A few weeks ago Paul Fearnley documented Colin Chapman’s last Formula 1 cars, including the twin-chassis Lotus 88.

Chapman was renowned for pushing the limit and breaking new ground, which he also did during his short foray into Indycar racing and specifically the Indy 500 between 1963-69.

Chapman’s Lotus 25-based 29 Indycar of 1963 was at the heart of a massive revolution, which roiled Indycar racing through the ‘60s. Moving the engine from front to rear was the first step, followed immediately by the arrival of turbocharged engines, wings, aerodynamics and modern low-profile tyres.

All these things combined to dramatically increase lap speeds at Indianapolis and produce cars that were changed out of all recognition in only a matter of years.

After perfecting the Lotus 29 concept with Jim Clark’s 500-winning type 38 in 1965, Chapman designed a new BRM H-16-powered car for ’66. But the BRM Indy engine was hopelessly underpowered and Team Lotus raced modified Ford-powered 38s at Indianapolis in 1966 and ’67.

For 1968 Chapman joined the turbine revolution pioneered the previous year by Parnelli Jones in Andy Granatelli’s STP turbine car. The type 56 Lotus turbine of ’68 was a wedge-shaped car and Joe Leonard and Graham Hill qualified the cars first and second at Indianapolis with Leonard looking a likely winner of the 500 until a fuel pump drive broke with less than ten laps to go.

USAC subsequently put severe restrictions on the intake area for turbine engines, rendering them uncompetitive, so Chapman decided to tackle building a completely new turbo Ford-powered Indycar for 1969. The type 64 was a four-wheel-drive, wedge car with big wings front and rear. The engine was mounted backwards so it could drive the centrally mounted 4WD Lotus/Hewland/ZF/Ferguson transmission.

Conceived by Chapman, the 64 was detailed by Maurice Phillippe and three 64s were built over the winter of 1968-’69. Two of them were for Team Lotus drivers Graham Hill and Jochen Rindt and the third was destined for Mario Andretti to drive for Andy Granatelli’s STP team run by veteran chief mechanic Clint Brawner.

Inevitably, the cars were late and Andretti was able to conduct only one test session in America prior to the month of May at Indianapolis. The lone test revealed that the 64 had plenty of potential but was lacking in many regards. Chapman flew home from the test with a long job list of more than 200 items and Brawner’s team started the season with one of their more dependable Brawner/Hawks with which Andretti would win both that year’s 500 and the USAC championship.

The Lotus 64 at the 2008 Goodwood Festival of Speed

Jim McGee was Brawner’s crew chief and McGee recounts some of Brawner’s many worries about the 4WD Lotus. “One thing Clint didn’t like was that the hubs and all the running gear were Formula 1 stuff,” McGee says. “Chapman’s argument was that it was 4WD and the stuff that was on the car was for two-wheel drive so the rear axles were only taking sixty percent of the load of a normal Formula 1 car. He said they were plenty husky. But we didn’t like the way they were built and put together and we told Chapman, but he said it was fine. He said he had to keep the weight down.”

Brawner and McGee took the 4WD Lotus and the dependable Mk III Hawk to Indianapolis. “The first week we ran the Lotus and it was fast,” McGee says. “But we had problems with it. Clint said we had to keep an eye on it and every night we pulled the hubs off and sent them down to Magnaflux to check them.”

Despite their worries Andretti was able to set the pace, substantially quicker than anyone else, Hill and Rindt included in the factory 64s. “We were four mph quicker than the second-placed car and we still hadn’t received the rear tyres designed for that car,” McGee says. “We were running four front tyres because Firestone hadn’t been able to produce the rear tyres. They were going to arrive for qualifying.

“That car would have out-qualified everybody by four or five mph. It was that quick. Mario said you could drive it down into the corner with one hand. With 4WD there was no understeer. It would just pull the front end around the corner.”

McGee says Andretti (above in practice) enjoyed an advantage over Hill and Rindt because of his experience with big boost turbocharged engines. “Rindt and Hill didn’t really know how to make up for the lag in the turbos,” McGee remarks. “In those days, the turbos had a big lag in response and Rindt and Hill were right foot brakers and Mario wasn’t. He was a left foot braker so he could use his left foot to keep the boost and the revs up.

“There was no way those guys were going to compete with Mario because of their driving style. They didn’t have the oval experience or the experience with turbos that Mario had.”

Disaster struck in the middle of the week of practice prior to Pole Day, however, when one of the Lotus’ rear hubs failed, exactly as Brawner had worried. Andretti spun backwards into the wall and the car caught fire as it slid down the fence. Mario was lucky to escape with relatively minor burns to his face and lips but the Lotus was written off.

The crash turned out to be the end of the road for Chapman and Team Lotus at Indianapolis. The three Lotus 64s were withdrawn and the 4WD Lotus never raced, nor would Chapman ever be seen again at Indianapolis or any other Indycar race.

After the accident Andretti reverted to the tried and tested Hawk for qualifying and the race (above). Starting from the middle of the front row Mario led the opening five laps before falling back to nurse climbing water and oil temperatures. He allowed AJ Foyt and his team-mate Roger McCluskey to set the pace in their Coyote-turbo Fords and also fell behind Lloyd Ruby’s Mongoose-turbo Offy.

But Foyt and McCluskey ran into engine trouble and Ruby made a mistake in the pits, attempting to leave before his refueling hose was detached resulting in a race-ending fire. In the end Andretti was able to win easily, crossing the line almost two minutes ahead of Dan Gurney. It was Andretti’s first and last Indy 500 victory made memorable to the wider world by Andy Granatelli’s embrace and kiss of Mario in victory circle.

By that time Chapman was long gone from Indianapolis. He had other fish to fry.

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