Following his success in pre-war trials events, Sydney Allard launched two new cars, the K1 and J1. Both cars were two seat sports cars designed for road and competition use. Thanks to their simple bodies the K1 and J1 weighed very little and were powered by V8 engines which offered plenty of performance.

The K1 was the larger of the two models and came with a 3.6 litre Ford "flat head" V8 engine. For simplicity the gearbox and other mechanical items were also common to the Ford V8 models which meant they were robust and well proven. The K1 model was more popular than the shorter J1 and continued until 1948. 151 cars were built.