs generally have six heavy riveted retaining straps. A few springs have been reported with thin bands like the base springs. The 1957-58 RPO cars included a complex system of ducts to lead cold air from the front of the car to the rear brake scoops. The 1958 rear ducting was more refined than that of 1957 in that it included 'elephant tusk' fiberglass ducts up high inside the front fender wells. These ducts were attached to the metal reinforcing straps that early '58s had in their front fenders. The base car fender reinforcements were dropped half way through the model year, yet, necessarily, '58 RPO cars retained them until the end of the model year. All RPO 684 cars, except early '57s, had extra parts to accommodate their heavy duty shocks. The RPO shocks were thicker, and to clear the front springs the lower clamshell retainer for the front shocks had an offset hole. The base retainer has its shock rod hole in its center. The clamshell retainers seem to often be broken and many RPO 684 cars are found with the base retainers, which were serviced by GM until recently. The rear shocks required a larger, heavier top support on the frame cross member. At the factory when the suspensions were being assembled onto the inverted frames, the base retainers were knocked off and the heavier RPO V shaped pieces were welded on. This welding consists of crude tacks rather than neat seams. On all 1957-62 RPO 684 and 687 cars, eccentric pivot pins were used at the top of the brake backing plates to allow up and down centering of the shoes, reminiscent of the Chrysler design. The back of the pin itself has a hex profile. The large locking nut is loosened and the pin is turned with a wrench to the point of minimum drag. All brakes are self centering front to rear, and base and RPO 686 pivot pins are not eccentric. The front base pivot has a squared shaft to lock into the base front backing plate; base rear pivots are round and can be substituted for the eccentric RPO pivots if necessary.
The innovation solved a fuel starvation problem caused by float
bowl sloshing under high cornering with carbureted engines under race conditions. The fuel injection
system also enabled Chevrolet to boast 1 hp per cubic inch of displacement with the 283 cu. in., 283 hp engine. To keep this development in perspective, consider this; almost all of the high priced supposedly advanced competition, including Jaguar, Porsche, Ferrari and Lamborghini, did not go with fuel injection until the 1970s or later. The new system was complex and costly, however. At $484.20, this one option represented 15% of the price of a base Corvette. 1,040 buyers checked the box on the order form, or 17%. The complexity also resulted in a high maintenance reputation. Not up for debate is the way the market treats fuel injected Corvettes of the era. Corvette enthusiasts went for it in a big way in 1957 and more so 50 years later as a collectable; the price premium for a "Fuelie" as they are often called is significantly higher than their carbureted cousins. Again, production numbers rule. 1957 and subsequent Corvettes proudly wore their new technological identities on the front fenders and trunk lids.
1957 Corvette Facts
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