The car that came to be known as the Lotus Mark II was created in 1949, while Colin Chapman was serving with the RAF. For his second car Chapman built on the knowledge gained from building and competing in the Lotus Mark I, so he again used the widely available and inexpensive Austin 7 chassis as a starting point. He boxed in the chassis rails and replaced the cross members with stronger tubular braces. He swapped the Austin engine for a Ford engine and transmission, first from a Ford 8, then from a Ford 10, but retained the Austin 7 rear axle. To be able to use a wider tyre, Chapman adapted Ford pressed-steel wheels. He modified the engine as far as the club rules would allow.