The Austin-Healey 100 is a sports car that was built by Austin-Healey from 1953 until 1956.
Based on Austin A90 Atlantic mechanicals, it was developed by Donald Healey from his Nash-Healey 2 door sports car, which had Nash mechanicals instead, to be produced in-house by his small Healey car company in Warwick. Healey had Tickford build a single Healey Hundred for the 1952 London Motor Show, and the design impressed Leonard Lord, managing director of Austin, who was looking for a replacement for the unsuccessful A90. Body styling was by Gerry Coker, the chassis was designed by Barry Bilbie with longitudinal members and cross bracing producing a comparatively stiff structure upon which to mount the body, innovatively welding the front bulkhead to the frame for additional strength. In order to keep the overall vehicle height low the rear axle was underslung, the chassis frame passing under the rear axle assembly.
Lord struck a deal with Healey to build it in quantity; bodies made by Jensen Motors were given Austin mechanical components at Austin's Longbridge plant. The car was renamed the Austin-Healey 100.
The "100" was named by Healey for the car's ability to reach ; its successor, the better known Austin-Healey 3000, was named for the almost 3000 cc displacement of its engine.
Apart from the first twenty cars, production Austin-Healey 100s were finished at Austin's Longbridge plant alongside the A90 and based on fully trimmed and painted body/chassis units produced by Jensen in West Bromwich—in an arrangement the two companies previously had explored with the Austin A40 Sports. 14,634 Austin-Healey 100s were produced.
The 100 was the first of three models later called the Big Healeys to distinguish them from the much smaller Austin-Healey Sprite. The Big Healeys are often referred to by their three-character model designators rather than by their models, as the model names do not reflect the mechanical differences and similarities well.
BN1
The first 100s (series "BN1") were equipped with the same undersquare bore and stroke 2660 cc I4 engines and manual transmission as the standard production A90, but the transmission was modified to be a three-speed unit with overdrive on second and top.
Girling drum brakes were fitted all round. The suspension used modified Austin A90 components in order to be as cost effective as possible, steering was by Austin's worm and peg system. Front suspension was independent, double wishbone using coil springs and at the rear a rigid axle with semi elliptic leaf springs.
A BN1 tested by The Motor magazine in 1953 had a top speed of and could accelerate from 0– in 11.2 seconds. A fuel consumption of was recorded. The test car cost £1063 including taxes.
A total of 10030 BN1s were built from May 1953 until replaced by the BN2 model in August 1955. A 1954 BN1 (chassis #446766*4) is on permanent display in the Bonneville Salt Flats exhibit at the Simeone Foundation Automotive Museum in Philadelphia, PA, USA.
BN2
The BN2 was fitted with a real four-speed manual transmission, still with overdrive on the top two gears. Other features that distinguish the BN2 from the BN1 are the slightly larger front wheel arches, different rear axle and being the first 100 with optional two-tone paint. The BN2 was available initially in Carmine Red which was replaced with Reno Red, Spruce Green, Healey Blue, Florida Green, Old English White, Black, and approximately 50 Gunmetal Grey cars. Two-tone options were: White/Black; Reno Red/Black; Healey Blue/White; Black/Reno Red; and Florida Green/White
By January 1956 production was running at 200 cars each month and sales in California 150 cars each month.
The final BN2 was built in July 1956, with a total of 4604 BN2s produced, including the 100M. Many BN-2 and 100-M Austin Healeys compete in vintage events like the Pittsburgh Vintage Gran Prix.
100M
A high-performance 100M model was introduced in 1955 with larger carburettors, a cold air box to increase engine air flow, high-lift camshaft and 8.1:1 compression pistons. It produced at 4500 rpm. The front suspension was stiffened and the bonnet gained louvres, along with a bonnet belt. Approximately 70% of 100Ms were finished with a two-tone paint scheme, including one White over Red and another in Black over Pink for display at the 1955 London Motor Show. In all, 640 100Ms were built by the factory.