The first generation of Austin-Healey 100 was introduced in 1953 for the 1954 model year. The first generation of 100 was known as the BN1. The BN1 was fit with a 90hp 2.7L inline four engine mated to a 3 speed transmission. The most notable BN1 variant was the 100S, a special limited edition race-derived variant. The first generation 100 was in production until 1955, when the Second Generation Austin-Healey BN2 was unveiled.