Celebrating 70 Years of the Austin Healey 100M – Le Mans Legend Turns 70

Austin Healey 100M 70th Anniversary – Le Mans Legacy

2025 marks the 70th anniversary of the legendary Austin Healey 100M, a true icon of British motoring heritage. Born from Donald Healey's passion for racing, the 100M combined timeless design with racing pedigree, capturing the hearts of enthusiasts since its debut at the London Motor Show (Earls Court) on 19 October 1955 (the show ran 19–29 October 1955). Join us as we revisit the history, evolution, and unique characteristics of the celebrated Austin Healey 100M, and discover how A H Spares can help keep these cherished classics on the road.
Note: while many BN1/BN2 cars were upgraded with the dealer/factory-supplied Le Mans Engine Modification Kit, the designation “100M” refers specifically to the 640 factory-built BN2 cars produced between 5 September 1955 and 16 July 1956.

In short: dealer-fitted Le Mans kits were common, but only the BN2 factory run is officially recognised as the 100M.

Why the 100M existed — Le Mans pedigree

The Austin Healey 100/4 earned its stripes in endurance racing, most notably with a strong showing at the 1954 24 Hours of Le Mans (12th overall, 2nd in class). That success directly inspired a limited, factory-built road car with competition-proven upgrades: the 100M. The package bundled the louvered bonnet with leather strap, a special cold air box feeding larger SU H6 carburettors, a higher-lift camshaft and an increased compression ratio — a focused evolution designed to bring a taste of Le Mans to the road.

Iconic Two-Tone Paint Schemes of the Austin Healey 100M

One of the most visually striking features of the Austin Healey 100M was its distinctive two-tone paint scheme, with approximately 70% of the 640 factory-built cars proudly sporting this stylish look. Popular combinations included Old English White over Black, Reno Red over Black, Healey Blue over White, Black over Reno Red, and Florida Green over White, each carefully chosen to accentuate the car's flowing lines and sporting character.

Perhaps the most memorable, however, was the unique Black over Pink combination used exclusively on the car displayed at the 1955 Earls Court Motor Show (19–29 October). This one-of-a-kind Healey later competed in the Bahamas Speed Week and has since been meticulously restored, preserving its original eye-catching colours. These vibrant colour schemes set the aesthetic tone for later Austin Healey models, influencing the iconic two-tone combinations used on the BN4 through BJ8 series.

Here’s a table listing all the colours available across these models. For those curious to see the remarkable Black over Pink colour scheme in full glory, a photograph and detailed history of this special car can be found here on Bring a Trailer

Factory 100M vs Retrofitted 100s – Spotting the Difference

Understanding the distinction between factory-built and converted 100Ms is essential for collectors and enthusiasts alike:

• Documentation: Factory-built cars are recorded with the British Motor Industry Heritage Trust, establishing authenticity. For additional verification, many owners consult the Worldwide 100M Le Mans Registry.
• Bonnet and Badge: Original 100Ms always featured a factory-fitted louvered bonnet and leather strap, along with the distinctive "M" badge.
• Performance Equality, Historic Authenticity: While retrofitted models replicate the performance, genuine factory-built examples hold greater historic and market value.

Factory 100M identification — quick checklist

• Chassis basis: BN2 only for factory 100M.
• Documented as 100M: Heritage Certificate and build ledgers explicitly record 100M specification.
• Louvered bonnet & leather strap: fitted from new on factory cars; look for correct period workmanship and associated fixings.
• Induction system: cold air box with plaque, intake hose, and SU H6 carburettors (factory specification and locations matter).
• Engine internals: higher-lift camshaft and higher-compression pistons (approx. 8.1:1) matching period 100M spec.
• Chassis dynamics: stiffer front springs and uprated anti-roll bar as per 100M package.
• Instruments & details: 140 mph speedometer commonly found; two-tone paint schemes were frequent but not definitive on their own.
• Corroboration: period records from the 100M/“Le Mans” registry and provenance history help validate factory build.

Note: Dealer-modified BN1/BN2 cars can match performance when built to the kit specification, but factory 100M provenance is determined by documentary evidence and the as-built feature set above.

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