Austin-Healey 100/6 BN4 Sports activities Automotive
A evaluation of The Austin-Healey 100/6 BN4 Sports activities Automotive, masking improvement, vital options, and technical knowledge of this the primary mannequin within the vary.On this Article, I supply a nostalgic take a look at the Austin-Healey 100/6 BN4, considered one of an elite group of basic automobiles, which was manufactured throughout the interval 1956 to 1959.The File Breaking CarsThe StreamlinerIn 1956, two sports activities automobiles have been taken to the Bonneville Salt Flats in Utah as a part of Donald Healey’s dream of travelling at greater than 2 hundred mph.The primary automobile was based mostly on a 1954 Austin-Healey BN1, powered by a supercharged, 2639 cc, BMC C-Collection, 6-cylinder engine with a 4 pace gearbox.Owing to its form, it was often called the “Streamliner”. In reality, this engine, in its normal kind, would energy the forthcoming Austin-Healey 100/6 sports activities automobile.The supercharged engine was modified by Austin till it had developed 292 bhp at 5000 revs. At this level, they have been assured that the automobile was able to reaching 217 mph.One weak point of the automobile was its bevel rear axle which, owing to the intense energy generated, may fail if the automobile accelerated too quick.Earlier than being dispatched to America, the automobile obtained in depth aerodynamic testing in a wind tunnel. Because of this, it was agreed to take away the automobile’s 1954 rear fin with the intention to enhance stability.On ninth August 1956, throughout the first take a look at run, because the automobile reached 200 mph, the supercharger failed amidst an enormous explosion.After receiveing substitute elements from England, the automobile was repaired at a neighborhood service station.On 21st August, Donald Healey set off on the primary of two obligatory runs, one in every path.
Through the first run, he achieved 204 mph earlier than the supercharger, as soon as once more, blew up.After fast repairs, he reached 197 mph on the second run which gave him a median pace of 201.1 mph. He had achieved his dream of reaching 200 mph.The Endurance CarThe second automobile taken to Bonneville in 1956 was often called the Endurance Automotive, and was an Austin-Healey BN2 sports activities automobile fitted with an extended nostril.It used a normal 2639 cc engine with a six port head, three twin choke Webber carburettors, a compression ratio of 10:1, and developed 160 bhp.Nevertheless, additional improvement on it raised the output to 164 bhp at 5500 rpm when working on a mix of equal proportions of methanol, benzole, and premium grade petrol.On ninth August 1956, when engine testing started, issues with vapour lock induced the trials to cease.On 14th August, additional issues with misfiring have been encountered.Subsequently, with issues resolved, the engine was fitted into the physique, constructed by carmakers Jensen, with the cockpit tailored to resemble a single seat racer.Carroll Shelby and Roy Jackson-Moore, between them, broke the 150 mph barrier with the Endurance automobile.The 2 file breaking makes an attempt have been carried out to coincide with the launch of the brand new Austin-Healey 100/6 sports activities automobile in September 1956.The Endurance automobile was painted within the two tone color scheme of Healey Blue and White, and sported an oval grille with wavy horizontal bars that have been to be integrated within the forthcoming launch.The 100/6 BN4The 92 bhp generated by the fundamental C-Collection engine was considered inadequate to energy the brand new 100/6 particularly since its predecessor, the 100/Four, produced 90bhp, and was some 330 kilos lighter.Consequently, on account of additional work on the engine, output was elevated to 102 bhp at 4600 revs.This preliminary model of the 100/6 BN4 sports activities automobile had solely two inlet ports which, mixed with horizontal 1.5 inch H4 SU carburettors, made for tough engine respiratory.Though Zero-60 mph time was lower than that of the 100/Four, the brand new automobile had a a lot smoother engine, with good mid vary torque, which made for easy lengthy distance excessive pace driving.In late 1957, the BN4 obtained a brand new cylinder head with a six port aluminium inlet manifold, and two bigger 1.75 inch HD6 SU carburettors.Along with bigger valves and a compression ratio raised to eight.7:1, the engine now developed 117 bhp at 4700 rpm, with an enchancment in each acceleration and high pace.This six port head was the results of the 1956 file breaking automobiles.In 1956, the 100/Four BN2 sports activities automobile was phased out simply as BMC was within the means of rationalising its vary of engines as follows: A-Collection being 850 cc, B-Collection being 1500 cc, and C-Collection being 2600 cc.For the reason that Austin A90 and Wolseley 6/90 saloon automobiles have been presently utilizing a C-Collection, 6-cylinder engine of 2639 cc displacement, it was recommended that this unit may change the prevailing 2660 cc, Four-cylinder unit used within the BN2.100/6 BN4 Specification:
2639 cc, 6-cylinder, overhead valve engine
A two port cylinder head initially, later changed by a six port
Two HD6 SU carburetttors
4 pace gearbox with overdrive on the highest two gears
Impartial entrance suspension with a dwell axle on the rear
Hydraulic drum brakes all spherical
Windscreen was now mounted and will not be folded down
Two occasional rear seats (2+2 model) till early 1958
For the reason that new 6-cylinder engine was bigger than its substitute, a bonnet scoop was added so that the radiator, which had now been moved ahead, was away from the bonnet.Moreover, with the intention to prolong the attraction of the automobile, Donald Healey added two occasional rear seats. Because of this, it was mandatory to extend the size of the chassis by two inches.The two+2 model was discontinued in early 1958, and was solely supplied as an non-compulsory additional, because the two seater model grew to become the extra fascinating.Aside from 284 items constructed with proper hand drive for the house market, all 100/6 manufacturing was exported to the US.Within the latter a part of 1957, the manufacture of the BN4 moved from the Longbridge manufacturing unit to the MG facility at Abingdon.Manufacturing of the BN4 resulted in 1958, when it was changed by the 2 seater, 100/6 BN6 variant.This marked the top of the Austin-Healey 100/6 BN4Perhaps this stroll down reminiscence lane might need answered, or a minimum of make clear, a potential query:Which Austin-Healey Sports activities Automotive is Your Favorite?Nevertheless, ought to this query nonetheless stay unanswered, I shall be reviewing, in some element, in future articles inside this web site, your entire vary of Austin-Healey sports activities automobiles which have been featured within the memorable period spanning 1953 to 1972.I hope you be part of me in my nostalgic travels “down sports car memory lane”.