1955 Austin-Healey 100M

Automotive developer and racer Donald Healey, looking to reach a broader sports car market, developed this iconic British sports car in the early 1950s using a 4-cylinder Austin A90 engine. An initial success, British Motors Corporation saw the value of a strong competitor to the Triumph TR Series and took over production.

The Austin-Healey 100 made its debut at the 1952 London Motor Show. The attractive little car caught the attention of the then-acting director of Austin, Leonard Lord, who wanted to add 'Austin' to the name through a partnership deal, proposed by Donald Healey. After funding was in place, the production of the Austin Healey 100-4 began, from 1953 until 1956. These little roadsters were successful both on the road and the track, being campaigned at circuits worldwide by both factory racecars and privateer entrants. Two mildly modified examples were entered in the Le Mans 24-Hour Race, finishing in 12 and 14th overall, and second in class. The name 'Le Mans' was later used for a bolt-on tuning kit offered through Austin-Healey dealers, allowing private owners to have cars brought to a specification approaching that of the works entries. The kit added a pair of 1¾-inch SU HD6 carburetors plus a special inlet manifold and cold air box, high-lift camshaft, stronger valve springs, and distributor with alternative ignition advance curve. The kit brought horsepower from the standard 90 to 100 bhp.

Beginning in October of 1955, the conversion became available from the factory on the successor BN2 model in the form of the 100M. The 100M added the LeMans kit plus high-compression pistons, stiffer front anti-roll bar, special Armstrong front dampers, and a louvered bonnet. Power rose to 110 bhp and top speed was rated at 120 mph.

The exact number of BN1s converted by their owners is not known. However, 1,159 examples - mostly BN2s - were built or later modified to 100M specifications between 1955 and 1956. Of those, approximately 640 were completed at the factory, and around 544 were exported to the USA. It is believed that around 200 survive.

The 1955 Austin-Healey 100 Sport Roadster had a base price of nearly $3,000. The 100M specification brought the price to almost $3,300 while the 100S (Sebring) was $5,000. The 100S was a racing version that had an aluminum body without bumpers, a modified engine with Weslake cylinder heads, and all-around disc brakes. Just 50 examples of the 100S were built in 1955. The highly tuned engine offered 132 horsepower and 150 lb-ft of torque.

Few changes were made to the 1955 Healey except for the addition of a four-speed gearbox in place of the original three-speed unit. Standard equipment included knock-on wire wheels, twin carburetors, 4-speed with manual-activated overdrive, and a defroster.

by Daniel Vaughan | May 2019