A review of The Austin-Healey 100/4 BN2 Sports Car, covering development, important features, and technical data of this the first model in the range.

In this Article, I offer a nostalgic look at the Austin-Healey 100/4 BN2, one of an elite group of classic cars, which was manufactured during the period 1955 to 1956.

In August 1955, production of the Austin-Healey 100/4 BN1 sports car was finally brought to a close after 10,030 cars had been built.

Although production of its successor, the 100/4 BN2, began that same month, it was not officially launched until presented at the London Motor Show in October of that year.

Like the BN1, it was powered by a 2.6 litre, 4-cylinder in line, overhead valve engine.

However, the BN2 now featured:

  • Enlarged drum brakes all round
  • The original three speed gearbox, with first gear blocked off, was now replaced with a four speed unit, together with overdrive on the top two gears
  • Front wheel arches that were increased in size to a small extent
  • A different rear axle
  • A two tone colour scheme for the body panels was an optional extra

These optional colour combinations included: White and Black, Reno Red and Black, Healey Blue and White, Black and Reno Red, Florida Green and White.

Austin-Healey 100S

Designed specifically for rallying and the race track, the 100S sports car, where “S” referred to Sebring, produced 132 bhp at 4700 rpm.

Appearing in 1955, it was built with aluminium body panels.

A total of 50 cars were built, together with a further five works cars that were hand built at the Warwick factory.

Instead of a cast iron head, the 100S used one made of aluminium.

To minimise weight, there was no overdrive unit, hood, or bumpers, a smaller grille was used, and the windscreen was made of plastic.

It was the first production car to include Dunlop disc brakes all round.

The result of these measures was a weight saving of some two hundred pounds.

Nearly all the 100S’s body panels were painted with the two tone American racing colours of White and Lobelia Blue, although one car was painted solely in Black.

The 100S competed at many famous racing venues, such as Le Mans, Sebring, and Mille Miglia.

It was, in fact, a replica of a special works car, driven by Stirling Moss, in which he finished in third position in the 1954 Sebring twelve hour race.

Austin-Healey 100M

Following on from the 100S, the most illustrious and desirable early variant of the BN2 was the uprated 100M Le Mans sports car.

Appearing in 1956, it offered greater performance and a variety of distinctive external features derived from experience gained on the race track.

100M Specification included:

  • The bonnet contained louvered vents with a leather retaining strap
  • Two larger 1.75 inch H6 SU carburettors
  • Wire wheels that were painted in silver
  • A low, adjustable windshield which could be folded flat for the sporty driver
  • Compression ratio increased from 7.5 to 8.1:1
  • A high lift camshaft and high compression pistons
  • A cold air box and air tube to improve air flow to the carburettors
  • A low restriction intake manifold
  • A modified distriutor
  • Stiffened independent front suspension using wishbones and coil springs, and an anti roll torsion bar
  • Live rear axle with leaf springs, and an anti movement track bar

These modifications increased output from 90 bhp of the BN2 to 110 bhp, with 154 ft/lb of torque.

Some 70 % of these cars were painted in the two tone system, including two unique specialities – one in White and Red, and another in Black and Pink, the latter being used in a display capacity at the 1955 London Motor Show.

In total, there were 640 factory made 100M’s, and all were BN2 models from 1956.

Apart from the high compression pistons, the components used to create the 100M were available as a Le Mans Modification Kit, which could replace existing components in a BN1 or BN2, so increasing the output to 100 bhp.

Donald Healey’s Warwick factory upgraded some 519 additional cars with Le Mans kits after they had left the production line.

Since these kits, and any components, were available from BMC, then any modifications could be done by either an Austin dealer or the customer themselves.

Total 100M’s built at both Longbridge and Warwick was 1,159.

Production of the BN2 ended in August 1955 when it was replaced by the Austin-Healey 100-6.

This marked the end of the Austin-Healey 100/4 BN2

Perhaps this stroll down memory lane might have answered, or at least shed light on, a possible question:

Which Austin-Healey Sports Car is Your Favourite?

However, should this question still remain unanswered, I will be reviewing, in some detail, in future articles within this website, the entire range of Austin-Healey sports cars which were featured in the memorable era spanning 1953 to 1972.

I hope you join me in my nostalgic travels “down sports car memory lane”.

Austin-Healey 100/4 BN2 Sports Car
Contact us

We're not around right now. But you can send me an email and I'll get back to you, asap.

Questions, issues or concerns? I'd love to help you!

Click ENTER to chat