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Оглавление1956–1962 C1b: V-8s and Fuelies Take Over
126 Were any 1956 Corvettes built with 6-cylinder engines? Although seven Blue Flame machines emerged from the St. Louis plant in 1955, by 1956 the 6-cylinder was strictly a thing of Corvette’s past.
127 Did Ford’s Thunderbird save Corvette from extinction? Yes, absolutely. Chevrolet was about to discontinue the Corvette at the end of the 1955 model run, but after witnessing Ford’s sale of 16,155 Thunderbirds in 1955, General Motors decided to keep fighting and gave Corvette a reprieve. It wasn’t so much a case of profiteering, but rather a matter of corporate pride.
128 Although certain elements of the chassis and suspension were carried over from 1955, the 1956 Corvette received an all-new body and interior. Naturally, the launch was a big event, so what better place to hold it than the Waldorf Astoria Hotel Grand Ball-room, the same place the first Corvette debuted in 1953?
129 It was common practice for GM Motorama show-car stylists to share certain styling features among their dream-car renderings. Although the 1956 Corvette marked the first (and only) appearance of crescent-shaped side coves on a mass-produced GM offering, numerous Motorama show cars also carried the theme. Among them were the 1953 LeSabre, 1954 LaSalle II, the 1954 Olds F-88, and 1955 Chevrolet Biscayne. The Biscayne’s use of the coves was most unusual; they were reversed to give the impression of giant missiles set into the flanks of the body.
A Corvette institution, the side coves were considered for use on other GM makes and models. This 1958 model marked the first year for the added shielding adjacent to the wheel opening.
130 Corvette’s side-cove theme was taken to the extreme on certain other Motorama dream cars. On the Oldsmobile 88 Delta and Cutlass and the Buick Wildcat II, all from 1955, the coves were deeply set under the body, exposing the trailing ends of the front tires and eliminating the rocker panels ahead of the door openings. The effect recalled the long, sweeping front fenders of 1930s Duesenbergs. Although a daring exercise, the layout left minimal protection to the vertical body sides from road debris and spray flung up by the front tires. These cars highlighted the designer’s never-ending struggle to balance exciting looks with daily practicality.
131 Corvettes and movies went hand in hand from the beginning. The 1967 feature film Hot Rods to Hell was memorable for its inclusion of a modified 1958 Corvette. In the 92-minute drive-in movie classic, a conservative family in a pea-soup-green 1961 Plymouth Belvedere is terrorized by a gang of hooligans driving an assortment of hopped-up machines. Leading the pack is a bright-red Corvette with flamed side coves, yellow racing stripes, Radir mag wheels, a tall roll bar, and deleted front bumper and grille. The Corvette eventually was wrecked in a game of chicken.
132 Alternate titles for the film Hot Rods to Hell were 52 Miles to Midnight and 52 Miles to Terror. Because it was a decidedly low-budget production, it is likely that only one 1958 Corvette was used/destroyed in the making of the film. This assumption is supported by close inspection of the film; the unique flamed graphics and 1958-only ribbed hood and chrome trunk strakes appear identical in every scene. Most action movies involving cars are guilty of continuity lapses (1959–1961 Corvettes doubling for the 1958 hero car, non-exact placement of flame and stripe graphics from one stunt car to the next, etc.), but not this gem.
133 One glance at the 1954 Mercedes-Benz 300SL revealed its heavy influence on Corvette designers. In particular, the GM stylist in charge of the Corvette’s body redesign, Bob Cadaret (supervised by Bill Mitchell), clearly mimicked the German supercar’s ovoid grille opening, arched front bumper ends, and high-set headlamps, not to mention the blatantly copied twin hood blisters. It is not known how the 300SL’s designer, Paul Braiq, felt about the U.S. automotive giant pilfering his design.
Today, the Corvette cannot be mistaken for anything else. In 1956, however, this view had Mercedes-Benz 300SL owners crying foul.
134 At the rear of the body, Cadaret and his team took more cues from the 300SL. Although not as obvious, the rounded, humplike mound created by the deck lid positioned between the fender peaks was adapted from the Mercedes-Benz design. The major difference between the two was Corvette’s glass-fiber construction versus the Mercedes-Benz’s steel shell (with aluminum doors, deck lid, hood, and rocker panels). Photos exist of the Oldsmobile Golden Rocket Motorama dream car posed next to a Mercedes-Benz 300SL gullwing coupe within the GM styling center. A little benchmarking clearly went a long way.
135 Although Arkus-Duntov’s influence began to emerge with the 1956 Corvette, his impact on the 1953–1955 models was minimal. Born in Belgium to Russian parents, the automotive genius began GM employment on May 1, 1953. The Corvette’s path for the next two years was already established, and there was little room for his influence.
136 Arkus-Duntov’s first assignment as a member of Chevrolet’s research and development department in 1953 was to explore varied chassis designs for rear-engine passenger cars. General Motors had been exploring rear-engine test cars for more than a decade, the 1960 Corvair being the eventual manifestation of the program. An early contribution to the solution of tail-heavy vehicle platforms was Arkus-Duntov’s discovery that oversteer and understeer habits could be tuned using tire pressure alone. The Corvair’s unconventional biased factory tire-pressure specification (22 psi front, 26 psi rear) was Arkus-Duntov’s doing.
137 Ed Cole, a man whose motto was “kick the hell out of the status quo,” hired Arkus-Duntov. Cole’s decision to hire the then-43-year-old with the thick Russian accent was highly controversial; Senator Joe McCarthy’s notorious anti-Communist “witch hunts” were in full swing. Many of GM’s more conservative staffers blatantly disliked Arkus-Duntov and his outspoken demeanor. British-born chassis engineer Maurice Olley was particularly critical of Arkus-Duntov’s appointment. However, they eventually developed mutual respect for each other, and both men contributed great things to the Corvette program.
138 Arkus-Duntov’s entrance into the Corvette development program wasn’t the straight shot most enthusiasts assume it was. For many months he toiled on decidedly non-performance projects, ranging from working on the aforementioned rear-engine family-car project to solving vibration problems on two-piece school-bus drive-shafts. The change came in mid-1954 when Ed Cole chose him to help develop mechanical fuel injection for the upcoming V-8 engine program. Yes, that fuel injection, the immortal “fuelie” of 1957.
139 In hindsight, we mostly view Rochester Products Division’s mechanical fuel injection as a high-performance development meant just for the Corvette. However, quite the opposite is true. Although fuel injection generally offers advantages over carburetors in high-performance applications, General Motors also saw fuel injection as a modern technology and marketing bonus worthy of inclusion on family cars. Thus, engineers from Cadillac and Oldsmobile joined Duntov on the fuel-injection program. In the end, Pontiac was the only non-Chevrolet GM division to offer Rochester mechanical fuel injection, available on 447 of its 1957 Bonneville personal luxury models, plus 511 more in 1958 (available on all full-sized models).
140 Although Arkus-Duntov was only 46 years old when he joined the Rochester fuel-injection program in 1955, his prematurely gray hair earned him the nickname “Papa” among his fellow engineers. By then, he had come to terms with his genetic fate. A mere three years earlier, and just days before the 1952 Le Mans race, Arkus-Duntov attempted to force nature’s hand with a hair dye of dubious quality. After turning yellow, much of his hair fell out, which prompted French press agents to nickname him “Le Jeune Blonde,” the young blonde. At the time, he was driving an Allard J2X with a Cadillac powerplant. Arkus-Duntov also drove many European road races for Mercedes-Benz, Porsche, and Talbot.
141 The Rochester mechanical-fuel-injection program bore fruit, but Arkus-Duntov’s desire to be in charge of Corvette development didn’t come to fruition until December 1, 1968! That’s when he became Corvette’s first chief engineer, a position he held until 1975. Before his 1968 appointment, the Corvette didn’t have a chief engineer, and Arkus-Duntov’s title was director of high performance, putting him in charge of projects as varied as the SEDCO 1957 Black Widow circle-track cars and police packages powered by the Super Turbo-Thrust 348, Chevy’s first big-block V-8.
142 Speaking of big-block Chevrolet engines, was the W-series 348 or “so-fine” 409 ever considered for the Corvette option sheet? Yes. Only 2-3/4 inches wider and 1-3/4 inches longer than the small-block V-8, size wasn’t a problem. A handful of 348-powered 1958 Corvette test cars were certainly assembled for evaluation within General Motors. But the somewhat disappointing W-engine didn’t add anything the hotter small-block 283s didn’t already deliver, except some torque and a disturbing increase in mass over the front tires. By the time the 409 arrived in late 1961, Corvette product planners had abandoned any thoughts of using the W-series big-block. But can you imagine how exciting a triple-carbureted 348 or dual-quad 409 factory Corvette engine option would have been? Alas, the world had to wait until March 1965 to sample the first factory big-block Corvette.
143 During the Automobile Manufacturers Association (AMA) racing and performance promotion ban of June 1957 (see Fact 229), Chevrolet canceled many promising and exciting race programs but didn’t exit the racing world entirely. Like several other Detroit automakers, Chevrolet went underground and contracted front organizations to continue performance development during the late 1950s. One of them was the Advanced Marine Corporation (AMC) of Miami, Florida. NASCAR star Jim Rathmann ran the organization, which was conjured up by Arkus-Duntov and GM executives Ed Cole and Vince Piggins and served as a link between NASCAR racers and Arkus-Duntov’s advanced engine group in Detroit. Between 1958 and 1960, General Motors paid AMC/Rathmann more than $100,000 despite the corporate ban. AMC’s efforts focused on improving the 348 W-engine for racing and also on refining chassis, suspension, and brake components for race use. The program bore immediate fruit in the form of satisfying first, second, and third race victories at the all-new Daytona International Speedway in 1959 and a victory by Junior Johnson in the 1960 Daytona 500, all of them won with 348-powered Chevrolet race cars.
144 There’s been a lot of confusion about the Southern Engineering and Development Company (SEDCO) race shop that produced the legendary Black Widow Chevy 150 race cars in 1957. SEDCO was established in Atlanta, Georgia, in the fall of 1956 to serve as a Chevrolet-funded development shop that was located closer to the NASCAR race action than GM’s Warren, Michigan, central offices. SEDCO was indeed responsible for retailing the Black Widow factory race cars of 1957, as well as for supplying Corvette racers on the SCCA road-race circuit. But unlike the Advanced Marine Corporation, SEDCO was not a clandestine organization. In fact, because of its high profile, when General Motors elected to obey the June 1957 AMA performance ban, SEDCO closed its doors.
145 When Advanced Marine Corporation wasn’t secretly helping land-based Chevrolet racers be more competitive, it lived up to its namesake and created engine packages targeted at small-boat owners. One of them was a Corvette 283 small-block-based marine engine that was marketed as “the Terminator.” Decades before “Ahnold’s” android character lit up the silver screen and Ford toyed with using the name on supercharged 2003–2004 Mustang SVT Cobras (19,140 were built, but the name only appeared inside the bolt-on plastic body side scoops), Rathmann’s Miami race shop recognized the inherent “badness” of the Terminator nameplate. Specifics on AMC’s 283 Corvette-themed Terminator weren’t available as of this writing.
146 For all he contributed to Corvette’s legacy and sales, it doesn’t appear that Arkus-Duntov became a millionaire during his years at General Motors. In the spring of 1953 when he was negotiating with GM’s Maurice Olley for a job, documents show that General Motors offered Arkus-Duntov $14,000 per year with the potential to double the sum through GM’s bonus system. Considering that the average American household income was $4,011 in 1953, earning three to six times that amount was attractive. Still, the Arkus-Duntovs rented dwellings until 1956, when they purchased a lakefront home in Grosse Point Shores. The home came with a grand piano that Arkus-Duntov didn’t want. After the now-paid house seller flippantly told Arkus-Duntov to throw it into the lake, Arkus-Duntov did just that. Using an axe, he smashed the piano to bits then tossed the debris into Lake St. Clair. His wife, Elfi, looked on but saved many ivory keys.
147 Only one year into his position at General Motors, Arkus-Duntov’s free-spirited, vagabond nature led him to accept an offer directly from Porsche to drive one of its 550 Spyder factory team cars at the 1954 24 Hours of Le Mans race. Although Porsche wasn’t concerned about having an American GM employee drive one of its cars in competition, Arkus-Duntov faced the touchy job of requesting permission from Ed Cole and Maurice Olley, his superiors at General Motors, to do so. At the time, the Porsche engineering department openly sought R&D contracts from other carmakers (and still does), so Arkus-Duntov couched his request by saying that he’d visit Porsche’s suspension lab for possible ideas and collaboration on future independent-rear-suspension projects (which resulted in the swing-axle setup used on the 1960–1964 Corvair). Cole and Olley reluctantly granted Arkus-Duntov permission to go, and General Motors covered his pay and personal expenses! Arkus-Duntov and French co-driver Gustav Olivier expertly navigated the 8.3-mile Le Mans circuit for the 24-hour period to win the 1.1-liter class while also finishing 14th overall and 14th in the Index of Performance.
148 In 1955, Arkus-Duntov did it again! For the 1955 running of the 24 Hours of Le Mans, Porsche once again invited Arkus-Duntov to don his string-back driving gloves and pilot another Porsche 550 Spyder in the prestigious endurance race. With co-driver Auguste Veuillet, Arkus-Duntov again won the 1.1-liter class and placed 13th overall and 10th on the Index of Performance. Zora’s accomplishment wasn’t heralded in Chevrolet magazine ads of the day (he was at the wheel of a Porsche, after all), but the Chevrolet engineering department’s in-house newsletter Engineering News did acknowledge the feat with a written pat on the back. Arkus-Duntov’s stock as the right man to lead Corvette’s performance development was affirmed by his racing exploits.
149 In 1956 Arkus-Duntov filed for and received three U.S. patents for designs and components he created for the Rochester fuel-injection system. Although I don’t know the specific details of Arkus-Duntov’s arrangement with General Motors, in terms of compensation, as employees of employers, such patents don’t always result in financial gains for the holder.
150 Messy but true: From 1956 through mid-1960, the stainless-steel VIN tag was fastened to the driver-side doorjamb, just below the upper hinge, with a pair of Phillips-head screws. To deter tampering, the slots in the screw heads were filled with resin. When the resin cured, access to the drive slots was denied, making VIN tag removal impossible through normal means.
151 Corvette received roll-up door glass in 1956, an improvement that quieted loud customer complaints about the awkward snap-in side curtains used previously. Better still, RPO 426 delivered power window lifts for $64.60. Only 547 of the 3,467 cars built in 1956 were so equipped.
152 An optional power-operated folding top augmented the standard manual folding top, adding to Corvette’s more civilized 1956 redesign. For $107.60, RPO 473 took the hassle out of raising and lowering the vinyl roof in case of rain. A healthy 2,682 out of 3,467 1956 Corvettes came with the power top.
153 Snuffing out a lucrative cottage industry that sold fiberglass lids to chilled 1953–1955 Corvette owners, Chevrolet finally released its own auxiliary hardtop in 1956. For $215.20, buyers could have RPO 419, a color-matched fiberglass roof that could be installed or removed in minutes. The combination of the hardtop and the new roll-up door glass finally transformed the Corvette into an all-weather machine. Of the 3,467 cars built in 1956, 2,682 came with the auxiliary lid.
154 Interestingly, Chevrolet knew that a certain number of customers saw the folding roof as being superfluous after the RPO 419 hardtop arrived. Thus, customers who knew they’d never hassle with the soft top could get the hardtop at no charge (a savings of $215.20). Corvettes built this way lacked the folding top and related anchoring hardware that was otherwise stashed in the area behind the seats. This was popular with road racers because it shed about 40 pounds, and 629 Corvettes were built this way in 1956. This roof-substitution option continued through 1962.
155 A major boost to passenger comfort came in 1956 when the RPO 101 heater was redesigned to blend fresh outside air into the mix, putting an end to the stuffy atmosphere of older cars. The improved equipment triggered a price increase from $91.40 (1955) to $123.65. That said, availability delays forced the factory to install the old-style non-recirculating heater in the first 145 1956 models built.
156 Even though virtually every restored 1956–1961 Corvette seen today has a two-tone, contrasting paint treatment applied to the side cove, the attractive feature was not standard issue. Rather, buyers had to request RPO 440 to get the contrasting cove paint, which cost an extra $19.40 ($16.15 after 1957).
157 Don’t assume that every 1956–1961 Corvette came with the RPO 440 contrasting-paint cove treatment. In fact, far more new Corvettes from that era were delivered with monotone paint than with two-tone. In 1956, 2,208 of 3,467 cars built came with monotone paint. In 1957, 3,545 of 6,339 cars built had monotone paint. Of the 9,168 cars built in 1958, 5,746 came with monotone paint. For 1959, 6,739 had monotone paint out of 9,670 cars built. In 1960, 6,949 of the 10,261 cars built came with monotone paint. Finally, in 1961, of the 10,939 cars built, 7,588 had monotone paint. Clearly, the two-tone side-cove treatment was not as popular then as it is today.
158 The two-tone side-cove paint option was dropped in 1962, Corvette’s final year before the arrival of the Sting Ray. Given the facts presented above, Chevrolet’s decision makes sense. If the majority of buyers don’t want something, why offer it? As such, all of the 14,531 Corvettes built in 1962 had monotone paint. The RPO 440 two-tone cove paint treatment was discontinued.
159 Even though the 1962 Corvette was a last-run offering, Chevrolet made several changes, including eliminating the previous bolt-on stainless side-cove outline trim. In its place, an exaggerated, raised lip was formed into the fiberglass. Thus, the door skins and front fenders were unique to the 1962 Corvette.
160 Unlike the rectangular-screen radio antennae molded into earlier trunk lids, a telescoping mast-type antenna was adopted for 1956-on. But unlike the conventional placement atop the passenger-side front fender, it was mounted atop the driver-side rear quarter panel. This added distance worked with the metal ignition-system shielding to prevent radio interference.
161 Speaking of radios, they were a $145.15 mandatory option from 1953 to 1955; buyers were finally able to decline radio equipment starting in 1956. Typically requested by road racers who didn’t need the added entertainment, Corvettes built without factory radios came with rectangular block-off plates to seal the hole left in the dash. Radio-delete Corvettes also lacked the elaborate multi-piece stainless-steel ignition shrouding.
In 1956, the mandatory installation of radio equipment ended. Of the 3,467 cars built that year, 750 omitted the radio and carried a color-matched metal block-off plate, instead.
162 Savvy Corvette spotters could learn what was under the hood by checking the tachometer face. Cars equipped with the hot solid-lifter engines displayed higher RPM ceilings. Generally speaking, the dual-quad and fuelie tachs had an 8,000-rpm ceiling, while lesser mills went to 6,000 rpm. For comparison, the earlier 6-cylinder tachs of 1953–1955 (seven built) only went to 5,000 rpm. The 1955 V-8 tachometer read to 6,000 rpm.
163 One exterior item that quietly appeared in 1956 was a pair of chrome door handles. It’s often forgotten that 1953–1955 Corvette bodies lacked them.
164 Despite the juggled lengths of the tailpipe tips, 1953–1955 Corvettes suffered from exhaust staining on the body. Arkus-Duntov affixed tufts of wool to the area and discovered that repositioning the exhaust tips to the ends of the fenders eliminated the staining. The body stylists further developed the idea by designing the rear bumpers to surround each exhaust tip.
165 Although the relocation of the exhaust outlets spared the paint from staining, the noxious fumes were known to attack the chromed bumper surrounds used on 1956–1960 models. Win some, lose some. The 1961 Corvette’s exhaust outlets were the first not to be accentuated by chrome tips or to be incorporated into the bumpers. In fact, a close look at any unrestored 1961 car (or correctly executed restoration) reveals that the terminus of each pipe was subtly flared to hide behind the silhouette of the lower body panel, an odd change of theme in those days when dual exhaust outlets were a major status symbol.
166 The hide-away tailpipe configuration was continued for 1962. Interestingly, even though the 1961–1962 duck-tail quarter panel and taillamp panel treatment provided a glimpse of the 1963 Sting Ray’s styling, the actual Sting Ray returned to the loud-and-proud exposed-tailpipe format.
167 Reflecting a strong commitment to Corvette’s future after some very iffy years, Chevrolet totally redesigned the 1958 instrument panel and dashboard with a more intimate, cockpit-like style. A central “waterfall” divided the space under the dash and moved the radio and heater controls away from the dash face. Passengers now had something to hang onto in the form of a padded grab bar.
Previewed on the 1956 Pontiac Club de Mer Motorama show car, the deep, crescent-shaped driver and passenger cutouts rolled out in 1958.
168 The 1958 interior restyle brought a functional touch that arrived just in time for the high-revving solid-lifter engines made available: a properly positioned tachometer. Mounted directly in the driver’s line of sight, its large numerals were easy to read and react to. The previous tachometer location in the center of the instrument panel was pleasingly symmetrical but a functional disaster. One wonders how many 1956 and 1957 Corvette engines were scattered by drivers unable to see when redline was near.
169 1957 Corvettes equipped with the RPO 579E option provided an exception to the goofy tachometer placement of pre-1958. This option was an all-out competition package featuring the Rochester fuel-injected 283 and a mechanically driven tachometer strapped atop the steering column directly in front of the driver. This tach’s 8,000-rpm face hinted at the potent 283’s true capability. The standard (and useless) tachometer was deleted. Filling the empty hole was the same circular Corvette nose and deck-lid emblem used on 1957 Vettes. Only 43 legitimate RPO 579E Corvettes were built (the option cost $726.30), most of which were sadly raced into the ground.
170 Although the external details are seemingly identical, 1957 Corvette bodies differed significantly from 1956 bodies due to stamped-metal reinforcement panels and braces added inside the doors, beneath the cowl, and atop the rocker panels. Given equal treatment, storage, and use, a 1956 body exhibited more stress cracks than a 1957-or-later body due to its lack of these bonded reinforcements.
171 Something new appeared on the shift handle of 4-speed Corvettes in 1959: a chromed reverse-lockout T-handle located between the boot and the ball. Spring loaded, it prevented accidental engagement of Reverse gear unless the driver deliberately lifted the T with his fingers. Of the 9,670 Corvettes built in 1959, 4,175 were 4-speeds. Interestingly, 1959 marked the first year that 4-speed transmissions were available in Chevy full-sized passenger cars, but their spindly swizzle-stick shift handles lacked a reverse-lockout function until 1964.
172 Arkus-Duntov always considered safety a priority, having seen his share of tragic racing accidents. In 1955, Arkus-Duntov was racing a Porsche 550 Spyder at Le Mans (see Fact 148) when Pierre Levegh’s Mercedes-Benz 300SLR crashed into the grandstands, killing him, 80 spectators, and the Mercedes-Benz factory race program for many years.. In 1958, Corvettes arrived from the factory with seat belts as standard equipment, almost a decade before federal mandates forced their inclusion on other Chevrolets and the entire auto industry.
173 Body-color-painted headlamp trim rings easily identify early 1956 Corvettes. Intended to stretch the appearance of the front fenders, the applied paint was highly prone to chipping. Within a month of startup, General Motors reverted to the bright, chrome-plated rings used through the 1957 model run.
174 In January 1957, a vented gas tank was added to the Corvette to prevent vapor slosh and surge on hot days. To accommodate the rubber fume-exhaust tube, a small exit hole and rubber grommet was added next to the fuel filler and gas cap. It was all positioned beneath the hinged fuel flap adjacent to the driver-side door. As was the case in 1953–1955, the 1956–1962 fuel-flap door was made of metal, not fiberglass.
175 In 1957, Corvettes painted Inca Silver previewed a new paint formulation that all GM divisions would adopt beginning in 1958. To support the metallic content of Inca Silver (and the growing overall trend toward metallic paint), nitrocellulose lacquer replaced GM’s age-old nitrocellulose paint. The rest of the 1957 Corvette color palette relied on nitrocellulose for that final year. Only 65 of the 6,339 Corvettes built in 1957 wore Inca Silver paint. Enamel paint was used universally on virtually all GM wheels (Corvette included) because of its durable nature.
176 Although maligned today and during the supercar 1960s, 3-speed manual transmissions were a treat when they finally appeared in 1956. Of the 3,467 cars built that year, more than half had clutch pedals. The remainder carried the cast-iron Powerglide 2-speed automatic, a $188.50 option.
Chevy finally put some sport in its sports car with the mass availability of 3-speed manual transmissions in 1956. Chevrolet put the shift quadrant on the trim plate instead of the shift ball.
177 It’s impossible to do an oil-and-filter service on a 1955 V-8 Corvette. Oil, yes; filter, no. That’s because all 1955 V-8 engine blocks lacked provisions for an oil filter. For passenger cars, the AC company offered an add-on filter unit, but because it mounted tall, atop the intake manifold, it didn’t fit under the Corvette’s low-profile hood. For 1956-on, the block was redesigned with a circular pad at the rear of the driver-side oil-pan rail to accept a canister-style filter unit. Thus, filters became standardized on V-8s of every displacement for 1956-on.
178 The V-8 returned with a bigger splash in 1956. An optional dual-quad induction system was offered instead of the already-impressive single 4-barrel carburetor fitted to the 1955 Corvette. Incredibly, the vast majority of 1956 Vettes (3,080 out of 3,467 cars, about 85 percent) received the RPO 469 and its sexy dual Carter WCFB 4-throat carbs, despite the $172.20 upcharge.
179 The 1956 RPO 469 dual-quad 265 V-8 marked Corvette’s first use of an aluminum intake manifold on a V-8. The extra breathing helped boost output from 210 to 225 hp. The base-Corvette V-8’s single Carter WCFB 4-barrel was bolted to a cast-iron intake manifold.
180 Fuel injection was added for 1957, but unlike the modern electronic-fuel-injection (EFI) systems we use today, the Ram Jet fuel-injection unit was mechanical. That is, instead of having an electric fuel pump and electronically cycled solenoid-style injectors, the pump was driven (at half engine speed) by a cable attached to the ignition distributor housing. The injectors were simple nozzles inserted near the base of the manifold runners and were always open for a constant-flow system.
181 With the mechanical fuel pump driven by the distributor shaft, it delivered fuel pressure the entire time the engine was running. A three-piece bypass valve assembly regulated the pressure of fuel delivery. An air meter sensed engine vacuum (throttle position) and signaled the pressure regulator to direct full fuel flow to the nozzles (for power) or return some of it to a reservoir (light load, idle). Fuel pressure ranged from about 3 psi to 200 psi.
182 The primary goal of the Rochester fuel-injection system was to eliminate the fuel-slosh problem encountered with carburetors on road-race circuits. All Corvette carburetors relied on integral reservoirs (called bowls) to maintain a steady supply of gasoline, ready to be drawn into the engine by vacuum. However, during hard corners, lateral g-forces could pull the raw gasoline away from metering orifices and cause fuel starvation and power loss/stalling, not the way to win races. With its constant, pressurized flow, mechanical fuel injection (and modern EFI) was a solution.
183 Although GM’s primary goal was improved road-race results, it just so happened that fuel injection, with its (potentially) more precise fuel metering, could also improve fuel economy, reduce tailpipe emissions, and eliminate the cold-start hassles involved with certain carburetors and choke assemblies. A properly tuned Rochester fuel-injected Corvette (offered from 1957 to 1965) generally gave better fuel economy than its carbureted siblings and started more easily on frigid mornings.
184 Airflow passing through the large, single venturi air meter gave fuelie Vettes a characteristic whistling sound at idle and during low-speed cruising. It was a detail that frustrated certain fuel-injection owners hoping to lurk undetected on the stoplight drag-racing circuit. They could remove the emblems, but the sound gave them away.
185 Another benefit that General Motors took advantage of when designing Rochester fuel injection was how the system allowed for the benefits of ram tuning to be harnessed. On virtually every reciprocating engine using intake ports and runners to deliver the fuel-air mixture to the backs of the intake valves, there exists the opportunity to manipulate the incoming column of fuel for enhanced performance. Because this column is rushing toward the intake valve at 1,100 feet per second when the engine is at 6,000 rpm, it contains energy. If the length, volume, and shape of the intake runner and port are manipulated, the amount of energy in this slug of incoming fuel air can be harnessed for a mild form of supercharging. Chrysler adopted the ram-tuned intake-manifold concept in 1960 on everything from the Slant Six Valiant to the mighty Chrysler 300F. But in 1957, only Chevrolet (and Pontiac’s FI Bonneville) were using the ram-tuning concept on regular production models.
186 The ram-tuning magic happened in the unique dog-house upper intake manifold atop every Rochester FI Corvette engine. Arkus-Duntov and the Rochester engineers wanted to boost the 283’s modest low-end punch, and they calculated that 11-inch-long runners would do the job. These runners were present inside every Rochester dog house but were only visible on 1963–1965 fuelie units. Rochester redesigned these later plenum boxes with a two-piece construction. Unscrewing the lid allowed inspection of the ram tube inlets.
187 1961 brought a significant weight reduction for 4-speed buyers in the form of a new cast-aluminum transmission case for the Borg-Warner T-10. Although it was relatively unchanged internally, switching from cast iron shed about 30 pounds. The base cast-iron 3-speed manual transmission was never upgraded with an aluminum case and remained this way through its discontinuation after 1969.
188 The 2-speed Powerglide automatic transmission also underwent a serious diet in 1962. GM’s Hydramatic division invested millions to switch from cast-iron to aluminum construction, which was a key component of Chevrolet’s all-new Chevy II/Nova compact car (in which weight was minimized). Corvettes benefitted from a 50-pound weight reduction.
189 1960 brought lightweight aluminum construction to the clutch housing on 3- and 4-speed manual-transmission cars and the radiator unit on dual-quad and fuel-injected applications. Although replacing the traditional brass-and-copper radiator shed nose weight for improved handling, the lighter clutch cover was a mixed bag. After removing the stronger cast-iron case surrounding the spinning flywheel and pressure plate all that remained between flying clutch debris and the passenger compartment was a thin fiberglass floorboard. Serious Corvette racers quickly adopted aftermarket blow shields for improved safety.
190 Another aluminum item planned for 1960 that never materialized in dealer showrooms were the much-celebrated RPO 579/579D aluminum cylinder heads. Numerous enthusiast publications sang their praises, and official Chevrolet sales literature even announced them. British industry publication The Autocar reported in its December 25, 1959, issue that casting flaws were the killer, saying, “Heads tend to crack around (rocker arm) stud bosses. On a recent production run they got only two good heads out of 140!”
191 Before 1962, carbureted Corvette engines used a generator-mounted cable to drive the tachometer. In contrast, most fuel-injected cars fed the tach from a cable run by the distributor. The trouble with the generator-driven tachometer was that a loose fan belt caused slippage. Precise, instantaneous monitoring of crankshaft speed was not possible with a slipping fan belt. Chevrolet corrected the situation in 1962 by upgrading all Corvette engines to distributor-driven tachometers.
192 The fuel-injected 1957–1961 Corvettes built with generator-driven tachometers were the milder versions. With their lower compression ratios, relatively conservative cams, and hydraulic lifters, rapid RPM surges weren’t as much of a threat as they were with the top-tier fuelie engines, whose elevated compression ratios, more radical cams, and high-revving solid lifters more easily slipped fan belts, sending delayed and inaccurate engine RPM info to the driver. Moreover, 1961 was also the first year Chevrolet barred the mating of fuel-injected engines and Powerglide automatic transmissions. From 1961 to 1965, every fuelie was backed by a manual transmission.
193 The 3-speed manual transmission offered for the first time on 1955 Corvettes was not a derivative of the Muncie 318/319 unit used in passenger cars since 1940. Rather, it was manufactured by GM’s Saginaw Gear division and featured unique ratios of 2.20:1, 1.30:1, and 1:10. Passenger cars from 1955-on (also) using this new transmission were equipped with 2.94:1, 1.31:1, and 1:10 ratios. The 2.20 First gear ratio offered less torque multiplication than the 2.94:1 passenger-car ratio but was offset by the Corvette’s 500-pound-lighter mass. The benefit of the 2.20:1 Low-gear ratio was that it suffered less of the RPM drop encountered during upshifts, and thus kept the engine closer to its power band when driven with a heavy throttle foot. Of the 3,467 Corvettes built in 1956, only 1,878 were equipped with this new 3-speed manual. Unfortunately, this new transmission lacked synchromesh in First gear.
194 All 1953–1955 Corvettes came with a 3.55:1 rear-axle ratio, regardless of engine or transmission. For 1956–1961, the 3.55 ratio was standard only with the Powerglide automatic. For 1961, manual-transmission-equipped Corvettes came standard with slightly deeper 3.70:1 gears to bolster off-the-line torque multiplication. Optional rear-axle ratios also arrived in 1956 and included 4.11 and 4.56 ratios. For reasons unknown, the overdrive-equipped 3-speed stick available on passenger cars was not available in Corvettes. Although acceleration with 4.11 or 4.56 gears was thrilling, highway cruising at 3,800 rpm could be loud and tiresome. In 1961, a 3.36:1 gear-set option arrived for buyers less concerned with acceleration than with calm highway cruising and improved fuel economy.
195 In 1962, the standard 3.55:1 rear-axle ratio was changed to 3.36:1 because the new 327 delivered an average of 50 extra ft-lbs of torque. Thus, 3.36:1 gears appeared as standard equipment with all engines except for the top-tier, solid-lifter 340-hp (RPO 396) and 360-hp (RPO 582) fuelies. The only exception to the 3.36:1-ratio rule came when the 340- and 360-hp engines were coupled to the 4-speed manual transmission (and most were). Then the standard axle ratio was 3.70:1. The torque-laden 327 also opened the door to Corvette’s highest ratio (low numeric) to date, a 3.08:1 gear set, which was available with all versions of the new 327.
196 The Corvette’s small-block engine was offered in four displacements, 265 (1955–1956), 283 (1957–1961), 327 (1962–1968), and 350 (1969–1996). Unlike the practice employed in the passenger-car lines, where different sizes were offered optionally, Corvettes always came with the largest displacement offered for that particular model year. By contrast, Corvette’s early nemesis, the 1955–1957 Ford Thunderbird, forced buyers to pay extra for larger engines. In addition, unlike Thunderbird, which offered a lowly 2-barrel carburetor on base models, even the most inexpensive Corvette model was fitted with a 4-barrel carburetor and dual exhaust.
197 An open, unshielded distributor cap and wires in any early Corvette can only mean one thing: radio delete. Because the fiberglass firewall didn’t block electronic interference from the receiver and antenna, radio-equipped cars required elaborate stainless steel and chrome-plated stamped-tin shrouding.
The exposed wiring won’t cause any radio static on this Corvette because it was born without a radio. To save a few manufacturing dollars, radio delete Vettes didn’t carry the shielding. Notice the unused screw holes and mounting tabs on the spark-plug wiring loom. The same bits were used in either case.
198 Proving that racing improved the breed, the 1957 model year brought the much-needed Posi-Traction limited slip differential to Corvette’s option sheet. It answered the need for a means of preventing wheel spin on hard acceleration and cornering that was apparent from the start of Corvette’s existence in 1953. After validation aboard 1956 factory Corvette race-team cars, the clutch-type differential was recognized as the best type for mass production. Unlike the harsh on/off ratcheting differentials tested by Arkus-Duntov’s minions at the racetrack and proving grounds alike, the spring-loaded clutches placed within the differential case engaged gently and sent equal power to both rear tires. Chevrolet also added Posi-Traction to the passenger-car option sheet in 1957, and a legend was born.
199 General Motors rightfully recognized Posi-Traction as a technological advance worth bragging about. Just as its Rochester fuel injection warranted special chrome fender emblems, General Motors came up with metal badges touting the presence of Posi-Traction, but with a twist: The badges were applied to the dashboard, inside the vehicle, where the only people impressed were the passengers. Also, these badges were only installed on regular passenger cars, not on Corvettes. Used only on 1958–1959 passenger cars, the dash-mounted Posi-Traction emblems were gone by 1960 and, surprisingly, never reappeared, not even aboard such muscular performers as the Chevelle SS396, Camaro Z/28, or Impala SS427. The Beach Boys immortalized GM’s clutch-type limited slip differential in a 1962 song with the lyrics, “She’s my 4-speed, dual-quad, Posi-Traction 409.” The only other Detroit automaker to establish metal emblems for its limited-slip-differential-equipped vehicles was Studebaker. From 1958 to 1963, cars and pickups with Twin Traction limited-slip equipment each bore a one-piece chrome emblem affixed to the tail panel. The emblem consisted of twin, interlocked circles with a bold letter T at the center of each. The TT stood for Twin Traction. To my knowledge, Detroit automakers did not otherwise tout limited-slip differentials in the Corvette years.
Found inside a triple-carbureted 348-powered 1958 Biscayne, this Posi-Traction dash badge hinted that twin strips of burnt rubber were just a foot stomp away. But did Corvette passengers ever see this emblem? See Fact 199 for the answer.
200 Although no Corvette ever wore blatant Posi-Traction badging, Posi-equipped models contained warning stickers with bright red letters on a white background affixed to the underside of the deck. These stickers warned owners not to change flat rear tires with the engine running and the transmission in gear because the limited-slip unit was capable of energizing the tire in contact with the ground and driving the car off the jack. The only other externally visible markings found on 1957–1962 Corvettes equipped with Posi-Traction were a circular metal tag fastened to the lube-filler plug alerting the need for a friction-modifying oil additive and an integrally cast letter P (for Posi-Traction) featured on the driver’s side of (most) 1957–1962 center sections. The lettering of the P was machined differently and also appeared on Chevrolet passenger cars equipped with Posi-Traction. Many say Chevrolet squandered the opportunity to bring even greater recognition and fame to Corvette by ignoring the Posi-Traction advancement.
201 The open-face/open-tail rear axle housing used on 1953–1955 models was replaced in 1956 by a new housing that eliminated the bolt-on inspection cover. The new housing made its debut a year earlier on 1955 Chevy passenger cars and featured a welded-on rear cover, also known as a removable carrier, for extra strength in the brave new world of V-8s.
202 A detail that Arkus-Duntov and the Corvette development team struggled with through 1962 was General Motors’ decision not to share the 1955 passenger car’s modern ball-joint front suspension with the Corvette. Budget constraints mandated the continued use of the kingpin front suspension used since 1946 on passenger cars. Lacking the anti-dive geometry designed into the 1955 configuration, Corvette road racers waged an uphill battle through the live-axle years.
203 To tame the Corvette’s tendency to wander when driven at speed on long stretches of highway, Arkus-Duntov altered the 1956 front suspension to deliver 2 degrees of positive caster. At the time, General Motors designed its passenger cars with neutral caster (zero kingpin angle inclination) to make low-speed steering easier in those days before the mass availability of power assist. Oddly, even though the totally redesigned full-sized Chevy passenger cars switched to modern Glide Ride ball-joint front suspensions in 1955, the crude kingpin front suspension remained under the nose of every Corvette built until 1963.
204 Around back, Arkus-Duntov tailored the rate of the rear leaf springs and shock absorbers to reduce roll understeer from 1956-on. Maurice Olley’s original layout (used on 1953–1955 models) positioned the rear-leaf-spring mounting points so that the leading ends were considerably lower than the trailing ends (as viewed from the side and compared to the horizontal plane). This was done so that with every degree of body roll during cornering the rear axle yawed .15 degrees, effectively counter-steering against the front tires and reducing the tendency of the tail to swing out. Arkus-Duntov changed the spring-hanger locations and reduced Olley’s 15-percent roll-understeer setting to better match the neutral roll steer of the front suspension. The relationship between the roll-steer behavior of the front suspension and that of the rear suspension is referred to as the roll couple. For proper handling, it must be well matched.
205 Despite the significant gain in power in 1956, the 11-inch four-wheel drum brakes of 1955 remained unchanged. However, thanks to GM-sanctioned race efforts in 1956 at Daytona, SCCA road races, the Pikes Peak hill climb, and other venues, a variety of severe-use brake and suspension options arrived in 1957. Every year since, Corvette engineers have included severe-use options to suit virtually every performance need.
206 To announce to the motorsports world that Corvette had arrived and was looking for action, Chevrolet entered the most visible sports-car event held in the United States, the Sebring 12-Hour Endurance Race held in Florida on March 24, 1956. Unlike Daytona, where most of the competitors were amateur hot rodders, Sebring was an SCCA event that brought factory-backed entries from Ferrari, Jaguar, Aston Martin, Porsche, and others. It was the Big League. Four new Vettes were entered, each carrying prototype examples of heavy-duty components that later joined the option sheet.
207 Chevrolet retained racing legend Smokey Yunick and his Daytona, Florida–based Best Damned Garage in Town to help with the early race programs. Despite finishing 15th overall (the top five finishers were Ferrari, Ferrari, Jaguar, Aston Martin, and Maserati), the fact that Corvette even finished the grueling 12-hour event was impressive. Chevrolet’s ad agency, Campbell Ewald, made the most of things, delivering the classic “Real McCoy” magazine ad that appeared in the July 1956 issues of Hot Rod and Road & Track. It was Corvette’s first of many magazine ads touting race success.
208 Supporting the adage that racing improves the breed, the finned brake drums and metallic brake linings used on the 1956 Sebring race cars became part of 1957’s RPO 684 heavy-duty racing suspension option. In addition, RPO 684 also included turbine-like air deflectors placed inside the drums to circulate cooling air, open-faced front backing plates with flexible “elephant-ear” air scoops to force air into the drums, rear-brake cooling ducts, high-rate springs, shocks, and 15 × 5.5-inch steel wheels. Priced at $780.10 (1/4 of the cost of the car), only 51 of the 6,399 Corvettes built in 1957 were so equipped.
209 The RPO 684 big-brake option returned for 1958 with a cool twist. The restyled fascia for 1958 models included a pair of large fighter-jet-inspired air intakes below the quad headlamps, obviously the work of Bill Mitchell’s aircraft-fixated mind. Purely ornamental, they were blanked off for practical reasons, with flat-black paint applied to hide the flat dead ends a few inches inboard. However, with the RPO 684 option, the intakes were trimmed open to feed air to the rear brakes. Huh? Remember, the front brakes used flexible elephant-ear air scoops to direct passing air into the vented backing plates. To get airflow to the rear drum brakes, the grille-mounted intakes fed air into fiberglass conduits mounted to the underside of the front fender and leading down into the hollow rocker panels beneath the doors. From there, the moving airstream was released from the ends of the rocker boxes into square outlets that shot the air into smaller air scoops affixed to the rear-brake backing plates.
210 The 1958 RPO 684 big-brake package required extensive specialized work. Not only did assembly workers have to carefully trim out the fake air intakes under the headlamps, but they had to mount the ductwork to the undersides of the fenders, cut access holes in each end of the rocker boxes, and glass in the square outlets feeding the rear drums. Still priced the same $780.10 as the simpler 1957 setup, 144 were built.
211 If the 1958 Corvette nose’s decorative twin air intakes were perfectly suited for transformation into the RPO 684’s functional brake air-feed ducts, then what about the 1957 big-brake package, where did its rear-brake cooling system ingest air from? Lacking the 1958’s ersatz nostrils, engineers mounted two conical inlet scoops behind the teeth of the simpler 1957 grille. These fed air into 4-inch-diameter flexible hoses that ran along the inner fenders then down to each rocker panel. Once delivered to the rocker panel, the rest of the system rearward to the drums shared the 1958 layout.
212 For 1959, Chevrolet again offered the RPO 684 Heavy-Duty Racing Suspension option, but (except for a handful of early cars) it eliminated the troublesome brake-cooling ductwork and lowered the price from $780.10 to $425.05. Surprisingly, despite the more affordable price, demand remained flat, with 142 takers, two less than 1958 (when 144 were sold). In all instances (the big-brake equipment was offered from 1957 through 1962), the “elephant-ear” air scoops were shipped loose in the trunk for dealer or customer installation.
213 In 1959, all Corvettes were equipped with tubular steel traction bars. Mounted to the top of each end of the rear axle housing and running forward to the articulated frame mounts, they reinforced the front halves of the leaf springs to combat spring wrap-up and axle tramp on hard acceleration and braking. Before Chevrolet added them to all 1959s (regardless of power rating or transmission), companies such as Traction Master made small fortunes selling similar devices to owners of older Corvettes.
214 Proving that bigger isn’t necessarily better, the Cerametallic brake linings used in Corvette’s optional brake packages had less contact area with the drums than the standard organic brake linings. The drop from 158 to 112.5 square inches was due to 1-inch gaps between the friction blocks. Intentionally added by Bendix engineers, they improved heat dissipation and reduced glazing and were also seen on the brake shoes used in NASCAR superspeedway race cars until the advent of disc brakes.
215 Although real knock-off wheels didn’t arrive until 1963, for 1956, the vague suggestion of two-bar knock-off spinners evolved into very realistic-looking copies. These hefty items were affixed to Corvette’s various stamped stainless-steel (snap-on) wheel-cover designs through 1962. Interestingly, Chevrolet adapted the cast-metal spinners for use on passenger-car wheel covers and even for those used on the Corvair Monza. The key difference was that only Corvette-sourced spinners were marked “Chevrolet Corvette.” Others repeated the “Chevrolet” nameplate twice.
216 Arkus-Duntov undoubtedly flinched at Corvette’s simulated knock-off wheel covers. It is ironic that 1957–1962 Corvettes equipped with the optional big-brake packages or the RPO 276 15 × 5.5-inch steel wheels (15 × 5-inch wheels were standard) were stuck with the same austere hubcaps fitted to 6-cylinder 150s and Biscaynes!
217 When the RPO 276 15 × 5.5-inch rims were specified, Chevrolet ensured that the spare tire was mounted to a matching rim, as well. This eased tire rotation. RPO 276 order rates were never high and amounted to 51 in 1957, 404 in 1958, 214 in 1959, 246 in 1960, 337 in 1961, and 561 in 1962.
218 Whitewall tires are commonly installed on restored Corvettes today, but how common were they originally? They were a mandatory option from 1953 to 1956; in 1957 the customer finally had a say in the matter. The 6.70-15 whitewalls added $31 to the total price and were taken by 5,019 out of 6,339 buyers in 1957, 7,428 out of 9,168 buyers in 1958, 8,173 out of 9,670 buyers in 1959, 9,104 out of 10,261 buyers in 1960, and 9,780 out of 10,939 buyers in 1961. In 1962, fashion changed; a thinner, 1-inch-wide band replaced the wide white stripe. Take rates for whitewall tires are not known for 1962 at this time.
219 In these days of exotic hydro-formed frame rails, forged-aluminum suspension control arms, carbon-ceramic brake rotors, and plastic-based leaf springs, it’s shocking to learn that Chevrolet relied on simple metal shims to revise the Corvette’s front-suspension geometry in 1956. Positioned between the front control arms and their mounting points on the front frame rails, these simple stamped-steel shims added much-needed caster for improved handling.
220 In 1957, Chevrolet used another basic device, a simple, flat, steel steering adapter, to improve steering response. The same steering box and pitman arm remained, but an extension was clamped to the center steering arm at the frame crossmember. The altered pivot points changed the steering ratio from 21:1 to 16.6:1. Only 3.7 turns were needed to go lock to lock, but the setup increased steering effort during parking maneuvers so much that General Motors restricted installation only to cars ordered with the RPO 684 heavy-duty brake and suspension option.
221 The first wheel-cover redesign in three years was in 1959. Although it was almost identical to the pressed stainless-steel units used since 1956, the flat span between each of the 10 “spokes” was pierced with a 2.0 × .5-inch rectangular vent. It may sound laughable in our modern world of aluminum and even carbon-fiber wheels, but the 10 vents eliminated the heat-trapping effect of previous non-pierced, full-sized wheel covers. Working with the four air gaps formed by the union of the wheel spyder and hoop, the heat generated by the brake drums finally had free passage to the outer face of each wheel. That said, the big-brake and 15 × 5.5-inch wheel options continued using the small passenger-car center caps, which provided unrestricted airflow to carry away brake heat.
222 One iconic sports-car detail that Corvette never pursued was wire wheels. Installed as original equipment on many British and Italian icons such as the Jaguar XK120, MG TC, and Ferrari 250GT, wire wheels lacked the brute strength to handle the Corvette’s torque-rich V-8 engines. Although the extra spokes bolstered strength, the added mass quickly neutralized any benefit in unsprung mass. Although several Corvette show cars were fitted with wire wheels, they were never offered as a factory option.
223 German sports-car manufacturers Porsche and Mercedes-Benz also largely ignored wire wheels on their production offerings, as well as on their factory-sponsored race cars from the 1946–1962 era. Instead, their sports cars (550 Spyder, 356, 300SL, etc.) used wheels made of steel, aluminum, or magnesium. And while Corvette hesitated until 1963 before offering optional aluminum wheels (with the controversial P48 knock-off wheel option; see Chapter 3), Corvette racers seeking improved power-to-weight ratios turned to aftermarket wheel makers such as Halibrand. In fact, Arkus-Duntov himself turned to Halibrand magnesium wheels for the 1957 Corvette SS race car (aka the XP-64).
224 The 1957 Corvette SS factory race car marked the first appearance of the SS nomenclature on any Chevrolet vehicle. Destined to be immortalized on subsequent, and beloved, offerings such as the Chevelle SS396, Impala Super Sport, Monte Carlo SS, Camaro SS, and many others, it is surprising that Chevrolet never offered the Corvette with the fabled Super Sport script and performance-/image-boosting items. The Corvette SS was strictly an in-house engineering mule that competed in professional race events before the implementation of the June 1957 AMA performance ban.
225 Posi-Traction was a controversial option when it first appeared in 1957 amid the murky clouds of the AMA performance and racing ban. Although it was meant to deliver power to both rear tires, the resulting tail-happy burnouts weren’t conducive to the anti-racing theme of the day. To soften the message, Chevrolet took pains to suggest that Posi-Traction was aimed at making travel safer during snowy winter weather. Although Corvettes and snow went together like submarines and screen doors, buyers quickly registered the Posi-Traction message. Ever-growing buyer take rates completed the story: 1957 = 2,099 out of 6,339 cars, 1958 = 4,011 out of 9,168 cars, 1959 = 4,170 out of 9,670 cars, 1960 = 5,231 out of 10,261 cars, 1961 = 6,915 out of 10,939 cars, and 1962 = 14,232 out of 14,531 cars.
NUMBER CRUNCHING AND PRESS COMMENTARY
226 The May 1955 issue of Motor Trend set tongues wagging with this Rumor Mill column nugget: “The Chevrolet Corvette may drop fiberglass for 1956 production. The excellent quality of current Corvette bodies is achieved at too high a price (not passed on to consumers). Hand finishing of the plastic coupled with a high parts-rejection rate are the trouble-causers. Corvette is in the sports-car field to stay, so steel is the next big step.” Needless to say, it was not to be.
227 In the October 1956 issue of Hot Rod, writer Racer Brown evaluated an early-production 1957 Corvette equipped with the optional metallic brake linings and wrote, “You just stand on ’em and they bring the car down to smooth, straight-line, nonskid stops from high speeds. We tried this with our test car more than 20 times in a row without any appreciable fade.”
228 Despite a few cooling-off periods where General Motors voluntarily chose not to publicize Corvette’s winning ways on racetracks across the globe, the very first magazine ad that blatantly depicted a Corvette in sanctioned competition was the famed “Real McCoy” ad of mid-1956. Celebrating Corvette’s first-ever entry in world-class SCCA competition, the ad took aim at the Ford Thunderbird: “Other people make a luxury car that has much the same dimensions as this. That’s not so tough. And the Europeans make some real rugged competition sports cars, and that’s considerably tougher. But nobody but Chevrolet makes a luxury car that’s also a genuine 100-proof sports car. It’s a wicked combination to work out, and we didn’t hit it overnight.” The ad’s main image showed a stripped-down Vette with a grill-less gaping maw, auxiliary driving lights, and racing stripes that forever changed the way Corvette was seen and marketed.
There’s no doubt that the appearance of Ford’s 1955 Thunderbird halted plans to discontinue the Corvette despite a disastrous 1954 retail showing. That said, the only place for the T-Bird in the SCCA realm was in the spectator parking lot.
229 And about those cooling-off periods: the first arrived on June 6, 1957, in the form of the notorious AMA ban. Certain lawmakers and members of the insurance industry kept a close eye on Detroit’s horsepower war. They felt that the growing emphasis on power and speed encouraged reckless driving, especially among the growing pool of young drivers. So they pressured the Automobile Manufacturers’ Association (AMA), an industry lobbying group, to urge automakers to stop promoting performance. Sensing that the “voluntary” nature of the ban hid sharp teeth, Detroit fell in line. Immediate victims were factory-sponsored racing programs in NASCAR, USAC, and SCCA (that means you, Corvette). For its part, NASCAR immediately outlawed fuel injection and supercharging, killing Ford’s one-year affair with the belt-driven McCulloch supercharger and dulling GM’s interest in the Rochester fuel-injection program. Detroit still raced, but efforts had to be covert (under the guise of privateer race teams), and the full-steam-ahead development of high-performance machinery was sadly curtailed. By 1962, after five years of oppression, the youth market had exploded, and baby boomers demanded exciting, fast cars. Henry Ford was the first Detroit executive to declare a return to factory-sponsored racing, and the rest of the industry followed shortly.
230 Showcasing automobile-accident trends and statistics since 1931 (except during World War II), The Travelers Insurance Companies of Hartford, Connecticut, published an annual booklet titled Heedless Horsepower. The 1957 edition of this 30-page study appeared at the height of Detroit’s infatuation with advertised power ratings and just in time for Corvette’s historic shattering of the 1-hp-per-cubic-inch barrier with the Ram-Jet 283. Heedless Horsepower was packed with grim statistics citing the predictable linkage between youth, speed, powerful cars, and accidents.
231 Blending fear-mongering propaganda with tragic facts, the 1957 edition of Heedless Horsepower warned, “In the year 1956, [when] the Age of the Automobile came into its own, automobile manufacturers fashioned dreams of steel: powerful, sleek, multicolored models with push-button operation from dashboard to taillight. They killed, maimed, crippled, and destroyed more men, women, children, and property than ever before. We see the reckless young dashing to a date with eternity. State by state, day by day, we can call off the grisly roll: 40,000 deaths, almost 6 percent more than 1955.”
232 Interestingly, Heedless Horsepower didn’t single out any particular manufacturer. Rather, it used numbers to deliver its sobering, anti-performance message. Statistics comparing 1955 and 1956 included these items: 40,000 deaths, 2,200 more than 1955. In 1956 there were 2.368 million injuries, 210,000 more than 1955. And casualties from speeding totaled 812,750. Pedestrian casualties totaled 233,080, 2,680 more than 1955. Heedless Horsepower also studied when accidents happened and reported that 16,680 deaths occurred on weekends, almost 42 percent of the total. Youth was also at play, with 27.6 percent of the drivers involved in fatal accidents younger than 25 years of age. And in a thinly veiled poke at the vehicles involved in these accidents, the report said, “almost 80 percent of the accidents occurred on dry roads in clear weather,” that “more than 81 percent of the casualties resulted from driver error,” and that “more than 23 percent of the deaths and 28 percent of the injuries occurred between 4 and 8 pm.”
233 Less than a decade later, consumer advocate Ralph Nader’s Unsafe at Any Speed arrived in 1965. A non-fiction best seller, the book devoted a chapter to attacking the Corvair (Arkus-Duntov’s juggled tire-pressure fix was discussed) and opened the door to government oversight. Although painful, (at times) unfair, and biased, Unsafe at Any Speed did more good than harm. Carmakers eventually broke away from long-held beliefs that discussion of accidents hurt sales, and we can thank these publications and activists for the extremely safe nature of the modern automobile. It was certainly true that striking a tree at faster than 30 mph in any average American car built before January 1, 1968 (when federal laws mandated factory installation of seat belts in all new cars), was likely to result in serious injury. A similar impact today would most likely result in occupants walking away from the incident.
234 Between 1957 and 1962, a total of 7,828 Rochester mechanical-fuel-injection units were installed on Corvettes for retail sale to the general public. The resulting take rates are: 1957, 1,040 out of 6,339 cars; 1958, 1,511 out of 9,168 cars; 1959, 920 out of 9,670 cars; 1960, 859 out of 10,261 cars; 1961, 1,580 out of 10,939 cars; and 1962, 1,918 out of 14,531 cars (see Chapter 3 for 1963–1965 Sting Ray fuel-injection data). Rochester fuel injection was also offered on 1957–1959 full-sized passenger cars, with 1,530 sold in 1957 alone. Exact production records for 1958 and 1959 full-sized vehicle fuel-injection installations haven’t surfaced yet, but it is almost certain that output was lower than in 1957.
235 Remembering that Chevrolet envisioned fuel injection as being just as helpful to economy and drivability as it was to maximum performance, the Rochester unit was made available on the mild, lower-compression, hydraulic-cam-equipped 283 as well as the headline-stealing version with its elevated compression, solid lifters, and Duntov cam. Corvette sales brochures claimed the lower-output fuel-injection engine options “combined the best features of the proven Ramjet Fuel Injection with exceptional smoothness and reliability.” The downside was the fuel-injection unit cost a heady $484.20 regardless of which version of the 283 it was bolted to. This dual-identity strategy was also applied to 1957–1959 full-sized passenger cars where the fuel-injection mill also came in two levels of performance.
236 So how many Corvette fuel-injection buyers went for the milder 250-hp unit instead of the high-revving 290-hp unit? In 1957: 284 mild/756 wild, in 1958: 504 mild/1,007 wild, in 1959: 175 mild/745 wild, and in 1960: 100 mild/759 wild. For 1961, all fuel-injected engines were fitted with improved cylinder heads with bigger intake valves (1.94 instead of 1.72; exhaust valves remained at 1.50 inches) and ports (essentially cast-iron copies of the still-born 1960 aluminum-head option; see Fact 190). The improved 1961 heads bumped base fuel-injection power to 275 hp, while the top-dog fuel-injection engine climbed to 315 hp. Once again, the wild fuelie outsold its little brother, 118 mild/1,462 wild.
237 By 1962, Chevrolet faced the depressing reality that fuel injection was predominantly seen as a high-performance item. Mass-market appreciation and use of its greater benefits was still decades away. To give the buyer what he wanted while simultaneously simplifying inventory and streamlining production hassles, Chevrolet dropped the lukewarm fuelie option and based all 1962 fuel-injection engines on the new 327-ci V-8, with 360 hp and 352 ft-lbs of torque. Chevrolet built 1,918 units, keeping the price steady at $484.20.
238 “Since October 20, 1961, high-performance Corvette engines with option 396 (340 hp) or option 582 (360 hp) have been built with double gaskets on each cylinder head. With the two head gaskets, the compression ratio of these engines is reduced to 10.5:1. Corvette engines with these high-performance options built prior to the production change have single gaskets at each head and a compression ratio of 11.25:1. Corvette engines with 11.25:1 compression ratio require Super Premium fuel (100–102 Research Octane) or problems of detonation, pre-ignition, or die-seling may result.” These words appeared on a Chevrolet Technical Service Bulletin issued on January 2, 1962, and solved the head-scratching mystery encountered when early-build 1962 Corvette fuelie engine disassemblers encountered two head gaskets on each bank. It wasn’t a rumor or myth. Chevrolet also manipulated compression on certain 409 W-engines in this same time period by adding gaskets.
239 In December 1953, many Chevrolet engineers were probably preoccupied with holiday preparations. Not Arkus-Duntov. On December 13, he submitted an essay titled “Thoughts Pertaining to Youth, Hot Rodders, and Chevrolet” to his boss, Maurice Olley. In it, he wrote, “A young man buying a (Hot Rod, Hop Up, etc.) magazine for the first time immediately becomes introduced to Ford. It is reasonable to assume that when hot rodders or hot-rod-influenced persons buy transportation, they buy Fords. As they progress in age and income, they graduate from jalopies to second-hand Fords, then to new Fords.”
240 When Arkus-Duntov wrote his manifesto in the final weeks of 1953, Ford’s modern OHV Y-block V-8 was just entering the market as a 1954 offering. Was Arkus-Duntov aware of the imminent release of Chevrolet’s small-block V-8 when he wrote this document? Yes. In a four-part summary of Ford’s advantages, he wrote, “[The appearance of Ford overhead V-8 [is] now one year ahead of us.” This is a clear indicator that he was in on the 1955 model-year launch of the 265-ci Chevy small-block V-8. Virtually overnight, car magazines caught on to the 265’s inherent power advantage over Ford’s asthmatic Y-block, and the Ford dynasty crumbled soon after. It is ironic that today, many readers of the major hot-rod-type magazines moan that they’re “full of nothing but Chevys.” Before 1955, nobody could have foreseen this twist of fate.
241 Arkus-Duntov’s habit of writing memos directly to upper management occasionally stepped on the toes of his immediate bosses, but he succeeded in changing and focusing corporate thinking on many pivotal occasions. Another memo, dated October 15, 1954, was sent directly to Chevrolet division chief engineer Ed Cole. Bypassing the uncooperative Maurice Olley, it pled for a special team of engineers dedicated to nothing but Corvette advancement. Cole listened, and the note led to Arkus-Duntov’s post as Corvette’s (unofficial, until 1968) program manager, where one of his early assignments was adapting the 265 V-8 to the Corvette for its 1955 rollout.
