Carburetor

Carburetor (pronounced kahr-buh-rey-ter or kahr-byuh-yey-tor)

(1) A device for mixing vaporized fuel with air to produce a combustible or explosive mixture for use in the cylinder(s) or chambers of an internal-combustion engine.

(2) In the slang of drug users, a water pipe or bong; a device for mixing air with burning cannabis or cocaine (rare since the 1970s and then usually in the form “carb” or “carby”).

1866: From the verb carburate, from the Italian carburate (to mix (air) with hydrocarbons”), an inflection of carburare & the feminine plural of carburato.  As a transitive verb carburet was used mean “to react with carbon”.  Strangely, the exact origin of the word is uncertain but it was likely a portmanteau of carbon (in the sensor of a clipping of hydrocarbon) + burette (a device for dispensing accurately measured quantities of liquid).  The construct was carb (a combined form of carbon) + -uret (an archaic suffix from Modern Latin) (uretum to parallel French words using ure).  The earlier compound carburet (compound of carbon and another substance; now displaced by carbide) was from 1795 and it was used as a verb (to combine with carbon) after 1802.  The use with reference to the fuel systems used in the internal combustion engines of vehicles dates from 1896.  Carburator, carbureter and carburetter were the now obsolete earlier forms and the standard spelling in the UK, Australia & New Zealand is carburettor.  Carb & carby (carbs & carbies the plural) are the the universally used informal terms (gasifer was rare) and although most sources note the shortened forms weren’t recorded until 1942 it’s assumed by most they’d long been in oral use.  Outside of a few (declining) circles, “carb” is probably now more generally recognized as the clipping of carbohydrate.  Carburetor & carburetion are nouns; the noun plural is carburetors.

One carburetor: 1931 Supercharged Duesenberg SJ with 1 x updraft Stromberg (left; the exhaust manifold the rare 8-into-1 monel "sewer-pipe") (left), 1966 Ford GT40 (Mark II, 427) with 1 x downdraft Holly (centre; the exhaust headers were referred to as the "bundle of snakes") and 1960 Austin Seven (later re-named Mini 850) with 1 x sidedraft SU.

Except for some niches in aviation, small engines (lawnmowers, garden equipment etc) and for machines where originality is required (historic competition and restorations), carburetors are now obsolete and have been replaced by fuel-injection.  There is the odd soul who misses the challenge of tinkering with a carburetor, especially those with the rare skill to hand-tune multiple systems like the six downdraft Webers found on some pre-modern Ferraris, but modern fuel injection systems are more precise, more reliable and unaffected by the G-forces which could lead to fuel starvation.  Fuel injection also made possible the tuning of induction systems to produce lower emissions and reduced fuel consumption, the latter something which also extended engine life because all the excess petrol which used to end up contaminating the lubrication system stayed instead in the fuel tank.

Two carburetors: 1970 Triumph Stag with 2 x sidedraft Strombergs (left), 1960 Chrysler 300F with 2 x Carter downdrafts on Sonoramic cross-ram (long) manifold (centre) and 1969 Ford Boss 429 with 2 x Holly downdrafts on hi-riser manifold.

Until the 1920s, all but a handful of specialized devices were simple, gravity-fed units and that was because the engines they supplied were a far cry from the high-speed, high compression things which would follow.  In the 1920s, influenced by improvements in military aviation pioneered during World War I (1914-1918), the first recognizably “modern” carburetors began to appear, the conjunction of adjustable jet metering and vacuum controls replacing the primitive air valves and pressurized fuel supply mechanisms allowed engineers to use a more efficient “downdraft” design, replacing the “updraft” principle necessitated by the use of the gravity-feed.  Between them, the “downdraft” and “sidedraft” (a favorite of European manufacturers) would constitute the bulk of carburetor production.  The next major advance was the “duplexing” of the carburetor’s internals, doubling the number of barrels (known now variously as chokes, throats or venturi).  Although such designs could (and sometimes were) implemented to double the capacity (analogous with the dual-core CPUs (central processing units) introduced in 2005), the greatest benefit was that they worked in conjunction with what was known as the “180^o intake manifold”, essentially a bifurcation of the internals which allowed each barrel to operate independently through the segregated passages, making the delivery more efficient to the most distant cylinders, something of real significance with straight-eight engines.  Few relatively simple advances have delivered such immediate and dramatic increases in performance: When the system was in 1934 applied to the them relatively new Ford V8 (the “Flathead”), power increased by over 25%.

Three carburetors: 1967 Jaguar E-Type (XKE) 4.2 with 3 x sidedraft SUs (left), 1967 Ferrari 275 GTB/C with 3 x downdraft Webers (centre) and 1965 Pontiac GTO with 3 x downdraft Rochesters.

Advances however meant the demand for more fuel continued and the first solution was the most obvious: new manifolds which could accommodate two or even three carburetors depending on the configuration of the engine.  Sometimes, the multiple devices would function always in unison and sometimes a secondary unit would cut-in only on demand as engine speed rose and more fuel was needed, an idea manufacturers would perfect during the 1960s.  World War II (1939-1945) of course saw enormous advances in just about every aspect of the design of internal combustion engines (ICE) and carburetors too were improved but in a sense, the concept had plateaued and it was fuel-injection to which most attention was directed, that being something which offered real advantages in flight given it was unaffected by G-forces, atmospheric pressure or acrobatics, working as well in inverted as level flight, something no carburetor could match.

Four carburetors: 1973 Jaguar XJ12 (S1) with 4 x sidedraft Zenith-Strombergs (left; the Jaguar V12 was unusual in that the carburetors sat outside the Vee), 1976 Aston Martin V8 with 4 x downdraft Webers (centre; Aston Martin-Lagonda originally fitted the V8 with fuel injection but it proved troublesome) and 1965 Ford GT40 (X1 Roadster 1, 289) with 4 x downdraft Webers (right, again with the "bundle of snakes" exhaust headers).

After the war, like the chip manufacturers with their multi-core CPUs in the early 2000s, the carburetor makers developed four-barrel devices.  In Europe, the preference for multiple single or two barrel (though they tended to call them “chokes”) induction but in the US, by the early-1950s just beginning the power race which would rage for almost two decades, for the Americans the four-barrel was ideal for their increasingly large V8s although sometimes even the largest available wasn’t enough and the most powerful engines demanded with two four-barrels and three two-barrels.  It was in the 1950s too that fuel-injection reached road cars, appearing first in a marvelously intricate mechanical guise on the 1954 Mercedes-Benz 300 SL (W198) Gullwing.  Others understood the advantages and developed their own fuel-injection systems, both mechanical and electronic but while both worked well, the early electronics were too fragile to be used in such a harsh environment and these attempts were quickly abandoned and not revisited until the revolution in integrated circuits (IC) later in the century.  Mechanical fuel-injection, while it worked well, was expensive and never suitable for the mass-market and even Mercedes-Benz reserved it for their more expensive models, most of the range relying on one or two carburetors.  In the US, Chevrolet persisted with mechanical fuel injection but availability dwindled until only the Corvette offered the option and in 1965 when it was made available with big-block engines which offered more power at half the cost, demand collapsed and the system was discontinued, the big engines fed either by three two barrels or one very large four barrel.

Other four barrel devices

Reggie (Reggie Bannister (b 1945) with Regman Quad-Barrel Dwarfcutter in Phantasm (1979).

 Four (and more) barrel weapons have long been common in fixed or mobile structures (warships, gun batteries etc) but are rare in anything hand-held because of the increases imposed in size & weight as well as the heat generated.  In fiction (notably video games and horror films) they’re a popular prop and the four barrel shotgun in Don Coscarelli’s cult classic Phantasm (1979) was among the more memorable.  An ad-hoc creation born of the need for more firepower (very much in the vein of the “…going to need a bigger boat” philosophy in the Film Jaws (1975), a line apparently improvised during filming because it appears neither in Peter Benchley’s (1940-2006) 1974 novel nor the original screenplay), it was made by welding together two double barrel shotguns and named the “Regman Quad-Barrel Dwarfcutter”.  It was that sort of film and freaks attracted to the design (which does seem hard to resist) have created Nerf-guns in the style.  Although rare, hand-carried, multi-barrel firearms have a history dating back centuries and provided the intended application is appropriate, they can be both effective and convenient, a number of manufacturers offering three and four barrel shotguns, all of which presumably include a section in the owner’s manual covering “recoil management”.  Very much in the spirit of those who took advantage of the modular construct of the early (and anyway already sometimes lethal) two-stroke Kawasaki triples (H1, H2, S1, S2 & S3; 1969-1975) to build a 48-cylinder version, nine-barrel(!) shotguns have been made... just in case.

Custom four barrel Vierling longarm by Johann Fanzoj (1790) of Ferlach, Austria.

The four-barrelled longarm was configured with a side-by-side double rifle (calibre: 9,3/9,3x74R), paired with an over-and-under shotgun (gauge 12/12/76).  Built to a customer specification to shoot four (plus two) times in sequence with “hot” barrels, the Vierling used H&H-type sidelocks with automatic ejectors.  An impressive example of the gunsmith's art, this was not a Phantasmesque welding job but an intricate design which had to regulate the rifle barrels two-times-two so they would shoot together to the same point of impact, in sequence.  First, the 9,3 barrels discharge, then by pushing the barrel selector forward, the shooter continues with the 12-gauge barrels with automatic ejection of the shotgun cartridges facilitating quick reloading… just in case.

English “Duck’s foot” four-barrelled pistol with walnut slab-sided butt and silver-wire scroll inlay, said to date from the early nineteenth century.  Note the angle of the barrels and thus the wide field of fire.

Collectors also prize bizarre and ambitious designs such as the four-barreled “duck’s foot” pistol.  Historians have questioned whether these weapons really were manufactured in the Georgian or Regency eras and some suggest they were a product of entrepreneurial Victorians creating “relics” which played into prejudices about just how bad were what were then the “olden days”.  The legend is these were early crowd-control devices with which some worthy (squire, mill or mine owner etc) could deter the mob (revolting peasants, disgruntled factory workers, whatever) which would have been inclined to take a chance against someone armed only with a single-shot pistol.  There’s nothing in the historic record to suggest riots and strikes were ever “controlled” with such things but the Victorians of the late nineteenth century were well aware they were the first generations to benefit from a standing, regulated constabulary so the need for such things would have seemed at least plausible.  The legend is they were also carried by naval captains in case of mutiny and while the Admiralty apparently never issued them, it’s not impossible some officers bought their own… just in case.

Five carburetors:  Le Monstre's 331 cubic inch (5.4 litre) Cadillac V8 (left) with its unusual (and possibly unique) five-carburetor induction system; the layout (one in each corner, one in the centre) is a "quincunx", from the Latin quīncunx.  Le Monstre ahead of Petit Pataud, Le Mans, 1950 (right).  At the fall of the checkered flag, the positions were reversed.  

Le Monstre was a much-modified 1950 Cadillac which ran at that year's Le Mans 24 hour endurance classic. one half of a two car team the other being a close to stock 1950 Cadillac coupe.  The idea behind the five carburettors was that by the use of progressive throttle-linkages, when ultimate performance wasn’t required the car would run on a single (central) carburettor, the other four summoned on demand and in endurance racing, improved fuel economy can be more valuable than additional power.  That’s essentially how most four-barrel carburettors worked, two venturi usually providing the feed with all four opened only at full throttle and Detroit would later refine the model by applying “méthode Le Monstre” to the triple carburettor systems many used between 1957-1971.  As far as is known, the only time a manufacturer flirted with the idea of a five carburetor engine was Rover which in the early 1960s was experimenting with a 2.5 (153 cubic inch) litre in-line five cylinder which was an enlargement of their 2.0 litre (122 cubic inch) four.  Fuel-injection was the obvious solution but the systems then were prohibitively expensive (for the market segment Rover was targeting) so the prototypes ended up with two carburettors feeding three cylinders and one the other two, an arrangement as difficult to keep in tune as it sounds.  Rover’s purchase of the aluminium 3.5 litre (214 cubic inch) V8 abandoned by General Motors (GM) meant the project was terminated and whatever the cylinder count, mass-produced fuel injection later made any configuration possible.  Motor racing is an unpredictable business and, despite all the effort lavished on Le Monstre, in the 1950 Le Mans 24 hour, it was the less ambitious Petit Pataud which did better, finishing a creditable tenth, the much modified roadster coming eleventh having lost many laps while being dug from the sand after an unfortunate excursion from the track.  Still, the results proved the power and reliability of Cadillac’s V8 and Europe took note: over the next quarter century a whole ecosystem would emerge, crafting high-priced trans-Atlantic hybrids which combined elegant European coachwork with cheap, powerful, reliable US V8s, the lucrative fun lasting until the first oil crisis began in 1973.

Six carburetors: 1979 Honda CBX with six sidedraft Keihins (left), 1965 Lamborghini P400 Miura (prototype chassis) with 6 x downdraft Webers (centre) and 1970 Ferrari 365GTB/4 (Daytona) with 6 x downdraft Webers (right).

It was the development of these big four barrels which in the US reduced the place of the multiple systems to a niche reserved for some specialist machines and even the engineers admitted that for what most people did, most of the time, the multiple setups offered no advantage.  The research did however indicate they were still a selling point and because people were still prepared to pay, they stayed on the option list.  There were a handful of engines which actually needed the additional equipment to deliver maximum power but they were rare, racing derived units and constituted not even 1% of Detroit’s annual production.  Paradoxically, the main advantage of the multiple setups was economy, a six-barrel (ie 3 x two-barrel) engine running only on its central carburetor unless the throttle was pushed open.  As it was, the last of Detroit’s three-carb setups was sold in 1971, the configuration unable easily to be engineered to meet the increasingly onerous exhaust emission rules.

Eight carburetors: 1955 Moto Guzzi 500cm³ Ottocilindri V8 Grand Prix motorcycle with 8 x Dell'Ortos.  One carburetor per cylinder was long common practice in motorcycle design and the two 1959 Daimler V8s (2.5 & 4.6 litre, 1959-1969), were designed along the lines of a motorcycle power-plant, intended originally to be air-cooled and run 8 carburetors; the production versions were water-cooled and used 2 x sidedraft SUs.  The very thought of keeping eight carburetors synchronized would alarm most but clearly such intricacy doesn't scare the Italians because, in 1967, the Cooper-Maserati Formula One team, seeking that elusive quality of increased power and sustained reliability did ponder bolting a dozen Webers to what was their by then antiquated (pre-historic in F1 terms) 3.0 litre V12.  To the eternal regret of those who value mechanical complication for its own sake, that idea, like the notion of using three spark plugs per cylinder, never left the engineers' sketch pads and the more rational fuel injection was adopted.  

Lindsay Lohan admiring Herbie’s carburetor in Herbie: Fully Loaded (2005).

Before fuel-injection was late in the century used for some, most Volkswagen Type 1s (Beetles) were fitted with a single Solex carburettor although there were exceptions, some more expensive and higher performance (such things are relative) variants in Europe, Mexico and Brazil using twin Solexes.  Additionally, because it wasn’t difficult to swap in the twin carburettor units used in the Karmann Ghia (Types 14 & 34) and Type 3 cars, many were upgraded and over the years there were literally dozens of kits to create multi-carburetor induction systems using equipment from a variety of manufacturers including Solex, Weber, Dell'Orto and Kadron (Solex-Brosol).

Choke & Choker

Choke (pronounced chohk)

(1) To be unable to breathe because of obstruction of the windpipe (solid & semi-solid objects such as food or fumes or particles in the air which cause the throat to constrict); asphyxiate, strangle, suffocate, throttle.

(2) Full to the point of obstruction (usually as “choked with”); block up, bung up, clog, congest, jam, obstruct, stop up.

(3) In forestry, to seize a log, felled tree etc with a chain, cable, or the like, so as to facilitate removal.

(4) In engineering, any mechanism which, by narrowing or blocking a passage, regulates the flow of air, gas etc.

(5) In fluid mechanics (of a duct), to reach a condition of maximum flow-rate (immediately before the choke-point), due to the flow at the narrowest point of the duct becoming sonic.

(6) In electronics, an inductor having a relatively high impedance, used to prevent the passage of high frequencies or to smooth the output of a rectifier (also called the choke-coil.

(7) In combat sports (wrestling, karate etc), a type of hold (of the throat) which can result in strangulation.

(8) A constriction at the muzzle end of a shotgun barrel which varies the spread of the shot.

(9) To enrich the fuel mixture of an ICE (internal-combustion engine) by diminishing the air supply to the carburetor (a choke a specific component of a carburetor althouh the term is used loosely).

(10) To make or install a choke in a device.

(11) To stop by or as if by strangling or stifling:

(12) To stop by filling; obstruct; clog

(13) To suppress a feeling, emotion, etc (often as “choke up”, choke down” or “choke back”).

(14) In sport, to grip a bat, racket, club etc) farther than usual from the end of the handle (to shorten the grip).

(15) To suffer from or as from strangling or suffocating.

(16) To become obstructed, clogged, or otherwise stopped.

(17) To become too tense or nervous to perform well (used most often in competitive sport, specifically in the sense losing by performing badly at a critical point, when in a winning position).

(18) In slang, the inedible centre of the head of an artichoke.

1150–1200: From the Middle English choken & cheken, a variant of achoken & acheken, from the Old English ācēocian (to suffocate), from the Old English ċēoce & ċēace (jaw, cheek) and cognate with the Old Norse kōk (gullet) and the Icelandic kok (throat) & koka (to gulp).  The transitive verb emerged in the late thirteenth century and by the late 1300s was being used in the sense of “to stop the breath by preventing air from entering the windpipe”; “to make to suffocate, deprive of the power of drawing breath” and that was used of persons as well as swallowed objects.  In that. It was a shortened form of the twelfth century acheken, from Old English ācēocian, probably from the root of ċēoce & ċēace (the spelling ceoke was also used).  In the narrow technical sense “choking” has been the cause of death of a number of rock stars including the guitarist Jimi Hendrix (1942-1970), Led Zeppelin’s drummer John Bonham (1948-1980) and AC/DC’s vocalist Bon Scott (1946-1980) although in all cases the critical “inhalation of vomit” which induced them to choke to death was caused by substance abuse.  In the same vein, the singer Janis Joplin suffered a fatal head injury in a fall while affected by drugs and alcohol; all these deaths may be regarded as “death by misadventure”.  The alternative forms choak & choake are obsolete; chock is dialectal.  Choke is a noun & verb, chokage & choker are nouns, choking is a noun & verb, chokeable is an adjective and choked is a verb & adjective; the noun plural is chokes.

The intransitive verb dates from the early fifteenth century when it was used to mean “gasp for breath”, in line with the figurative use in agriculture & horticulture (the Biblical notion of weeds stifling the growth of useful plants a Biblical image).  The term “choked up” (overcome with emotion and unable to speak) seems first to have been documented in 1896, the use possibly related to the earlier use of the word (choke-pear (1530s), crab-apple (1610s), choke-cherry (1785)) of fruits with an untypical degree of astringency and it’s thought the botanical link inspired Dr Johnson (Samuel Johnson (1709-1784)) to define the figurative use as “any aspersion or sarcasm, by which another person is put to silence”.  The noun chokage emerged in the 1840s while the term chokehold (tight grip around a person's neck to restrict breathing) was first used in 1962. The idea of a “choke” in sport in the sense of “losing by performing badly at a critical point, when in a winning position” dates from 1907 and comes from baseball where it referred to a “clutch hitter” (the hitter at the plate upon whom winning depended) “choking up” and failing to perform; the phrase “to fail in the clutch” similar in meaning.

Interchangeable choke for shotgun.

Although (except in the odd, curious niche), rendered obsolete by fuel injection, the carburetor is a device which continues to exert a fascination in those with a fondness for mechanical intricacy and an inclination to tinker.  Carburetors are devices used on ICEs (internal combustion engine) to produce the mix of fuel (typically petrol (gas)) & air required for combustion and in mainstream use they lasted into the twenty-first century.  Most carburetor were fitted with a choke, an instrument controlled by the driver and what the choke did was provide an enriched mixture (ie more fuel, less air) to make starting easier from cold.  The term “choke” was already known in engineering but the most direct comparison was probably from ballistics, chokes (some types described as “adjustable chokes”) fitted to shotguns as early as 1875.  A shotgun’s choke is a device (or constriction) at the muzzle end of the barrel which controls the spread (or pattern) of the shot as it exits the barrel.  By altering the spread, chokes allow shooters to customize their gun's performance for different purposes (ie hunting, target shooting, home defense et al).  When a shotgun cartridge is discharged, the begin to spread out immediately upon leaving the barrel (in slang they’re sometimes called “scatter guns” and a choke modifies this spread by narrowing or widening the diameter of the barrel at the muzzle.  This affects the density and size of the shot pattern at different distances.

Pellet field streams using various chokes.

In the industry, the classification of chokes is determined by the extent to which they narrow the barrel and the most common types are: (1) Cylinder: these are not fitted with a choke and thus there’s no constriction; they’re most suitable for short-range shooting. (2) Improved Cylinder: These have a slight constriction, thereby offering a moderately wide spread suitable for short and medium range targets. (3) Modified: A variation of the Improved with more constriction, lengthening the effective range.  (4) Full: Thos provides a narrow bore, creating a tight pattern for long-range accuracy, (5) Extra full: As the name implies, an even smaller bore, popular for turkey hunting or precision shooting.  There are also (1) fixed chokes (integral with the barrel and thus unchangeable) and (2) interchangeable chokes which are detachable inserts a shooter can swap according to the shooting to be done.

1971 Chrysler (Australia) Valiant Charger R/T E38 (choke knob arrowed).

Confusingly, although it was almost always the case a choke would be part of a carburetor (cable activated by a control in the driver’s cabin), the word “choke” was also used of carburetors in a different context and potentially more confusingly still, when used thus, it was often synonymous (and sometimes used interchangeably) with “throat”, “barrel” and “venturi”.  In the now arcane world of carburetors inhabited by those familiar with the things, this casual use isn’t a problem because the four words are known to refer to different components, although even experts rarely dwell on the details: (1) The throat is the main passage (there can be as many as four in a single carburetor, not necessarily all of the same bore (although if there are four they are usually sized in pairs)) through which air flows and a throat encompasses the entire internal air pathway.  (2) The barrel is the cylindrical tube that houses the throat, venturi and in many cases the throttle valve; the barrel is the structural element through which the air and fuel are mixed and delivered.

Weber-style IDF twin choke downdraft carburettor with chrome ram tubes (left), pair of Weber 40 IDA triple barrel carburetors (centre) and Holley Dominator 4500 1150 CFM Square Bore four barrel carburetor with fitting kit.

In US use, “barrel” is the most common way of describing carburetors (two barrel, four barrel) and the standard abbreviation is “bbl”.  That seems inexplicable by the usual conventions of English but is a historic legacy from the petroleum industry where it was used to denote a barrel of oil.  The specification and paint scheme of early oil barrels were standardized by Standard Oil, and the abbreviation “bbl” became widely used to signify a “standardized blue barrel”, hence the apparently superfluous “b”; over time, “bbl”, became the universal shorthand for barrel, even outside the oil industry. (3) The venturi is a specific narrowing of a carburetor's throat or barrel, the primary purpose of which is to create a pressure drop due to the “venturi effect” (a phenomenon of fluid dynamics) in which as air flows through the narrowed section, its velocity increases and its pressure decreases (surface friction at this scale not significant).  The pressure drop induced by the venturi effect draws fuel from the fuel bowl into the air stream for mixing and atomization.  (4) Choke in this context is simply another way of saying “barrel” and the choice is dictated by local conventions of use; In Europe it was common to speak of a “two choke” carburetor whereas if used by a US manufacturer this would be a “two barrel”.  There was trans-Atlantic respect for this tradition and in both communities tend to use the correct terminology of each other’s devices although hot-rodders in the US did like slang such as the evocative “four-holer”.  Despite that, Ford did for a while muddy the waters by using the terms to 2V and 4V (ie 2 venturi & 4 venturi) to refer both to two & four barrel carburetors but also the two different cylinder heads designed for each.  People got used to that but it did latter induce confusion elsewhere when 2V & 4V came to be understood as “two valve” & “four valve” (ie per cylinder).

Model Tessa Fowler (b 1992) wearing fabric chokers.

Choker (pronounced choh-ker)

(1) In fashion, a piece of jewelry or ornamental fabric, worn as a necklace or neckerchief, snug around the throat (use based on the “choker chain” used to restrain dogs).

(2) One who, or that which, chokes or strangles.

(3) A person administering a choking device (depending on context, either a class or machine operator or a murderous strangler).

(4) A neckcloth or high collar.

(5) As choker chain, a dog collar designed to pinch or squeeze the dog or other animal when the leash is pulled.

(6) In forestry, a chain or cable used to haul logs to a transportation point.

(7) In slang, any disappointing or upsetting circumstance.

(8) In slang, the traditional clerical collar worn by Christian clergy.

(9) In slang, a cigarette.

(10) A person who pratices autoerotic asphyxiation or paraphilia, a practice where someone temporarily cuts off their own air supply by means of a ligature or some other sort of self-asphyxiation device during sex or masturbation.

(11) In sport, one who “chokes” (losing by performing badly at a critical point, when in a winning position).

1550s: The construct was choke + -er.  The –er suffix was from the Middle English –er & -ere, from the Old English -ere, from the Proto-Germanic -ārijaz, thought most likely to have been borrowed from the Latin –ārius where, as a suffix, it was used to form adjectives from nouns or numerals.  In English, the –er suffix, when added to a verb, created an agent noun: the person or thing that doing the action indicated by the root verb.   The use in English was reinforced by the synonymous but unrelated Old French –or & -eor (the Anglo-Norman variant -our), from the Latin -ātor & -tor, from the primitive Indo-European -tōr.  When appended to a noun, it created the noun denoting an occupation or describing the person whose occupation is the noun.  The noun emerged in the 1550s in the sense of “one who chokes” an agent noun from the verb and from 1848 it was used to mean “large neckerchief”.  The use to mean “a kind of necklace worn against the throat” dates from 1928.  Choker is a noun; the noun plural is chokers.

Lindsay Lohan with choker at Moschino Fashion Show, London, June 2014.  A choker is a decorative accessory worn around the neck and differs from a necklace in that it sits higher (typically mid-way up the neck) and fits snugly.

In fashion, choker is a clipping of “choker chain”, a dog collar designed to pinch or squeeze the dog or other animal when the leash is pulled.  Chokers can be for any material (fabric, leather (studded varieties popular), metal etc), and are sometimes adorned with jewels or logos.  There are also chokers with LED (light-emitting diodes) displays in a variety of colors which are powered by a small button-battery, rechargeable via a USB (universal serial bus) port.  According to a normally reliable source (Urban Dictionary), a choker is (1) a symbol used by emos to convey a desire to engage in self-harm or even suicide or (2) a way certain young ladies advertize their especial fondness for and skill in performing fellatio (this should be treated as a gaboso (Generalized Association Based On Single-Observation).  In the BDSM (Bondage, Discipline (or Dominance) & Submission (or Sadomasochism) community, chokers are sometimes used as the “submissive collar”, given by dominants as a symbol of possession and sometimes augmented with a leash for purpose of public display.

Anna Teshu (b 1994, right), in choker and on leash with ex-boyfriend Nathan Riely (b 1988. left) while role-playing as a dog and handler.  If consensual, the "leashed partner" thing is a kink and a genuine ALC (alternative lifestyle choice), albeit one which has attracted some criticism, some suggesting the "leashed" are suffering from "false consciousness", an idea explored in other contexts by both Karl Marx (1818-1883) and Sigmund Freud (1856-1939).

Orifice

Orifice (pronounced awr-uh-fis or or-uh-fis)

A mouth, opening or aperture, as of a tube or pipe; a mouth-like opening or hole; mouth; vent (mostly technical or medical use).

1535–1545: From the Middle English orifice (an opening, a mouth or aperture), from the Old French & Middle French orifice (the opening of a wound), from the Late Latin ōrificium (an opening (literally "the making of a mouth")), the construct being Latin ōr- (stem of ōs (genitive oris)) (mouth (and related to "oral")) + fic- (combining form of facere; facio) (to make, to do) + -ium (the noun suffix).  The root of facere was the primitive Indo-European dhe- (to set, put).  The rare adjectival form is orificial; neither orificish or orificesque apparently exist.

Miss Schilling’s Orifice

Rolls-Royce Merlin V12.

Fuel to early versions of the twenty-seven litre (1648 cubic inch) Rolls-Royce Merlin V12 engine was supplied with a carburetor, putting the pilots in the Merlin-powered Spitfires and Hurricanes at a disadvantage against the German Messerschmitt BF109 fighters which used a fuel-injected Daimler-Benz DB601 inverted V12.  In the British planes, during a negative G-force maneuver (pitching the nose hard down), fuel was forced upwards to the top of the carburetor's float chamber rather than into the combustion chamber, leading to a loss of power. If the negative G continued, the fuel would collect in the top of the float chamber, forcing the float to the bottom. This in turn would open the needle valve to maximum, flooding the carburetor with fuel, drowning the supercharger with an over-rich mixture which would shut down the engine, a serious matter in aerial combat.

Battle of Britain era Hawker Hurricane Mk IIA and Supermarine Spitfire Mk II.

Ms Beatrice “Tilly” Shilling (1909-1990) was a pre-modern rarity, a female engineer and amateur racing driver.  While employed as an engineer at the Royal Aircraft Establishment (RAE) at Farnborough she worked on the fuel delivery problem, concluding quickly the only complete solution for fuel starvation was a pressurized fuel system such as the direct injection on the Daimler-Benz V12s but that such a development would take months to design, test, manufacture and install.  However, as a stop-gap measure, she designed a flow restrictor: a small metal disc with a central orifice, looking much like a plain metal washer.  The restrictor orifice was sized to accommodate just the fuel flow needed for maximum engine power, the setting usually used during dogfights and it solved the immediate, critical, problem of the engine shutdowns following flooding.  Officially named the RAE Restrictor or RAE Anti “G” Carburetor, the device proved popular with pilots, who much preferred to call it Miss Shilling's orifice or the Tilly orifice.  The simple and elegant solution proved effective until pressurized carburetors (essentially throttle-body injection, a simplified version of the Daimler-Benz direct fuel injection) were developed which permitted even inverted flight.  With a backpack of RAE Restrictors, she toured RAF airfields on her motor-bike instructing and assisting the maintenance crews with the installation of the devices.

RAE Anti "G" carburetor restrictor plate instruction sheet.

Ms Shilling was a serious engineer making an important contribution to the war effort and was not amused by the nick-names for her invention but reportedly regarded it as something typical of minds of men and carried on with her work.  The orifice was but a footnote in the history of the Merlin and the Allied war effort but did typify the improvisation and speed with which British industry developed "quick & dirty" solutions, especially in the early days of the war.

Magnum

Magnum (pronounced mag-nuhm)

(1) A large wine bottle having a capacity of two ordinary bottles or 1.5 liters (1.6 quarts).

(2) In ballistics, a magnum cartridge or firearm (a loaded with a larger charge than other cartridges of the same calibre).

(3) A firearm using such a cartridge.

(4) Used generally, unusually great in power or size:

1788:  From the Latin magnum (“great, large, big" (of size), "great, considerable" (of value), "strong, powerful" (of force); of persons, "elder, aged"), neuter of magnus (large), from a suffixed form of the primitive Indo-European root meg- (great).  The original use in English was to describe the large wine-bottle, then usually containing two quarts.  As the name of a powerful type of handgun, it was first registered in 1935 by the US company, Smith & Wesson of Springfield, Massachusetts.  Outside of ballistics, the most common use is now probably “magnum opus" (masterpiece, a person's greatest work, literally "great work", applied, in literature, music, art and (sometime a little liberally) popular culture.  Magnum is a noun; the noun plural is magnums or magna.

The magnum’s place in the hierarchy of Champagne bottles.

Magnum ammunition

Lindsay Lohan in habit with Smith & Wesson .500 Magnum, Machete (2010).

Released in September 2010 at the Venice Film Festival and distributed internationally by Sony Pictures, Machete would probably be more highly regarded if the full-length feature had lived up to the promise created by the artfully-edited trailer.  Probably about twenty minutes too long, the critical consensus suggests Machete was a violent, shallow, repetitive and probably unnecessary addition to whatever was the sub-genre of exploitation it inhabited.  That said, the production values were thought high enough for those who like this sort of thing to be able to look forward to it as one of the more enjoyable movies of the summer of 2010.

Smith & Wesson .357 Magnum.

A magnum cartridge is one with a larger case size than the standard cartridge of the same calibre and case shoulder shape.  The now generic term is derived from Smith & Wesson’s Original .357 S&W Magnum, introduced in 1934; magnum ammunition containing either or both additional propellant or a heavier projectile but the term is a bit of an anomaly in the business of ballistics.  Although in the terminology of firearms, most jargon is explicitly defined, “magnum ammunition” has no precise codified set of standards, instead being just an indication of the possession of more powerful characteristics than other loads of the same calibre and shape.  One revolver which has found a niche is the .22 Magnum.  Although in the public imagination it lurks behind the bigger calibre loads (.357, .44, .50), it's a practical device which can use the .22 LR (Long Rifle) shell and manufacturers offer them with a cylinder capacity of 10 or 12, more than many semi-automatics.  Retailers recommend them for non-expert shooters because with a minimal recoil when firing, they're easy to handle and the rule is it’s better to have a .22 LR that hits its target than a .44 Magnum that misses it. 

Smith & Wesson .500 Magnum.

Smith & Wesson’s original .357 Magnum was introduced in 1934 in response to the growing availability of bullet-proofing technology in both automobiles and the ballistics vests used for personal protection.  It was an attempt to provide greater penetrative power without the need to increase the bore with the consequential increase in the size and weight of weapons.  Predictably though, the arms race had begun, and in the decades which followed, magnum loads would become available for a wide range of calibres, hand guns and long arms as well as shotguns, the classic .44 Magnum, later made famous in popular culture, released in 1954.  It didn’t stop there, increasing demand for the .44 convincing Smith & Wesson to develop the .500 Magnum, currently the most powerful handgun load generally available and one marketed, in addition to its other attractions, to those who might find it more convenient than a rifle for hunting big game.  The size, weight and recoil however mean it’s not suitable for all and in the US, .500 is anyway the legal limit for handgun loads.  In US law, it’s a rare restriction.

.460 Weatherby Magnum.

For that reason, even Smith and Wesson do recommend that unless one plans to hunt elephant at close range or expect to confront a charging wild boar, loads like the .357 Magnum are better for what most people do most of the time.  The same caution applies to the Magnum loads for rifles, the .375 Magnum often nominated by experts as the perfect compromise for all but the most extreme applications.  Indeed, it was loads like the .375 Magnum which eliminated most of the need for the famous old-style “elephant guns” like Holland & Holland’s .600 Nitro and the .458 and .460 Magnum cartridges of the 1950s were necessitated only by regulations governing big-game hunting in Africa mandating a load above .400.  Despite that, demand for the heavy calibres remains strong, Holland and Holland, after introducing a canon-like .700 Nitro found demand so unexpectedly strong that they resumed production of the long retired .600.  While it seems unlikely heavier loads will be thought practical, that may not matter, there being some evidence many of the .700 Nitros are sold to collectors, never to be fired.

That said, Austria’s Pfeifer firearms created supply to meet what demand there may be.  The Pfeifer .600 Nitro Express Zeliska single-action revolver weighs over 13 lb (4.85 kg) and is  22 inches (.56 m) in length, the cylinder section alone weighing 4.5 lb (17 kg).  Although generating a muzzle energy of 7,591 foot pounds (33.7 kn), paradoxically, the weight of the gun actually limits the recoil, making controlled shooting possible although, practice is essential.  With a cylinder capacity of either five .600 Nitro or .458 Winchester Magnum rounds, it's able to fire a 900 grain, .600 some 2000 feet (600+ m).  At release, Zeliska listed the revolver at US$17,316 and because each .600 Nitro Express round costs about US$45, it’s an expensive hobby.

The Magnum Concilium

Dating from Norman times, the Magnum Concilium (Great Council) was an English assembly eventually composed of senior ecclesiastics, noblemen and representatives of the counties of England and Wales (and later of the boroughs too) which was from time-to-time convened to discuss matter of state with the king and his advisors (sitting as the Curia Regis (King's Court; a kind of predecessor to the Privy Council and later the cabinet).  The Magnum Concilium evolved into the Concilium Regis in Parliamento (the parliament of England), the first generally thought to be the so-called "Model Parliament" of 1295, which included archbishops, bishops, abbots, earls, barons, and representatives of the shires and boroughs.  The evolution wasn’t linear, power in the land a constant struggle between king and parliament, the authority of both fluctuating as the politics of the day effed and flowed.  Nor was the parliament a united force, shrewd kings knowing how to exploit divisions between the parliamentary factions but by the reign of Edward II (1284-1327; as Edward of Caernarfon, King of England 1307-1327), the nobility was ascendant, the Crown compliant and the rest essentially irrelevant.

Execution Of Charles I, 1649 (circa 1850) by an unknown artist.

Under Edward III (1312–1377; as Edward of Windsor, King of England 1327-1377), the modern bicameral structure (a House of Commons & a House of Lords), became clear and the authority of Parliament grew although the Lords remained by far the most powerful because that was where the economic resources were concentrated.  That reality was reflected by the practice, under the Plantagenet kings, of the summoning of the Magnum Concilium being something exclusively ecclesiastical & aristocratic, the representatives of the commons rarely in attendance.  After Henry VII (1457–1509; King of England 1485-1509) convened the Magnum Concilium on several occasions in the late 1400s, for various reasons, its participation in the governance of England went into abeyance until, in 1640, Charles I was advised to summon the Magnum Concilium after he’d dissolved the Short Parliament in order to raise money because his misrule and wars of adventure had bankrupted the state.  The king got his money but his private army was soon at war with the parliamentary forces of both Scotland and England and those wars did not for him go well.  Before the decade was over, he would be beheaded.  The Magnum Concilium has not since met but experts in English constitutional law have confirmed it still exists and can, at any time, be summoned by the Crown.

Chrysler’s 440 Magnum Six-Pack

383 Magnum V8 with cross-ram induction in in 1960 Dodge Dart Phoenix D-500.

Chrysler’s family of big-block wedge V8s lasted from 1958 until 1978 but, although the label is often commonly applied, not all were designated “Magnum”.  The first Magnum was a high-performance version of the B-series 383 cubic inch (6.3 litre) V8 (which differs from the later RB 383), the highlight being the option of a (long) cross-ram inlet manifold with two four-barrel carburetors.  It was only Dodge which used the Magnum label; the equivalent power-plant in a Plymouth was called a Commando (there were adjectives sometimes added) and in a Chrysler, a TNT.

1970 Dodge 440 Magnum Six-Pack.

Introduced in 1969, the highest evolution of the RB Magnum were the 440 cubic inch (7.2 litre) versions built with three Holley 2300 series two-barrel carburetors instead of the more commonly seen single carburetor induction (which were on the 440 almost exclusively in four-barrel form).  The early versions used an Edelbrock manifold cast in aluminum but supply difficulties forced Chrysler also to cast their own in cast-iron to meet demand.  Although obviously a high-performance variation, marketed by Dodge as the 440 Magnum Six-Pack, the engine was engineered to use only the centre 250 cubic feet per minute (7 m³) carburetor under normal throttle loads, the outer two 370 cfm (10.4 m³) units used only if summoned (something like the "demand" superchargers on Weimar-era Mercedes-Benz, the kompressor activated only when the throttle was pushed wide-open, high in the rev range).  If one could resist the temptation of the sudden onrush of power, the Magnum Six-Pack could be quite economical by the admittedly slight standards of the time, simply because, when driven with restraint, it was percolating along with only the one two-barrel carburetor active.

440 Magnum Six-Pack in 1970 Dodge Challenger.

Internally, the Six-Pack Magnums differed from the single carburetor engines in the use of stiffer valve springs borrowed from the 426 Street Hemi, stronger rocker arms (strengthened connecting rods were added in 1970), molybdenum-filled piston rings and flash chromed valves (which is why simply adding the six-pack induction system to a standard 440 can end badly).  Better to cope with the additional stresses imposed by those high-tension springs, the camshaft lobes and lifter faces were blueprinted to equalise the loads, the lifters rotating to distribute wear equally across the surfaces subject to friction.  With its compression ratio upped from 10.1:1 to 10.5:1, upon release, the Magnum Six-Pack was rated at 390 bhp (290 kw), dropping slightly to 385 (287) when some minor anti-emission adjustments were made in 1971.  At around half the price of Chrysler’s much-vaunted Street-Hemi adaptation of the race engine, the Magnum Six-Pack was a bargain, at least matching the Hemi in most aspects of performance until speeds above 120 mph (190 km/h) were attained, along with a longer manufacturer’s warranty and lower insurance costs, at least for some.  It was good while it lasted but in the US, 1971 was the swansong for both the Magnum Six-Pack and the Street-Hemi, emission regulations and an astonishing increase in the cost of insuring the things crushing demand.

1971 Jensen FF Series III, one of 15 made from a total production (1966-1971) of 320.

Across the Atlantic however, the Six-Pack Magnum did enjoy a brief afterlife after being driven extinct in the US.  Jensen, in the throes of phasing out their acclaimed but unprofitable all-wheel-drive FF, were looking for a flagship which could be created quickly and cheaply, ruling out the mooted convertible which wouldn’t appear for some years.  With their planned new F-Type unlikely to be on sale before 1973, the need was for something which demanded neither much development time nor an onerous budget.  As it was, circumstances contrived to ensure the F-Type was stillborn after a single prototype was built.

The much admired louvers on 1972 Jensen SP.  So much did the look appeal a louvered bonnet (hood) of a slightly different design was later made available on the standard Interceptor.

Jensen had for years been building their Interceptor & FF models with the Chrysler RB engines and had even flirted with the idea of doing a run with the Street Hemi, a project aborted when the costs of adaptation became apparent.  In late 1970, Jensen’s need for something was communicated to Chrysler which, by happy coincidence, had a batch of Magnum Six-Pack engines which had been gathering dust in a Canadian warehouse since being effectively orphaned by the new US emission control legislation.  Within days, agreement was reached, Jensen taking delivery of the first tranche of the batch which, although unable to be sold in the US, were legal just about everywhere else.  The mechanical specification settled, discussions then turned to other features which could be included to enhance the car’s status as a premium product.  Because it was the 1970s (and there's really no other excuse), without much discussion, it was agreed to glue on a vinyl roof; that many others did the same thing is no defense but it wasn't obligatory; of the 232 SPs, there were 185 with a black vinyl roof, 15 in tan, two in white while three subversives ordered the "Duotone" paint option with the roof painted a contrasting color.  More defensible was the inclusion of a high-quality and very expensive Learjet eight-track cartridge stereo system and, to provide some continuity with the FF, it was decided to use that model’s blue-themed badges rather than the red used on the Interceptor.  Also, interestingly, it was during these initial discussions that a fully louvered bonnet (hood) would be included in the specification but there’s no indication there was any concern about additional engine-bay heat, the louvers apparently just a styling device to evoke memories of earlier eras when they were common on high-performance machinery.  There was little debate about the name; several people had suggested SP was the obvious choice.  In December 1970, the first prototype SP was built although the intricacies of the triple carburetor engine weren’t entirely new to Jensen’s engineers, having a few months earlier fitted one to an Interceptor.  Assessment of the prototype proved the adaptation was as straight-forward as expected, the minor issue of the additional clearance demanded by the big air-filter effected by a quick fix to the filter housing.

1971 Jensen SP at the Geneva Motor Show, March 1972.  Just twelve were built in left-hand drive configuration because the SP engine couldn't meet the new US emission standards, thereby precluding sales in the market most receptive to thirsty machines.

Scheduled for release in the northern autumn of 1971, Jensen’s original plan had been to announce the SP as part of their new range including the Mark III versions of both the Interceptor and FF but the realities of the future made apparent the mixed-messaging was a bad idea.  The SP was intended to be the new top-of-the line model so announcing it with an updated version of the doomed yet still more expensive FF made little sense, the Mark III FF created only as a way to ensure the last fifteen FF body-shells (the all-wheel drive configuration necessitated a longer wheelbase) could be utilised.  Almost all FF marketing was thus terminated and the emphasis switched to the new two-model range with the SP sitting atop which meant the Mark III FF, which would become one of the Jensens most prized by collectors, went at the time almost unnoticed.

1972 Monteverdi 375/4.

Beginning its tour of the motor show circuit, the new flagship was greeted with subdued interest by the motoring press which viewed the SP as the hot rod Interceptor it was and which, while entertaining in a occasionally brutish (and rather un-Jensen like) sort of way, was not as intriguing as the soon-to-be lamented FF, the prowess of which had so astonished all who drove it, exploring for the first time the revolutionary possibilities of anti-lock braking and all-wheel-drive.  Nevertheless, the performance did impress, a top-speed of 143 mph (230 km/h) being reported although it was noted the even bigger and heavier 375/4 limousine made by boutique Swiss manufacturer Monteverdi had been clocked just a little faster and it used the 440 with only a single four barrel carburetor.  Still it was fast enough and nobody complained the SP lacked pace.

Jensen SP press release, 5 October 1971.

What did elicit complaint was the manner in which that speed sometimes arrived.  The tremendous delivery of power at full-throttle was praised but the lack of predictable response lower in the rev-range attracted criticism, the additional carburetors kicking in sometimes unexpectedly and not always when the car was heading in a straight line.  Issues with hot-starting were also apparent and even the otherwise much admired multi-louvered bonnet was found not the be without fault, the slats apparently changing either the properties of the metal or the reaction of the shape to the fluid dynamics of air-flow; at speed, the bonnet would “slightly shiver, almost as though improperly fastened” and testers, used to the cocoon-like stability of the Interceptor and FF, found it disconcerting.  While none of the reviews were damning, nor were they much more than polite.  Surprisingly, the only mention testers made of the standard air-conditioning (A/C) was that it worked well but it deserved a longer note because Jensen was the only factory which fitted A/C to a triple-carburetor 440, Plymouth & Dodge in the US never offering the option.  Monteverdi enjoys a similar distinction, it's Hai (two of which were built in 1971 & 1973) the only vehicle powered by Chrysler's 426 cubic inch (7.0 litre) Street Hemi V8 to have factory fitted A/C.

1972 Jensen SP engine bay.

Worse was to come as customers started reporting problems, the first being the issue of under-bonnet heat.  Although a big machine by European standards, the engine bay of the Jensen was smaller than anything to which it’d been fitted in the US and, even with the louvers helping to ventilate the space, it got very hot in there and this quickly affected the carburetors which had never before been exposed to such extremes; parts warping as the metal heated and then cooled, causing air-gaps to emerge, making accurate tuning, vital with multiple-carburetion, impossible.  The factory was soon receiving reports of engines which refused to idle and, due to the inherent nature of the Holly 2300 carburetor design, engines would run too rich after a week or so of nothing more than normal driving.

Chocolate fiend Lindsay Lohan with Magnum (ice cream) backdrop.

For a small company like Jensen, it was a major setback.  The company had built the Interceptor's reputation on reliability and ease of ownership essentially by piggy-backing on the back of the bullet proof Chrysler V8s and TorqueFlite transmissions it had begun using in the Interceptor's predecessor, the CV8.  The approach, adopted by many in this era, appealed to buyers not sufficiently seduced by the bespoke charm and mechanical intricacies of the continental competition to wish to deal with the cost and inconvenience of the more demanding maintenance schedules (and expensive parts catalogue) listed by Ferrari, Lamborghini & Maserati.  Like the MGA Twin-Cam (and for that matter the later Jensen-Healey), the SP was a classic case of insufficient product development and testing, examples of which littered the post-war UK industry.  Perhaps there was complacency because (1) multiple carburetors were nothing new to British manufacturers and (2) the Six-Pack Magnum had a good record of reliability in the US.  However, three Hollys on a big-block Chrysler turned out to behave differently to three big SUs on a Jaguar XK-six.                  

1970 Dodge Super Bee 440 Magnum Six-Pack with typical girlfriend of typical buyer.

The occasional quirk of the Magnum Six-Pack was not unknown in the US but there the nature of the thing was well-understood; it was a hot-rod engine bought by those who wanted such things, most owners young, male, mechanically adept and often anxious to tinker under the hood (bonnet).  The Jensen buyer was a wholly different demographic, mostly older, affluent men who either had rarely seen under a bonnet or hadn’t looked for many years and their expectations of a car which was twice as expensive as Jaguar’s V12 E-Type were very different to those youthful Californian baby boomers had of their hotted-up taxi cabs.  Used to the effortless, if thirsty, behavior of the Interceptor, some found their SPs, the high-performance of which most could rarely explore, were behaving like brand new, very expensive old clunkers.

Jensen FF with typical mistress of typical buyer.  This is not a period photograph but is English model Harriadnie Beau Phipps (b 1993) in a 2014 photo-shoot for Oxfordshire-based UK operation Bavarez which specialized in restoring & modifying Interceptors. 

Weeks of testing and experiments with all sorts of adjustments proved pointless.  In Jensen’s workshops it was always possible to produce a perfectly running SP but, after sometimes as little as a week in the hands of owner, it would be back, displaying the same symptoms and in the end, Jensen admitted defeat and offered the only solution guaranteed to work: remove the triple induction system and replace it with the Interceptor’s faithful Carter Thermoquad four barrel carburetor.  That alleviated all the drivability issues but did mean that having paid their £6,976.87, a premium of a thousand-odd pounds over the anyway expensive Interceptor, the emasculated SP became an Interceptor with a vinyl roof, an eight-track cartridge player and a vibrating bonnet.  The factory’s records suggest between a quarter and a third of buyers opted for the Theromquad fix and some refunds were paid to the especially unhappy.

Last gasp: 1974 Jensen Interceptor convertible.

Although Jensen had known, because the Magnum Six-Pack was out of production, the SP was not going to have a long life, it had been hoped it would fulfil its role until the new F-Type was expected to be released in 1973.  However, having built 208 SPs, Jensen didn’t take up their option on what was still in Chrysler’s Canadian remainder bin and, once the stock already delivered was exhausted, the SP was allowed quietly to die.  Between September 1971 and July 1973, 231 Jensen SPs were completed with one final example built in October, a special order from someone who really wanted one.   

1972 Jensen-Healey publicity shot.

It was the start of a run of bad luck that would doom also the Interceptor and the entire company: (1) Development issues would beset the F-Type which would never see the light of day, (2) the Jensen-Healey (1972-1976) sports car which had seemed so promising turned into an expensive flop and (3) the first oil shock in 1973 rendered the Interceptor and many of its ilk suddenly big, thirsty dinosaurs and not even the release in 1974 of a much-admired convertible version could rescue things.  Bankruptcy loomed and by 1976 the end came.  However, flawed but charismatic English cars, decades on, sometimes enjoy second acts and SPs are now much prized with a small industry devoted to restoring them to their six-barreled glory, modern materials and techniques of insulation & cooling now able to transform them into something as well-behaved as any Interceptor.