Saturday, September 9, 2023

Corvette

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.

Naval Battle between the French corvette La Bayonnaise and the British frigate HMS L'Embuscade, 14 December 1798, by Jean Francois Hue (1751-1823).

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.

HMCS Bowmanville (K 493), Royal Canadian Navy Corvette of WWII.

Because of the nature of sea battles prior to the Second World War, ships the size of the corvette tended to be neglected, the interest in smaller warships be centred on the ever smaller torpedo boats and the two work-horses of the fleets, the frigate and the destroyer, both of which were better suited to support cruisers patrolling the trade routes of the empire and the battleships of the high-seas fleets.  What saw a revival of interest was the war-time need to protect the trans-Atlantic and Arctic Sea convoys.  While the small corvettes, marginal in blue-water conditions, weren’t ideal for the role, they could be produced quickly and cheaply and, as a war-time necessity, were pressed into service as a stop-gap until more destroyers became available.  An additional factor was their small size which meant they could be built in many of the small, civilian shipyards which would have lacked the capacity to construct a frigate, let alone a destroyer.  Since the war, the corvette as a designation has essentially become extinct but there have long been frigates and fast patrol boats in service with many navies which correspond in size with the traditional Second World War corvette.


The early Chevrolet Corvettes, C1, C2 & C3 

1953 Corvette.

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.

1953 Corvette.

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.

1954 Corvette.

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).

1955 Corvette V8.

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.

1956 Corvette.

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.

1957 Corvette (fuel injected).

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, 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 which were offered only in heavyweight machines which, although fast, were no sports cars, heavy cruisers rather than corvettes.

1958 Corvette.

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.

1962 Corvette.

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.

1963 Corvette.

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.

1965 Corvette 396.

In what was an overdue upgrade, Chevrolet made four-wheel disc brakes standard for the 1965 model year although the drums remained available for anyone who wished to save a few dollars.  Those who opted to eschew the dramatic improvement in braking offered were probably specialists; because of internal friction the discs did impose a (very slight) performance and economy reduction which was why drums were long preferred on the NASCAR ovals where brakes are rarely applied; few Corvette buyers chose to save the US$64.50 and the discs were definitely a good idea if the newest engine was chosen.  Mid-year, the big-block 396 cubic-inch (6.5 litre) V-8 became available and it was rated at 425 hp, a figure few doubted after seeing the performance figures.  On paper, the 396 seemed a convincing bargain because, at under US$300, it offered another 50 hp over the fuel-injected 327 which cost over US$500.  There were charms only the fuel-injected unit could provide but the sales numbers were clear about what buyers preferred, the 396 out-selling it by three to one and before the year was out, the Rochester option was retired and it wouldn’t be until 1982, in the age of the micro-chip, that Chevrolet would again offer a fuel-injected Corvette.  Buyers clearly were convinced by the big-block idea but the sections of the motoring press were ambivalent, Car & Driver's (C&D) review suggesting that while "...there are many sports cars which really need more power, the Corvette isn’t one of them."  Unlike the chauvinistic English motoring press which tended to be a bit one-eyed about things like Jaguars and Aston-Martins, there were many in the US motoring media who really didn’t approve of American cars and wished they were more like Lancias.  People should be careful what they wish for.

Same L72 engine, different labels: An early one (left) with a 450 HP sticker and a later build (right) with a 425 HP label.  

Most fetishized by the Corvette collector community are (1) rare models, (2) rare options singularly or in combinations and (3) production line quirks, especially if accompanied by documents confirming it was done by the factory.  There were a few of all of these during the Corvette’s first two decades and some of them attract a premium which is why the things can sell for over US$3 million at auction.  Other quirks bring less but are still prized, including the handful of 1966 cars rated at 450 hp.  The L72 version of the 427 cubic inch engine was initially listed as developing 450hp @ 5800 rpm, something GM presumably felt compelled to do because the 396 had been sold with a 425 hp rating and the first few cars built included an air-cleaner sticker reflecting the higher output.  However, the L72 was quickly (apparently for all built after October 1965) re-rated at 425 hp @ 5600 rpm although the only physical change was to the sticker, the engines otherwise identical.  Chrysler used the same trick when advertising the 426 Street Hemi at 425 hp despite much more power being developed at higher engine speeds and that reflected a trend which began in the mid-1960s to under-rate the advertised output of the most powerful engines, a response to the concerns already being expressed by safety campaigners, insurance companies and some politicians.  Later Corvettes would be rated at 435 hp and it wasn’t until the 1970 model year that Chevrolet would list a 450 hp option (the 454 cubic inch (7.4 litre) LS6) but that was exclusive to the intermediate Chevelle and it remains the highest advertised rating of the muscle car era.  GM did plan that year to release a LS7 Corvette rated at 465 hp, building at least one prototype and even printing the brochures but the universe had shifted and the project was stillborn.  So, all else being equal, an early-build 1966 Corvette with a 450 HP sticker on the air-cleaner should attract a premium but Chevrolet kept no records of which cars got them and with the stickers available for under US$20, it's obvious some have been "backdated", thus the minimal after-market effect.  Nor is there any guarantee some later-build vehicles didn't receive the stickers at the factory so even the nominal October 1965 "cut-off" isn't regarded as iron-clad, many assembly lines at the time known to use up superseded parts just to clear the inventory.  Not easily replicated however was another rarity from 1966.  That year, only 66 buyers chose RPO N03, a 36 (US) gallon (136 litre) fuel tank.  Depending on the the engine/transmission combination and the final-drive ratio chosen, a Corvette's fuel economy was rated usually between "bad" and "worse" so the "big tank option" did usefully increase the range but it was really aimed at those using their cars in endurance racing.   

1967 Corvette L88.

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 twenty were sold in 1967, the survivors among the most sought-after Corvettes, one selling at auction in 2014 for US$3.85 million.

Joe Biden (b 1942; US president since 2021) in his 1967 Corvette.

Given he was already 62 when Mean Girls was released in 2004, most assumed it must have been an intern who provided the intelligence (1) that October 3 is "Mean Girls Day" and (2) "Get in loser, we're going shopping" is a line waiting to be modified and re-purposed.  Thus the tweet in 2022 although there was some subterfuge involved, the photograph actually from a session at his Wilmington, Delaware estate on July 16 2020.  The excuse for not taking a new snap probably was legitimate, the Secret Service most reluctant to let him behind the wheel.  The presidency is often called the most powerful office in the world but he's still not allowed to drive his own Corvette and George HW Bush (George XLI, 1924-2018; US president 1989-1993) encountered push-back when he refused to eat broccoli, apparently still scarred by the experience when young of having the green stuff forced on him by his mother.  He was far from the only head of state to have had unresolved issues with his mother.

President Biden's Corvette Sting Ray (it was two words in the C2 era) was ordered with the base version of the 327 rated at 300 hp, coupled to a four-speed manual gearbox.  For what most people did most of the time the combination of the base engine and the four-speed was ideal for street use although there were some who claimed the standard three-speed transmission was even more suited to the urban environment, the torque-spread of even the mildest of the V8s such that the driving experience didn't suffer and fewer gearchanges were required.  Those wanting the automatic option were restricted still to the old two-speed Powerguide, the newer Turbo-Hydramatic with an extra ratio simply too bulky to fit (many have subsequently modified and updated their early cars with a Turbo-Hydramatic but they didn't have to organize the production line upon which thousands would be built).  The 1967 cars were actually an accident of history, the C3 slated for release as 1967 models delayed (the issues said to be with with aerodynamics which in the those days meant spending time in the wind tunnel and on the test track, computer modelling of such things decades away) by one season.  Sales were thus down from 1966 as the new, swoopy body was much anticipated but the 1967 cars are now among the most coveted.     

1969 Corvette L88.

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.  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 in 1968-1969 was the L88 and in the two seasons it was offered in the C3, eighty were sold.

1969 Corvette ZL1 Roadster.

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.

1969 Corvette ZL1 Coupé.

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.

800 cfm (cubic feet per minute) carburetor on 1970 Corvette LT1.

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.  In the end, the highest powered 454 in the Corvette would be the LS5 and its output was down to 390 hp although the performance figures it delivered suggested it was perhaps a little healthier.  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 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 by which time it’s been detuned to 255 hp, the compensation being it could that year be ordered with air-conditioning although testers noted that when run to the redline, the cold air stopped flowing, the very reason Detroit in those years rarely offered the option with the most highly-tuned engines.

1980 Corvette 305.

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, things like seats and air-conditioning systems much improved.  A sort of nadir is noted for the 1980 models sold in Californian which, because of their 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 those of a few years earlier and if things had improved by 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.  Remarkably, the C3 remained in production until 1982, the last sold the following year.

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