Dan Gurney was a much respected road racer in the 1960s. The creative thinking that his grandfather showed when he developed the hospital gurney, which is named for him, came into play when Dan had his own original idea.
Colin Chapman was the most advanced of the forward-thinking Formula One builders, so Gurney sought him out to develop a car that could beat the long-favoured Indy roadsters. It was obvious to Dan Gurney that the classic Indy Roadster with it's Offenhauser engine was antiquated when compared with the constantly evolving concepts in Formula One cars. He fought to interest the Ford Motor Company in the project, and eventually acquired a V8 engine from them that had been created especially for this assault on the Indianapolis 500.
Bobby Johns drove the unique car in the Indy 500 in 1965, and crossed the line in seventh place, in a race that was won by Jim Clark. Clark drove the same Lotus 38 to second place the following year, having clocked a qualifying pace of almost 165 miles per hour.
Not only was the Lotus 38 the first British car to win the Indianapolis 500, it was the first mid-engine car to win. The engine was behind the driver and in front of the rear axle, so technically it was not rear-engined, but the engine is between the front and rear axles, so it's mid-engined. The car's superiority at the classic brickyard included an Indy straight-line speed record that was unbeaten for more than twenty years. The Lotus 38 sounded the death knell for the Offy front-engined roadster. http://en.wikipedia.org/wiki/Lotus_38
After an initial USA victory at the 1961 US Grand Prix, Colin Chapman bore down on a challenge – to win the legendary Indianapolis 500 race. The Lotus 38/1 was the result of the design intent, and in 1965 Jim Clark drove it to victory at the brickyard, ahead of a field made up of some mid-engine and some front-engine competitors. The following year there was just a handful of front-engine cars, and one year later, all Indy 500 competitors carried their engine behind the cockpit.