Chevrolet Corvette C2 Sting Ray

(1962-1967)
Overview
Manufacturer	Chevrolet Division of General Motors
Also called	Chevrolet Corvette Sting Ray
Production	1962–1967
Model years	1963–1967
Assembly	St. Louis, Missouri, United States
Body and chassis
Class	Sports car
Body style	2-door convertible 2-door coupé
Layout	FR layout
Related	Duntov LightWeight Superformance Corvette Grand Sport
Powertrain
Engine	327 cu in (5.4 L) Small-Block V8 (1963–1965) 327 cu in (5.4 L) L75 Small-Block V8 327 cu in (5.4 L) L76 Small-Block V8 (1963–1965) 327 cu in (5.4 L) L79 Small-Block V8 (1965-1967) 327 cu in (5.4 L) L84 Small-Block FI V8 (1963–1965) 396 cu in (6.5 L) L78 Big-Block V8 (1965) 427 cu in (7.0 L) L36 Big-Block V8 (1966–1967) 427 cu in (7.0 L) L72 Big-Block V8 (1966–1967) 427 cu in (7.0 L) L68 Big-Block V8 (1967) 427 cu in (7.0 L) L71 Big-Block V8 (1967) 427 cu in (7.0 L) L89 Big-Block V8 (1967) 427 cu in (7.0 L) L88 Big-Block V8 (1967)
Transmission	3-speed manual 4-speed manual 2-speed Powerglide automatic
Dimensions
Wheelbase	98.0 in (2,489 mm) (MY1963)
Length	179.3 inches (4,554 mm)
Width	69.6 in (1,768 mm)
Height	49.8 in (1,265 mm) Coupe, convertible with hardtop 49.3 in (1,252 mm) Convertible with soft top

The Chevrolet Corvette (C2) (C2 for Second Generation), also known as the Corvette Sting Ray, is a sports car produced by the Chevrolet division of General Motors for the 1963 through 1967 model years.

History

The 1963 Sting Ray production car's lineage can be traced to two separate GM projects: the Q-Corvette, ­and perhaps more directly, Mitchell's racing Stingray. The Q-Corvette, initiated in 1957, envisioned a smaller, more advanced Corvette as a coupe-only model, boasting a rear transaxle, independent rear suspension, and four-wheel disc brakes, with the rear brakes mounted inboard. Exterior styling was purposeful, with peaked fenders, a long nose, and a short, bobbed tail.

Meanwhile, Zora Arkus-Duntov and other GM engineers had become fascinated with mid and rear-engine designs. It was during the Corvair's development that Duntov took the mid/rear-engine layout to its limits in the CERV I concept. The Chevrolet Experimental Research Vehicle was a lightweight, open-wheel single-seat racer. A rear-engined Corvette was briefly considered during 1958-60, progressing as far as a full-scale mock-up designed around the Corvair's entire rear-mounted power package, including its complicated air-cooled flat-six as an alternative to the Corvette's usual water-cooled V-8. By the fall of 1959, elements of the Q-Corvette and the Stingray Special racer would be incorporated into experimental project XP-720, which was the design program that led directly to the production 1963 Corvette Sting Ray. The XP-720 sought to deliver improved passenger accommodation, more luggage space, and superior ride and handling over previous Corvettes.

While Duntov was developing an innovative new chassis for the 1963 Corvette, designers were adapting and refining the basic look of the racing Stingray for the production model. A fully functional space buck (a wooden mock-up created to work out interior dimensions) was completed by early 1960, production coupe styling was locked up for the most part by April, and the interior, instrument panel included was in place by November. Only in the fall of 1960 did the designers turn their creative attention to a new version of the traditional Corvette convertible and, still later, its detachable hardtop. For the first time in the Corvette's history, wind tunnel testing helped refine the final shape, as did practical matters like interior space, windshield curvatures, and tooling limitations. Both body styles were extensively evaluated as production-ready 3/8-scale models at the Cal Tech wind tunnel.

The vehicle's inner structure received as much attention as the aerodynamics of its exterior . Fiberglass outer panels were retained, but the Sting Ray emerged with nearly twice as much steel support in its central structure as the 1958-62 Corvette. The resulting extra weight was balanced by a reduction in fiberglass thickness, so the finished product actually weighed a bit less than the old roadster. Passenger room was as good as before despite the tighter wheelbase, and the reinforcing steel girder made the cockpit both stronger and safer.

Design and engineering

The first-ever production Corvette coupe, a futuristic fastback, sported a for its time period unusual styling element - a divided rear window. The rear window's basic shape had been originally conceived by Bob McLean for the Q-model. The rest of the Sting Ray design was equally stunning. Quad headlamps were retained but newly hidden - the first American car so equipped since the 1942 DeSoto. The lamps were mounted in rotating sections that matched the sharp-edged front end with the "eyes" closed. The Corvette continued to use hidden headlamps until the C6 model debuted in 2005. Coupe doors were cut into the roof, which made entry/exit easier in such a low-slung closed car. Faux vents were located in the hood and on the coupe's rear pillars; functional ones had been intended but were cancelled due to cost considerations. The fastback design was later adopted by another GM car, the third-generation Buick Riviera that debuted in 1971, with the "Boattail" nickname applied to the larger Buick design.

The Sting Ray's interior carried a new interpretation of the twin-cowl Corvette dash motif used since 1958, It was also more practical, now incorporating a roomy glovebox, an improved heater, and the cowl-ventilation system. A full set of round gauges included a huge speedometer and tachometer. The control tower center console returned, somewhat slimmer but now containing the clock and a vertically situated radio. Luggage space was improved as well, though due to a lack of an external trunklid, cargo had to be loaded behind the seats. The spare tire was located at the rear in a drop-down fiberglass housing beneath the gas tank (which now held 20 gallons instead of 16). The big, round deck emblem was newly hinged to double as a fuel-filler flap, replacing the previous left-flank door.

Though not as obvious as the car's radical styling, the new chassis was just as important to the Sting Ray's success. Maneuverability was improved thanks to the faster "Ball-Race" steering and shorter wheelbase. The latter might ordinarily imply a choppier ride, but the altered weight distribution partly compensated for it. Less weight on the front wheels also meant easier steering, and with some 80 additional pounds on the rear wheels, the Sting Ray offered improved traction. Stopping power improved, too. Four-wheel cast-iron 11-inch drum brakes remained standard but were now wider, for an increase in effective braking area. Sintered-metallic linings, segmented for cooling, were again optional. So were finned aluminum drums, which not only provided faster heat dissipation (and thus better fade resistance) but less unsprung weight. Power assist was available with both brake packages. Evolutionary engineering changes included positive crankcase ventilation, a smaller flywheel, and an aluminum clutch housing. A more efficient alternator replaced the old-fashioned generator.

The independent rear suspension Duntov created for Sting Ray was essentially a frame-mounted differential with U-jointed half-shafts tied together by a transverse leaf spring - a design derived from the CERV I concept. Rubber-cushioned struts carried the differential, which reduced ride harshness while improving tire adhesion, especially on rougher roads. The transverse spring was bolted to the rear of the differential case. A control arm extended laterally and slightly forward from each side of the case to a hub carrier, with a trailing radius rod mounted behind it. The half-shafts functioned like upper control arms. The lower arms controlled vertical wheel motion, while the trailing rods took care of fore/aft wheel motion and transferred braking torque to the frame. Shock absorbers were conventional twin-tube units. Considerably lighter than the old solid axle, the new rear suspension array delivered a significant reduction in unsprung weight, which was important since the 1963 model would retain the previous generation's outboard rear brakes. The new model's front suspension would be much as before, with unequal-length upper and lower A-arms on coil springs concentric with the shocks, plus a standard anti-roll bar. Steering remained the conventional recirculating-ball steering design, but it was geared at a higher 19.6:1 overall ratio (previously 21.0:1). Bolted to the frame rail at one end and to the relay rod at the other was a new hydraulic steering damper (essentially a shock absorber), which helped soak up bumps before they reached the steering wheel. What's more, hydraulically assisted steering would be offered as optional equipment for the first time on a Corvette - except on cars with the two most powerful engines -and offer a faster 17.1:1 ratio, which reduced lock-to-lock turns from 3.4 to just 2.9.

Drivetrains were carried over from the previous generation, comprising four small block 327 V8s, three transmissions, and six axle ratios. Carbureted engines came in 250, 300, and 340-horsepower versions. As before, the base and optional units employed hydraulic lifters, a mild camshaft, forged-steel crankshaft, 10.5:1 compression, single-point distributor, and dual exhausts. The 300-bhp engine produced its extra power via a larger four-barrel carburetor (Carter AFB instead of the 250's Carter WCFB), plus larger intake valves and exhaust manifold. Again topping the performance chart was a 360-bhp fuel-injected V8, available for an extra $430.40. The car's standard transmission remained the familiar three-speed manual, though the preferred gearbox continued to be the Borg-Warner manual four-speed, delivered with wide-ratio gears when teamed with the base and 300-bhp engines, and close-ratio gearing with the top two powerplants. Standard axle ratio for the three-speed manual or Powerglide automatic was 3.36:1. The four-speed gearbox came with a 3.70:1 final drive, but 3.08:1, 3.55:1, 4.11:1, and 4.56:1 gearsets were available. The last was quite rare in production, however.

Corvette's designers and engineers - Ed Cole, Zora Arkus-Duntov, Bill Mitchell, and others knew that after 10 years in its basic form, albeit much improved, it was time to move on. By decade's end, the machinery would be put into motion to fashion a fitting successor to debut for the 1963 model year. After years of tinkering with the basic package, Bill Mitchell and his crew would finally break the mold of Harley Earl's original design once and for all. He would dub the Corvette’s second generation "Sting Ray" after the earlier race car of the same name (but now spelled out in separate words).

The C2 was designed by Larry Shinoda under the direction of GM chief stylist Bill Mitchell. Inspiration was drawn from several sources: the contemporary Jaguar E-Type, one of which Mitchell owned and enjoyed driving frequently; the radical Stingray Racer Mitchell designed in 1959 as Chevrolet no longer participated in factory racing; and a Mako shark Mitchell caught while deep-sea fishing. Zora Arkus-Duntov ("father of the Corvette") disliked the split rear window (which also raised safety concerns due to reduced visibility) and it was discontinued in 1964, as were the fake hood vents.

Model year changes

1963

The 1963 Corvette Sting Ray not only had a new design, but also newfound handling prowess. The Sting Ray was also a somewhat lighter Corvette, so acceleration improved despite unchanged horsepower. 21,513 units would be built for the 1963 model year, which was up 50 percent from the record-setting 1962 version. Production was divided almost evenly between the convertible and the new coupe - 10,919 and 10,594, respectively - and more than half the convertibles were ordered with the optional lift-off hardtop.

VARIATIONS AND OPTIONAL ACCESSORIES:
mechanical steering, 3.4 - 2.9 turns of steering wheel lock to lock
4-speed mechanical gear box, fully synchronized (1 2.54, II 1.89, III 1.51, IV 1, Rev 2.61)
axle ratios 3.70 : 1, 3.08 - 3.36 - 3.55 - 3.70 - 4.11 - 4.56 : 1 (limited slip final drive) 250 and 300 hp engines
Powerglide automatic gear box, hydraulic torque convertor and planetary gears with 2 ratios (I 1.76, II 1, Rev 1.76), max ratio of convertor at stall 2.10
brakes with sq in, 928.15 sq cm
engine max power 300 hp at 5000 rpm, max torque 360 1b ft, 49.7 kgm at 3200 rpm, compression ratio 10.5 : 1, hydraulic tappets
axle ratios 3.36 : 1 (automatic and 3-speed mechanical gear box), 3.36 - 3.08 : 1

Nevertheless, the coupe wouldn't sell as well again throughout the Sting Ray years. In fact, not until 1969 (by which time the coupe came with removable T-tops) did the closed Corvette sell better than the open one Equipment installations for 1963 began reflecting the market's demand for more civility in sporting cars. - the power brake option went into 15 percent of production, power steering into 12 percent. On the other hand, only 278 buyers specified the $421.80 air conditioning; leather upholstery - a mere $80.70 - was ordered on only about 400 cars. The beautiful cast aluminum knock-off wheels, manufactured for Chevy by Kelsey-Hayes, cost $322.80 a set, but few buyers checked off that option. However, almost 18,000 Sting Rays left St. Louis with the four-speed manual gearbox - better than four out of every five.

PERFORMANCE: 1963 (327 cu in)
max speed in 1st gear: 59 mph, 95 km/h
max speed in 2nd gear: 95 mph, 153 km/h
max speed in 3rd gear: 150.9 mph, 243 km/h
power-weight ratio: 8.8 lb/hp, 4.0 kg/hp
FUEL CONSUMPTION: 14.9 m imp gal, 12.4 m US gal, 19 1 x 100 km;
MAX SPEED: 150.9 mph, 243 km h

All 1963 cars had 327cid engines, which made 250 hp (186 kW) standard, with optional variants that made 300 hp (224 kW), 340 hp (254 kW) and 360 hp (268 kW). The most powerful engine was the Rochester fuel injected 327cid V8, which made 360 hp (272 kW). Options available on the C2 included AM-FM radio (mid 1963), air conditioning and leather upholstery. New for the 1963 model year was an optional electronic ignition, the breakerless magnetic pulse-triggered Delcotronic, first offered by Pontiac on some 1963 models.

1964 -Corvette Sting Ray Convertible

1964

For 1964 Chevrolet made only evolutionary changes to the Corvette. Besides the coupe's backbone window, the two simulated air intakes were eliminated from the hood, though their indentations remained. Also, the decorative air-exhaust vent on the coupe's rear pillar was made functional, but only on the left side. The car's rocker-panel trim lost some of its ribs and gained black paint between those ribs that remained; wheel covers were simplified; and the fuel filler/deck emblem gained concentric circles around its crossed-flags insignia. Inside, the original color-keyed steering wheel rim was now done in simulated walnut.

A few suspension refinements were made for 1964. The front coil springs were changed from constant-rate to progressive or variable-rate and were more tightly wound at the top, while leaf thickness of the rear transverse spring was also altered thus providing a more comfortable ride with no sacrifice in handling. Shock absorbers were reworked toward the same end. The 1964 Corvette arrived with a new standard shock containing within its fluid reservoir a small bag of Freon gas that absorbed heat. Chevy added more sound insulation and revised body and transmission mounts for the 1964 Corvette. It also fitted additional bushings to quiet the shift linkage and placed a new boot around the lever. The result was a more livable car for everyday transportation.

Drivetrain choices remained basically as before but the high-performance pair received several noteworthy improvements. The solid-lifter unit was massaged with a high-lift, long-duration camshaft to produce 365 bhp and breathed through a big four-barrel Holley carburetor instead of the base engine's Carter unit. The fuel injected engine also gained 15 horsepower, bringing its total to 375, but at a then-hefty $538.00. Although transmission options remained ostensibly the same for 1964, the two Borg-Warner T-10 four-speeds gave way to a similar pair of gearboxes built at GM's Muncie, Indiana, transmission facility. Originally a Chevy design, it had an aluminum case like the Borg-Warner box but came with stronger synchronizers and wider ratios for better durability and drivability. If enthusiast publications liked the first Sting Ray, they loved the 1964, though some writers noted the convertible's tendency to rattle and shake on rough roads. Sales of the 1964 Sting Ray reached 22,229 - another new Corvette record, if up only a little from banner-year 1963. Coupe volume dropped to 8304 units, but convertible sales more than compensated, rising to 13,925.

1965

For its third season, the 1965 Corvette Sting Ray further cleaned up style-wise and was muscled up with the addition of an all-new braking system and larger powerplants. 1965 styling alterations were subtle, confined to a smoothed-out hood now devoid of scoop indentations, a trio of working vertical exhaust vents in the front fenders that replaced the previous nonfunctional horizontal "speedlines," restyled wheel covers and rocker-panel moldings, and minor interior trim revisions. The 1965 Corvette Sting Ray became ferocious with the mid-year debut of a big-block V-8, the 425 hp (317 kW) 396 in³ (6.5 L) ("big block") V8. Ultimately, this spelled the end for the Rochester fuel injection system, as the carbureted 396/425 hp option cost $292.70 to the fuel injected 327/375 hp's $538.00. Few buyers could justify $245 more for 50 hp (37 kW) less, even if the FI cars offered optional bigger brakes not available on carburated models. After only 771 fuel injected cars were built in 1965, Chevrolet discontinued the option. It would be 18 years until it returned.

Four-wheel disc brakes were also introduced in 1965. The brakes had a four-piston design with two-piece calipers and cooling fins for the rotors. Pads were in constant contact with the rotors, but the resulting drag was negligible and didn't affect fuel economy. Further, the light touching kept the rotors clean and didn't diminish pad life, which was, in fact, quite high: a projected 57,000 miles for the front brakes and about twice that distance for the rear binders. Total swept area for the new system was 461 square inches, a notable advance on the 328 square inches of the previous all-drum system. Per pending federal regulation, there was also a dual master cylinder with separate fluid reservoirs for the front and rear lines. Road testers rightly applauded the all-disc brakes. Testers found that repeated stops from 100 mph produced no deterioration in braking efficiency, and even the most sudden stops were rock-stable. The drum brakes remained available, however, as a $64.50 credit option, but only 316 of the 23,562 Corvettes built that year came with drums. A side exhaust system appeared as an option as did a telescopic steering wheel. Also available were alloy spinner rims, at US$322 a set.

1966 Chevrolet Corvette 427 Roadster  

1966

For the 1966 Corvette, the big-block V-8 came in two forms: 390 bhp on 10.25:1 compression, and 425 bhp via 11:1 compression, larger intake valves, a bigger Holley four-barrel carburetor on an aluminum manifold, mechanical lifters, and four- instead of two-hole main bearing caps. Though it had no more horsepower than the previous high-compression 396, the 427 in³ (7 L), 430 hp (321 kW V8 packed a lot more torque - 460 pound/feet vs. 415. Of course, engine outputs were sometimes deliberately understated in the Sixties. Here, 420 and 450 bhp would be closer to the truth. Of course, all power ratings in the Sixties were also done in SAE Gross Horsepower, which is measured based on an engine without accessories or air filter or restrictive stock exhaust manifold, invariably giving a significantly higher rating than the engine actually produces when installed in the automobile. SAE Net Horsepower is measured with all accessories, air filters and factory exhaust system in place; this is the standard that all US automobile engines have been rated at since 1972. With big-block V-8s being the order of the day, there was less demand for the 327, so small-block offerings were cut from five to two for 1966, and only the basic 300- and 350-bhp versions were retained. Both required premium fuel on compression ratios well over 10.0:1, and they didn't have the rocket-like thrust of the 427s, but their performance was impressive all the same. As before, both could be teamed with the Powerglide automatic, the standard three-speed manual, or either four-speed option.

The 1966 model's frontal appearance was mildly altered with an eggcrate grille insert to replace the previous horizontal bars, and the coupe lost its roof-mounted extractor vents, which had proven inefficient. Corvettes also received an emblem in the corner of the hood for 1966. Head rests were a new option. This relative lack of change reflected plans to bring out an all-new Corvette for 1967. It certainly did not reflect a fall-off in the car's popularity, however. In fact, 1966 would prove another record-busting year, with volume rising to 27,720 units, up some 4200 over 1965's sales.

1967

The 1967 Corvette Sting Ray was the last Corvette of the second generation, and five years of refinements made it the best of the line. Although it was meant to be a redesign year, its intended successor the C3 was found to have some undesirable aerodynamic traits. Duntov demanded more time in the wind tunnel to devise fixes before it went into production.

Changes were again modest: Five smaller front fender vents replaced the three larger ones, and flat-finish rockers sans ribbing conferred a lower, less chunky appearance. New was a single backup light, mounted above the license plate. The previous models' wheel covers gave way to slotted six-inch Rally wheels with chrome beauty rings and lug nuts concealed behind chrome caps. Interior alterations were modest and included revised upholstery, and the handbrake moved from beneath the dash to between the seats. The convertible's optional hardtop was offered with a black vinyl cover, which was a fad among all cars at the time. The 427 was available with a 1282 ft³/min (605 L/s) Holley triple two-barrel carburetor arrangement, which the factory called Tri-Power. The ultimate Corvette engine for 1967 was coded L88, even wilder than the L89, and was as close to a pure racing engine as Chevy had ever offered in regular production. Besides the lightweight heads and bigger ports, it came with an even hotter camshaft, stratospheric 12.5:1 compression, an aluminum radiator, small-diameter flywheel, and a single huge Holley four-barrel carburetor. Although the factory advertised L88 rating was 430 bhp at 4600 rpm, the true rating was said to be about 560 bhp at 6400 rpm. The very high compression ratio required 103-octane racing fuel, which was available only at select service stations. Clearly this was not an engine for the casual motorist. When the L88 was ordered, Chevy made several individual options mandatory, including Positraction, the transistorized ignition, heavy-duty suspension, and power brakes, as well as RPO C48, which deleted the normal radio and heater to cut down on weight and discourage the car's use on the street. As costly as it was powerful - at an additional $1,500 over the base $4,240.75 price - the L88 engine and required options were sold to a mere 20 buyers that year. With potential buyers anticipating the car's overdue redesign, sales for the Sting Ray's final year totaled 22,940, down over 5,000 units from 1966 results. Meanwhile, Chevrolet readied its third-generation Corvette for the 1968 model year.

Reviews

The Sting Ray was lauded in the automotive press almost unanimously for its handling, road adhesion, and sheer power.

Car Life magazine bestowed its annual Award for Engineering Excellence on the 1963 Sting Ray. Chevy's small-block V-8 - the most consistent component of past Corvette performance was rated by the buff books to be even better in the Sting Ray. The 1963 was noted to have an edge over past models in both traction and handling because the new independent rear suspension reduced wheel spin compared to the live-axle cars.

Motor Trend tested a four-speed fuel injected version with 3.70:1 axle. They reported a 0-60 mph in 5.8 seconds and a 14.5-second standing quarter-mile at 102 mph. The magazine also recorded better than 18 miles per gallon at legal highway speeds and 14.1 mpg overall.

Motor Trend timed a 1964 fuel-injected four-speed coupe with the 4.11:1 rear axle, aluminum knock-off wheels (perfected at last and available from the factory), the sintered-metallic brakes, and Positraction through the quarter-mile in 14.2 seconds at 100 mph and the 0 to 60 mph in 5.6 seconds.

Road & Track tested the 300-bhp Powerglide automatic setup in a '64 coupe and recorded a 0-60-mph time of 8.0 seconds, a quarter-mile in 15.2 seconds at 85 mph, and average fuel consumption of 14.8 mpg.

Chevrolet Corvette C2 Sting Ray in Wheeler Dealers Series 10