Corvette (pronounced kawr-vet)
(1) In
historic admiralty use, a flush-decked warship of the seventeenth &
eighteenth centuries having a single tier of guns and one size down from a frigate;
in the US Navy called a sloop of war (usually truncated to sloop).
(2) In
current Admiralty use, a lightly armed and armored blue-water warship, one size
down from a frigate and capable of transoceanic duty.
(3) A
glass-fibre sports car produced in the US since 1953 by General Motors’ (GM) Chevrolet division.
1630–1640:
From the French, from the Middle French corvette (a small, fast frigate), from
either the Middle Dutch korver & corver (pursuit boat), the construct being
corf (fishing boat; literally “basket”) + -ette or the Middle Low German korf (small
boat; literally “basket”). The source of
both was the Latin corbis (basket) and, despite there existing also in Latin
the corbita (navis) (slow-sailing ship of burden, grain ship), again from
corbis, the relationship between this word and the later European forms is disputed. The suffix –ette is from the Middle English -ette, a borrowing from the Old French -ette, from the Latin -itta, the feminine form of -ittus.
It was used to form nouns meaning a smaller form of something. The Italian corvette & the Spanish
corbeta are French loan-words, the German equivalent being korvette. The obsolete alternative spelling was corvet.
Historically,
the term corvette, as applied to warships by various navies, can be misleading,
the vessels varying greatly in size, displacement, armament and suitability for
use on the high seas. As a general
principle, a corvette was understood to be a warship larger than a sloop, smaller
than a frigate and with fewer and sometimes smaller-bore guns than the latter,
always arrayed on a single deck.
Envisaged originally as a blue-water ship, they were allocated mostly to
costal duties or the range of activities smaller vessels fulfilled in fleet
support. In the manner of military
mission creep, overlap emerged and in some navies there were occasions when
newer corvettes were at least a large an well-gunned as some frigates although
the Royal Navy tended to maintain the distinctions, finding the smaller ships a
useful addition in the seventeenth century, their fast build rate affording the
Admiralty the means quickly to augment the firepower of a fleet. To the British however, they remained sloops
and it wasn’t until the 1830s the first vessels designated corvettes left UK
shipyards. It seems to have been the
French Navy which first described the “big sloops” as corvettes but, whether by
strategic design or in an attempt to confound the espionage activities of
opponents, by the late eighteenth century, French naval architects were
producing corvettes the British would have defined as frigates.
By 1952 the success in the US of MG and Jaguar had made it clear to
Chevrolet that demand existed for sports cars and the market spread across a
wide price band so with the then novel fibreglass offering the possibility of producing
relatively low volumes of cars with complex curves without the need for expensive
tooling or a workforce of craftsmen to shape them, a prototype was prepared for
display at General Motors’ 1953 Motorama show.
Despite the perception among some it was the positive response of the Motorama
audience which convinced GM’s management to approve production, the project had
already be signed-off but the enthusiastic reaction certainly encouraged
Chevrolet to bring the Corvette to market as soon as possible. The name Corvette was chosen in the hope of establishing a connection with the light, nimble naval vessels.
The haste brought its own, unique challenges. In 1953, Chevrolet had no experience of
large-scale production of fibreglass bodied cars but neither did anybody else,
GM really was being innovative. The
decision was thus taken to build a batch of three-hundred identical copies, the
rationale being the workers would be able to perfect the assembly techniques
involved in bolting and gluing together the forty-six fibreglass pieces produced
by an outside contractor. Thus,
essentially by a process of trial and error were assembled three hundred white
Corvettes with red interiors, a modest beginning but the sales performance was
less impressive still, fewer than two-hundred finding buyers, mainly because the
rate of production was erratic and with so few cars available for the whole
country, dealers weren’t encouraged to take orders; uncertainty surrounded the programme
for the whole year. Seldom has GM made
so little attempt actually to sell a car, preferring to use the available stock
for travelling display purposes, tantalizing those who wanted one so they would
be ready to spend when mass-production started.
The first Corvettes had been produced on a small assembly line in
Flint, Michigan to allow processes closely to be observed and optimized and by late
1953, Chevrolet was ready for high-volume runs, moving production to a plant in
Saint Louis, Missouri with the capacity to make ten-thousand a year. In anticipation of the Corvette being a
regular-production model, three additional colors (black, red, and blue) were
offered and the black soft-top was replaced by one finished in tan. However, despite the enhancements, demand
proved sluggish and fewer than four-thousand were sold in 1954 and there were
reasons. In 1961, Jaguar would stun the
world with its new sports car, powered by a triple-carburetor 3.8 litre straight-six
but in 1953, although Chevrolet’s Corvette boasted the same specification and a
much admired body, it wasn’t quite the sensation the E-type would be at
Geneva. The 1954 Corvette had gained a revised
camshaft which increased power by five horse-power, the output respectable by
the standards of the time but the only transmission available was the
Powerglide, a two speed automatic which for robustness and reliability matched
the Blue Flame six-cylinder engine (an updated version of the pre-war "Stovebolt") to which it was attached but neither
exhibited the dynamic qualities which had come to be expected from a sports car
although owners would have to get used to it: the Powerglide would be the only
automatic transmission offered in a Corvette until 1968. In truth, the Corvette was betwixt &
between; not quite a sports car yet lacking the creature comforts to appeal to
those wanting a relaxed GT (grand-tourer).
Chevrolet solved the problem of the Corvette’s performance deficit in
1955 by slotting in the new 265 cubic inch (4.3-litre) V-8 which would later
come to be called the small-block and become a corporate stable, appearing in
various forms in just about every Chevrolet and some models in other divisions
in the decades which would follow. Rated
now at a 195 horse-power which felt more convincing than the previous year’s 155,
it was offered also with a three-speed manual transmission and could now run
with the Jaguars, Mercedes-Benz and Ferraris on both road and track. The Corvette had become a sports car.
The V8 option had been introduced late in 1955 but the response of
buyers had convinced Chevrolet where the future lay; once available, only seven had chosen the old Blue Flame six so for 1956 the Corvette became exclusively V8-powered,
a specification by 2024 still not deviated from. To emphasize the new direction, the
Powerglide became optional and revisions to the engine meant power was now 210
horsepower (hp) although for those who wanted more, a dual four-barrel carburetor
setup could be specified which raised that to 225. Still made from fibreglass, the revised styling hinted
at some influence from the Mercedes-Benz 300SL Gullwing but had practical
improvements as well, external door handles appearing and conventional side windows replaced the fiddly removable curtains, a civilizing addition some British
roadsters wouldn’t acquire until well into the next decade. There was also the indication Chevrolet did
envisage a dual role for the car for in addition to the Powerglide remaining
available, buyers could now specify a power-operated soft top: whether it was sports car or GT was now up to the customer.
Chevrolet's experience in finding the six-cylinder Corvette had limited appeal once their V8 became available was in 1971 reprised across the Atlantic when Jaguar released the Series 3 E-Type (sometimes known in the US as XKE). The Jaguar V12 project had a long gestation and by the time eventually it entered production, the 420G (1961-1970 and known originally as the Mark X) which had been intended as its first recipient, had been retired. The task of engineering the much smaller XJ (introduced in 1968) to house the V12 was absorbing much energy so it was the E-Type in which the new engine was first used. Jaguar made the effort to prepare the new S3 E-Type to use both the long-running, 4.2 litre (258 cubic inch) XK straight-six and the 5.3 litre (326 cubic inch) V12, including printing promotional material, even glossy, full-color, multi-lingual brochures.
However, before series production began, the decision was taken to offer the S3 only with the V12 and although there are tales of six XK-engined prototypes having been built, the Jaguar-Daimler Historic Trust insists the true number was four (2 roadsters & 2 coupés with one right hand drive (RHD) and one left hand driver version of each); the LHD coupé with a manual transmission survived although when offered at auction in England, its rarity (genuinely it is unique) didn't attract a premium as it sold for a price little different from what might be expected for a V12 in the same condition. By 1974, when the effects of the spike in the price of oil began to affect demand for engines as thirsty as the V12, the E-Type was in its last days so the company made no attempt to resurrect one with the smaller engine, unlike Mercedes-Benz which quickly made available in the R107 roadster and C107 coupé the 2.7 litre (168 cubic inch) six as an alternative to the 3.5 (214 cubic inch) & 4.5 (276 cubic inch) V8s. Although it couldn't at the time have been predicted, the C107 in both six & eight cylinder form remained available until 1989 so the efforts taken during the first oil shock proved worthwhile. It wouldn't be until 1983 Jaguar offered the XJS (1975-1996 and (sort of) the E-Type's replacement) with a six-cylinder engine and, remarkably, the XJS would enjoy a longer life even than the R107, the last not leaving the factory until 1996.
In 1957, things started to get really serious, a four-speed manual
transmission was added, the V8 was bored out to 283 cubic inches (4.6 liters) which
increased power and, in an exotic touch which matched the Mercedes-Benz 300 SL (W198; 1954-1963),
Rochester mechanical fuel-injection was an (expensive) option, allowing the Corvette
to boast an engine with one hp per cubic inch, something in the past
achieved only by the big dual-quad Chrysler Hemis, offered only in heavyweight
machines which, although fast, were no sports cars, heavy cruisers rather than corvettes.
A noted change for 1958 was the tachometer moving from the centre of
the dashboard to a place directly in from to the driver, probably a wise move
given the propensity of the fuel-injected engine to high-speeds and output
continued to rise, by 1960 315 hp would be generated by the top
option. One big styling trend in 1957
had been the quad headlamps allowed after lighting regulations were relaxed
and these were added, unhappily according to some, to the Corvette for
1958. However, even many of those of those who admired the four-eyed look thought the lashings of chrome a bit much. Chrome was quite a thing in Detroit by 1958
and DeSotos, Lincolns, Buicks and such were displaying their shiny splendour but
it probably didn’t suit the Corvette quite so well which was unfortunate given it was adorned with much, even the headlight bezels getting a coating. A change of management at the top of Chevrolet's styling department ensured 1958 was peak-chrome for the sports car; cars from other divisions would for some time continue to drip the stuff but the Corvette would be notably more restrained.
Although the changes since 1963 had been many, the Corvette was still in its first generation but the 1962 model would be the end of the line. The front end had earlier been revised from its chromed origin and in 1961 a redesigned rear was added which saw the debut of the quad-taillight design which would for decades remain a distinctive feature. 1962 saw the introduction of a 327 cubic-inch (5.3 litre) V8, the fuel-injected version now up to 360 hp and one aborted project was the Grand Sport (GS) Corvette, a competition oriented model. It had been intended to build a hundred and twenty-five in order to homologate it in certain racing categories but GM, still (unlike its competitors) taking seriously the need to make it appear it was maintaining the industry's agreed ban on participation in motorsport, cancelled the programme after five had been built; all survived and are now expensive collectibles.
For 1963, unusually, the big news wasn’t what was under the hood (bonnet). The 327 V8 was carried over from 1962 but, other than the drive-train, it was a new car (later referred to as the C2, the 1953-1952 models now retrospectively dubbed the C1), offered for the first time as a coupé as well as the traditional convertible and with a revised frame which included independent rear suspension, a rarity at the time on US-built vehicles. One quirk of the 1963 coupés was the split-window design of the rear glass. A source of debate within Chevrolet, the anti-split faction eventually won and a single piece of glass was substituted in 1964 which of course rendered the 1963 cars instantly dated. As a result, a small-scale industry sprung up offering owners the chance to update their look to that of the 1964's single piece of glass and many cars were converted. That changed decades later when the unique feature of the 1963 car made it a much prized collectable and another small-scale industry briefly flourished converting them back and, whether true or urban myth, it’s said as many as 4% of the split-window coupés which now exist may be later models with a bit of judicious back-dating. Chevrolet officially had no involvement in racing but understood the Corvette’s appeal to those who did and in 1963 offered Regular Production Option (RPO) Z06 which included an improved brake and suspension package. Available only in conjunction with the 360 hp engine and a four-speed manual transmission, around two-hundred were built, most of them coupés.
Maybe even Chevrolet had moments of doubt after reading their copy of C&D and thought the 396
Corvette might have been a bit much because after providing cars for the press to
test, they issued a statement saying the 396 wouldn’t be available in the
Corvette after all but would be offered in the intermediate Chevelle as well as
the full-sized cars. The moment however quickly
passed, the 396 Corvette remaining on the books and by 1966 Chevrolet certainly agreed there was no substitute for cubic inches, the 396 replaced by a 427
cubic-inch (7.0 litre) iteration of the big-block. For 1966 it was still rated at 425 hp
but in 1967, a triple carburetor option sat atop the top engine, gaining an additional ten hp. There was however another,
barely advertised and rarely discussed because of its unsuitability for street
use and this was the L88, conservatively rated at 430 hp but actually
developing between 540-560. Essentially
a road-going version of the 427 used in the (unlimited displacement FIA Group 7 sports-car) Can-Am race series, just 20 were sold in 1967, the survivors among the most sought-after Corvettes,
one selling at auction in 2014 for US$3.85 million.
By the 1960s it was common for hard-tops to be on the option list of a roadster (in the era there was even one company which briefly (and unsuccessfully) offered fibreglass versions for Detroit's full-size convertibles) but Chevrolet gave C2 Corvette buyers the choice to have both a hard-top & soft-top or just one of the two. Remarkably (and presumably in places where rain events were predictable), a number of buyers did take the hard-top only course and the configuration wasn't unique to Chevrolet, Mercedes-Benz in some years offering its "Pagoda" roadster (W113; 1963-1971) with only a hard-top although it was listed a separate model: the "California Coupé" which, despite the name, was still a convertible and one which offered the additional practicality of a folding bench seat in the rear compartment, permitting (cramped) seating for two.
Joe Biden (b 1942; US president 2021-2025) in his 1967 Corvette.
Same L72 engine, different stickers: An early one (left) with a 450 HP sticker and a later build (right) with a 425 HP label.
The C2 Corvette had a short life of only five years and it would have been shorter still had not there been delays in the development of the C3 which went on sale in late 1967. Dramatically styled, the C3 eventually debuted for the 1968 model year, the lines reminiscent of the Mako Shark II (1965) concept car and the coupé included the novelty of removable roof panels. Underneath the swoopy body, the C3 was essentially the same as the C2 except the old two-speed Powerglide was retired, the automatic option now whichever of the three-speed Turbo-Hydramatics suited the chosen engine. The C3 also saw one of the early appearances of fibre-optic cables, used to provide an internal display so drivers could check the functionally of external lights and for 1969, the 327 was stroked to 350 cubic inches (5.7 litres), one of the surprisingly large number of changes which can make the 1968 Corvette something of a challenge for restorers, there being so many parts unique to that model-year. Still available was the L88 and in the two seasons it was offered in the C3, 196 were sold (80 in 1968 and 116 in 1969) but even in its most successful year, the option represented only .0030% of annual production.
However, there was one even more expensive option, the RPO ZL1, sometimes described as “an all aluminium L88” but actually with a number of differences some necessitated by the different metal while others were examples of normal product development. Again the fruit of Chevrolet’s support for the Can-Am teams, the ZL1 was no more suited to street use than the L88 and at US$4,718.35 was three times as expensive. In 1969, a basic Corvette listed at US$4,781 and if the ZL1 option box was ticked the price essentially doubled although beyond that temptations were few, like the L88, air conditioning, power steering, power brakes and even a radio not available. It was thus unsurprising demand was muted and it's now accepted that of the seven built, only two were sold, the other five being for engineering and promotional purposes, these “factory mules” scrapped or re-purposed after their usefulness was over. The yellow coupé last changed hands in October 1991 when it was sold in a government auction for US$300,000 (then a lot of money) after being seized by the DEA (Drug Enforcement Agency) and in January 2023, at auction, the orange roadster realized US$3.14 million. The yellow one sits now in the museum attached to Roger Judski's Corvette Centre in that hive of DEA activity: Florida.
So the orthodox wisdom is there are two “real” ZL1s and an unknown number of faux versions (described variously as clones, replicas, tributes etc, none of these terms having an agreed definition and thus not useful as indications of the degree to which they emulate a factory original). However, the “ultra” faction in the Corvette community maintains the yellow coupé is a genuine one-off and claim the orange roadster left the factory with an L88 engine and in that form it was raced, as well as when fitted with a ZL1. The faction further notes the orange machine is an early-build vehicle reported to have closed chamber heads whereas the RPO ZL1s used open chambers. The “moderate” faction continues to regard the count as two although nobody seems now to support the rumors which circulated for a few years indicating a third and even a fourth, the supposed “black roadster” later confirmed to be faux. Given all that, the fact the orange car sold for over US$3 million in 2023 does suggest that were the yellow one to go on the block, a new record price would be likely. Roger Judski (B 1947), owner of the yellow ZL1, has been trading Corvettes since 1965 and is as authoritative an expert on the breed as anyone and he belongs to the moderate faction which supports the orthodox count of two factory ZL1s.
The 1969 ZL1 and L88 however would prove to be peak C3 Corvette. Times were changing and in 1970 it was the Chevelle which was offered with Chevrolet’s top big-block street engine, the now 454 cubic-inch (7.4 litre) LS6 rated at 450 hp, the industry’s highest (official) rating of the era; plans for a 465 hp LS7 Corvette were cancelled as insurance costs and the regulatory environment began to tighten around the high-powered monsters although serious horsepower remained available: while the LS5 454 was rated at 390 horsepower, the performance it delivered suggested it was perhaps a little healthier. The Corvette highlight of the 1970s however came in 1971 with the availability of the RPO ZR2 for the LS6 engine, described in dealer sheets as the “RPO ZR2 Special Purpose LS6 Engine Package” and it can be regarded as a successor the L88, supplied with the Muncie M22 close-ratio (Rock-Crusher) four-speed manual transmission, transistorized ignition, a heavy-duty aluminum radiator (with shroud delete, a hint it really didn’t belong on the street), heavy-duty power disc brakes, F41 Special Suspension with specific springs, shocks and special front and rear sway bars. Like the L88s, air-conditioning and a radio were not on the option list, neither much used on race-tracks. Chevrolet built only a dozen ZR2 Corvettes (two of which were convertibles) in 1971, not because production deliberately was limited but because of the cost (the list price was a then substantial US$7.672.80) and their unsuitability for everyday use meant demand was subdued. Although scheduled for 1970, industrial relations problems delayed production of the ZR2 until 1971 by which time stricter regulations had compelled cancellation of the LS7 454 so RPO ZR2 was re-purposed for the LS6, rated at a conservative 425 horsepower although this didn’t fool the insurance industry.
Lurking behind the thunder of the 454 however was the most charismatic of the small-block Corvettes since the days of the fuel-injected 283 & 327. This was the 350 LT1, a high-revving mill very much in the tradition of the Camaro's 302 Z/28 (RPO Z28 picked up the slash when used as a model name) used in the (five litre (305 cubic inch) production car) Trans-Am series, which featured heavy-duty internals and high performance additions including solid valve lifters, forged pistons, an 11:1 compression ratio, four-bolt main bearing caps, a forged steel crank, a hi-lift camshaft, a baffled sump and a free-flowing induction and exhaust system. In a echo of the days of Rochester fuel-injection, it was almost twice the price of a 454 but was a persuasive package and over a thousand were made. Available only with a manual transmission, it lasted until 1972 and although the lowering of the compression ration meant power ratings dropped season-by-season (1970:370 HP; 1971:330 HP; 1972:255 HP), the 1972 number reflected the industry's change from quoting gross to nett horsepower so the reduction wasn't as dramatic as it might appear. Although still fast by most standards, the 1972 cars were somewhat less potent, the compensation being that by reducing the redline to 5600 RPM (to stop the belt flying off the compressor), the LT1 could that year be ordered with air-conditioning. Most desirable of the C3 LT1s were those ordered with the ZR1 package, fewer than 60 of which were delivered between 1970-1972. The ZR1 options were focused not on additional horsepower but rendering the chassis better suited for use in competition, the target market those who wanted to participate in the racing series run by the SCCA (Sports Car Club of America). Accordingly, what was included was a cold-air hood, a larger capacity cooling system (including a different shroud and fan optimized for high-speed operation), the famed Muncie M22 (rock crusher) four-speed manual transmission, electronic ignition, upgraded power brakes, stiffer shock-absorbers (dampers), springs and front & rear anti-roll (sway) bars. Given the emphasis, choosing the ZR1 package meant that, like the big-block L88s & ZL1, the fitting of luxuries like air conditioning, the rear-window defroster, power steering, the fancy wheel covers, alarm system and a radio were precluded. ZR1 buyers really did inhabit a niche market and the vehicles are now highly prized.
The LT1 is fondly remembered but from then on it was mostly downhill for the C3 although in its last decade its popularity reached new heights and in those years it was one of GM's most profitable lines. In 1975 both the convertible and the (by then much-detuned 454) big-block V8 were cancelled but tellingly, in that era of malaise, the C3 enjoyed a long India summer, its performance stellar on the sales charts if not the track and, with no appetite for horsepower, Chevrolet devoted attention to creature comforts, creature comforts like seats and air-conditioning systems much improved. A sort of nadir is noted for the 1980 models sold in Californian which, because of more stringent emission rules, were fitted only with an automatic transmission and the 305 cubic inch (5.0 litre) engine found often in station wagons and pick-up trucks although, it still managed to be a little brisker than the Blue Flame original. The Californian 305 was rated at 180 hp which was actually 15 more than the unfortunate 350 (L48) in the 1975 model which had been rated at the same 150 as the 1953 original (in 1975 the optional L82 engine was listed with 205 hp). The method of calculating the stated hp changed in 1972 so the earlier numbers are overstated compared with the newer but there's no doubt the Corvettes of the mid-1970s were making a lot less power than the earth-pawing fire-breathers of a few years earlier and if things had improved by the early 1980s, it wasn't by much. Both the tamest of the 1975 cars and the 1980 Californian 305 tend to be listed together among the least fondly remembered of the breed but enjoying solid demand to the end, the C3 remained in production until 1982, the last sold the following year.
No comments:
Post a Comment