Austin Healey 100S

We have said before that not all Austin-Healeys were created equal and one model in particular was pretty special, with a capital S.

Part of the agreement with Leonard Lord on the formation of the Austin-Healey (see Issue 2) was that the Donald Healey Motor Company (DHMC) would undertake a competition programme for the new marque, financed by Austin.

The first twenty Austin-Healeys were assembled by the DHMC at Warwick and four of these have become known as Special Test cars. Three of these were prepared for the 1953 Le Mans 24 hour, and two ran the distance with success.

Soon after, engine specialist Harry Weslake was brought in to look at improving the car’s 2660cc four-cylinder engine. With push-rods, inlet and exhaust ports all on the same side of the cylinder head it didn’t make for efficient breathing. Weslake designed a new eight-port aluminium cylinder head, moving the inlet /exhaust ports, plugs and other electrics to the opposite side from the push-rods.

Other changes, including the strengthening of the block and Nitrided crankshaft and higher compression pistons, resulted in the new engine being significantly different from the standard Austin-Healey engine.

Coupled with the fitting of larger H6 1¾” carburettors with a joint cold-air box, the improvement was significant, with power rated at 132bhp at 4,700rpm compared with 90bhp from the standard 100 engine.

US Success

Donald Healey was very clever at promoting his cars and was early to recognise the greatest potential for them was in the US.

While the initial competition foray for America was at the Bonneville Salt Flats in 1953, it was the Sebring 12-Hour the following March that took Healey’s greatest interest, as the race was also foremost on the minds of potential Austin-Healey purchasers.

The winter period of 1953/54 was put to good use, with cars being developed featuring the revised engine, Dunlop disc brakes all round, a David Brown four-speed close-ratio gearbox, upgraded differential and a cast alloy oil cooler/filter.

One car was entered as an Austin-Healey 100 by the DHMC at Sebring in 1954 and while it looked like a standard 100, beneath the metal it was a very different vehicle. Despite running on three cylinders at the end of twelve hours it finished in third place.

In recognition of this success DHMC built a small number of replicas, which became known as the Austin-Healey 100S (Sebring). Gerry Coker, who styled the original 100, was given the task of redesigning the original shape, which resulted in a subtle change to the front profile along with a completely new oval-shaped grille. A large stylised S was added to the “100” grille badge.

A distinctive colour scheme of Old English White over Lobelia Blue was chosen as the standard livery for the new model. However, chassis 3504, sold new to American actor and racing driver Jackie Cooper, was painted Spruce Green on special order. There were also two cars finsihed in red and one in black.

While the chassis and bodywork were sourced from the normal places, such as Jensen, the 100S never saw the inside of an Austin factory. Each was carefully hand-assembled at the DHMC in Warwick. To prove its authenticity, each car received a commemorative plaque on the dashboard.


Once again the British Motor Show at Earls Court, which opened on 20 October 1954, was considered the best place to launch the new Austin-Healey 100S. The first cars became available early the following year to ‘selected customers’. With the car’s release came a proper brochure with ‘Built for racing, by Racing Specialists’ emblazoned across the front: an item that today commands a pretty penny.

Besides the distinctive colour scheme the entire body was in light-alloy against the steel/alloy combination of the 100. In fact the DHMC went to extremes to lower the weight with all-alloy sub-frames, half-height Perspex windscreen, lightweight seats, no bumpers and certainly no creature comforts such as carpeting or weather equipment.

In view of the car’s competition future each was also fitted standard with a 20-gallon fuel tank with a large, quick-action external fuel filler. All 100S models left the factory in right-hand-drive.

Contemporary reports indicate that when fitted with the standard 2.92:1 differential and four-speed non-overdrive gearbox the 100S was good for at least 120mph, but speeds way in excess have been recorded. With a little fuel and no driver the 100S weighed in at 901kg, compared with the 984kg of the production 100.

Assembly of the 100S continued through to mid-1955 with the majority being sold in the US. Available records show only 50 cars were built for sale, along with five Works cars and probably two or three others to satisfy demand due to accident damage. A total of five were sold new in Australia.

As an aside, during 1954 the 100S engine was being considered as a replacement for the Austin A90 powerplant in the production Austin-Healey. However, the new BMC six-cylinder C-series engine was in the wings and the news came from Longbridge that it had to be used in as many BMC cars as possible.

To read the rest of this story, grab your copy of the magazine from your local newsagent (in Australia) or subscribe today for either the digital copy or the printed version.

The BMC Experience Issue 17. Apr-Jun 2016 Magazine


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