Four more Special Test cars were built in 1954. All had the four-port engine (plus an oil cooler to alleviate an oil temperature issue noted at Le Mans) along with a David Brown close-ratio gearbox and new Dunlop disc brakes, fitted at all four corners.
Lance Macklin and George Huntoon took the first of these cars to the 12 Hours of Sebring in March, managing first in their class and third overall despite a broken rocker arm that left them down one cylinder. Their strong performance actually proved a handicap in future events — at the Mille Miglia in May, race officials insisted the Hundreds had to run in the over-2-liter sports car class, pitting the Healeys against far more powerful competitors like Ferrari and Maserati. The company faced a similar challenge at Le Mans, where the disc-equipped Hundreds were pushed into the sports car prototype class. Healey opted to withdraw, issuing a public statement lamenting the growing gap between racers and production cars.
That summer, two Special Test cars were prepared for another round of record attempts at Bonneville. One of the entries was the previous year’s record-setter, fitted with disc brakes and a new 142 hp (106 kW) engine. The other had a heavily modified streamliner body, another Gerry Coker creation, with a bubble canopy and a dramatic but purely cosmetic dorsal fin. Intended to reach 200 mph (320 km/h), the streamliner had a Shorrock supercharger, giving 224 hp (167 kW) on a mixture of Benzole, methanol, and castor oil. While the streamliner set a new array of speed records, it didn’t quite hit the target; its best speed was 192.7 mph (310.2 km/h). The endurance car achieved 53 records of its own, maintaining more than 132 mph (212 km/h) for over 24 hours.
That fall, Healey announced that the Sebring car would be the basis for a new limited-production sports racer, christened 100S. Intended for racing homologation and competition-minded owners, it had a reinforced frame and an all-aluminum body with a new grille and a one-piece Perspex windscreen. The bumpers were deleted to save weight while the fuel tank was enlarged from 12 to 20 Imperial gallons (14.4 to 24 U.S. gallons; 54.5 to 90.9 liters). Four-wheel Dunlop disc brakes were standard, as was a close-ratio Morris gearbox, although overdrive moved to the options list. The 100S engine was similar to the earlier Weslake-designed four-port unit, but had revised manifolds, a high-compression aluminum head, a lightened flywheel, and dual exhausts. Output was 132 hp (98 kW) and 168 lb-ft (228 N-m) of torque, which combined with the lighter weight and close-ratio gearbox to give ferocious performance: 0-60 mph (0-97 km/h) in less than 8 seconds with a top speed of more than 125 mph (201 km/h). List price was just under $5,000.
The higher-revving engine was far from smooth and there were problems with the aluminum cylinder heads, clutches, and exhaust manifolds, but the 100S was a true dual-purpose sports racer, taking class victories at both Sebring and the Mille Miglia in early 1955. Unfortunately, that summer, one of the Special Test prototypes was also involved in the worst racing tragedy of the decade. On the 35th lap at Le Mans in June, Healey driver Lance Macklin’s car, registration NOJ 393, was rear-ended by Pierre Levegh’s Mercedes 300SLR. The Mercedes flipped over and struck a retaining wall, sending its engine and debris hurtling into the crowd and then catching fire. Macklin was not injured, but Levegh and about 80 spectators were killed with dozens more injured. Macklin’s car was impounded and not returned to Warwick until more than a year later.
Production of the 100S continued for about four months after Le Mans, ending in November. Including the Special Test cars, only 55 were built, including a prototype fixed-head coupe, which Donald Healey kept for his own use until the early 1960s.
BN2 AND 100M
By September 1954, production of all the earlier Healey models had ended, allowing the staff in Warwick to concentrate on the Special Test cars and other Austin-Healey projects. Fortunately, the Hundred was selling far better than all the previous cars combined: production totaled more than 10,000 cars through mid-1955. Quite a few were raced, with respectable results; one car even won its class in the 1955 Mobilgas Economy Rally.
The early Hundred, known today by its chassis code, BN1, underwent various running changes through its run, from new two-piece side screens to the substitution of the hypoid-bevel axle from the Austin Westminster for the original A70/A90 unit. In August 1955, all Hundreds received the four-speed taxi gearbox, along with wider front brakes and a longer body-side swage line, facilitating the use of two-tone paint. Those changes prompted a new chassis code: BN2.
Later that year, the standard BN2 was supplemented by a new model, the 100M. Introduced at the Earls Court show in October, the 100M was presumably intended to provide a cheaper replacement for the 100S, featuring a louvered bonnet, minor suspension modifications, and the Le Mans engine kit, giving 110 hp (82 kW). Priced 10% higher than the standard car, the 100M accounted for 1,159 units through mid-1956, roughly 25% of BN2 production.
Unfortunately, production was down significantly. Although the Hundred had outsold the Triumph TR2, the new TR3 was proving a more difficult opponent. Introduced in October 1955, the TR3 had revamped styling and additional power, giving it a small but significant advantage over the Austin-Healey. It was still more than $300 cheaper than the Hundred and even offered optional 2+2 seating. To match that competition, Healey would have to make some significant changes.
THE AUSTIN-HEALEY 100-6
One idea for improving Austin-Healey sales was a long-wheelbase model, known at Warwick as the L-type. Prompted by Donald Healey’s concern that lack of passenger space was costing sales, the L-type had a 2-inch (51mm) longer wheelbase, providing room for a pair of occasional rear seats. Gerry Coker also explored a number of possible updates to the Hundred’s styling, including enclosed headlamps, small tailfins, and louvers in the front fenders to exhaust engine heat (later adopted by some of the competition cars).
According to Geoff Healey, serious thought was also given to standardizing the 100S engine across the line, which would have given the Hundred a clear performance edge over the TR3. However, Austin management was not enthusiastic; the 100S engine was expensive to produce, requiring a unique block casting to match the aluminum head’s altered stud positions. BMC preferred to modify the Hundred to accommodate the newer Morris-designed C-series six, which was replacing the big four in BMC’s bigger sedans.
Installing the six in the Hundred chassis was not a complex exercise, but the engine itself left much to be desired. While a six-cylinder engine might seem to provide a marketing advantage over the four-cylinder TR3, the C-series was slightly smaller in displacement than the big four and actually had less torque. Worse, the six was considerably heavier than the four — dry weight was over 600 lb (277 kg) — which eroded the Hundred’s power-to-weight ratio.
Hoping to cast the new engine in a good light, the Healeys decided to take two six-cylinder cars to Bonneville in August 1956. The original 1953–54 record-setter was fitted with aerodynamic body extensions and an oval grille (once again courtesy of Gerry Coker), along with a heavily modified C-series engine with a new six-port head and separate intake manifold. The 1954 streamliner was also modified extensively and fitted with a supercharged six, producing 292 hp (218 kW).
On the Salt Flats, both cars blew their engines repeatedly, but the endurance car nevertheless set numerous speed records, including a six-hour average of more than 146 mph (235 km/h). The supercharged streamliner, driven by Donald Healey himself, reached speeds of up to 203 mph (327 km/h) — short of the 217 mph (349 km/h) originally projected, but still an impressive figure. It would be the last run for Donald Healey, who had recently turned 58. Afterward, the Healeys’ insurance company, understandably nonplussed by the whole affair, finally persuaded him to leave the risky stuff to others.
The six-cylinder production car went on sale that fall. Christened Austin-Healey 100-6 (and known today by its BN4 chassis code), it completely replaced the four-cylinder BN2. The BN4 was 6.5 inches (165 mm) longer than the BN2 and had the longer-wheelbase chassis and 2+2 seating. Except for its new grille and hood scoop, the BN4 looked much the same as the four-cylinder car, but weight was up about 240 lb (110 kg). Most of that was on the nose, requiring stiffer front springs and a thicker anti-roll bar. As a result, the six-cylinder cars had heavier steering than the fours and a new propensity for initial understeer and dramatic final oversteer.
Press response to the 100-6 was lukewarm. Instead of giving the Healey an edge over the TR3, the six-cylinder engine seemed to be a step backward. While the six-cylinder car’s top speed was similar to the four’s, 0-60 mph (0-97 km/h) acceleration took about a second longer than before. Worse, the BN4 still had drum brakes, while the Triumph now offered standard front discs, something the Hundred had yet to offer except on the 100S. Sales of the 100-6 were not significantly better than those of the BN2, amounting to about 5,000 units a year.
In response, Healey started work an alternative: a smaller, cheaper Austin-powered sports car, codenamed Q1 (and later ADO 13). It would emerge in May 1958 as the first Austin-Healey Sprite. The Sprite was one of the last projects Gerry Coker worked on for Healey; in 1957, he moved to the U.S. to become a body engineer for Ford.