|Shadow Mk III Chevrolet|
Ahead of the 1971 Can-Am season, the two men that had been responsible for the previous campaigns most unconventional machines, Don Nichols and Peter Bryant, joined forces. Nichols' AVS Shadow had grabbed headlines mostly because of the very small wheels used, while Bryant came very close to really challenge the established teams with his titanium 'Bryant Ti22'. Unfortunately he ran out of funding to run the innovative machine, forcing Bryant to offer his services to others. The British designer also brought driver Jackie Oliver with him to Shadow.
Despite the lack of success in 1970, Nichols was not yet ready to let go of the minimal frontal area philosophy. He did compromise a little by switching to Goodyear Formula 1 rubber. These tyres were not quite as tiny as the Firestones used on the original Shadow but still small by Can-Am standards. This concession allowed Bryant to design a more conventional car that actually allowed the driver to properly sit in the car. The only part carried over from the Mk I Shadow were the rear inner wheel shells, which were used for the front wheels on the Bryant designed Shadow Mk II.
Unlike on the Ti22, Bryant used mostly aluminium for the monocoque of the new Shadow. Titanium was used but only small sections like the rear engine mounts. The Mk I suffered from perpetual brake problems due to the very limited space available for the discs inside the tiny wheels. Although there was more room now, Nichols and Bryant decided to use in-board brakes just like Colin Chapman had done on the 1970 Lotus 72 Formula 1 car. Bryant did have his concerns about the reliability of the shafts used to connect the discs to the wheels; a failure could have catastrophic consequences.
Other than the location of the front brakes, the suspension followed convention. The increased height of the car also allowed the radiator to be fitted in the nose. Power came from the dominant Chevrolet big block V8, which was mated to a Weismann gearbox to make for an all-American car. The new Shadow was tightly wrapped in a very square and narrow fibreglass body, which featured a front wing over the radiator intake and a strut-mounted wing behind the rear axle. To ensure a clean flow of air to the rear wing, Chaparral sourced vertical engine-intakes were used.
Unfortunately the new Shadow Mk II was not ready for the Can-Am season opener at Mosport, forcing the team to postpone the debut until the second race. The lack of time to properly prepare for the season would hunt the team throughout the year as niggling reliability issues would continue to play up. When it worked the car was remarkably competitive with Oliver qualifying in the top five in all but one of the eight races the team competed in. He placed second on the grid at Road America and finished third at Edmonton, which was the second and final time the Mk II actually lasted the distance.
Encouraged by the pace shown, Bryant continued development of the existing design over the Winter. He had finally convinced Nichols to drop the low profile philosophy altogether, which allowed him to use a much improved suspension geometry and larger wheels. The single front-mounted radiator was replaced by two separate radiators mounted on either side of the driver. These were fed with fresh air through channels in the body that originated under the front wing. Although the same tub was used, the extensive changes warranted the change of type name to Shadow Mk III.
In pre-season testing, Oliver was considerably faster than he had been with the earlier Shadow and also a bit quicker than the McLaren M8F that had been the 1971 benchmark. The arrival of the turbo-charged Porsche 917s had nevertheless raised the bar considerably. Oliver once again managed to rival the V8-powered machines on pace but the reliability woes were still not over. He did manage to convert the car's intrinsic speed into a second at Mid-Ohio and third at Donnybrooke early in the season.
A second car was completed halfway through the season, which allowed the team to experiment with a turbo-charged version of the big-block V8. Although very powerful, it certainly did not help improve the Shadow's reliability record. One of the car's issues concerned the Weismann gearbox and eventually Nichols gave up on his all-American philosophy and pragmatically allowed for a British Hewland gearbox to be fitted. All these changes did not help bring in results for Oliver and his alternating team-mates Carlos Pace and Bobby Allison.
Expanding into Formula 1, Shadow hired experienced designer Tony Southgate ahead of the 1973 season. Along with the F1 car he also designed the team's new Can-Am car from a clean sheet. This effectively brought an end to Bryant's involvement in Can-Am racing, which showed plenty of promise but ultimately did not deliver the much desired victories. Those did come for Shadow in 1974 when Jacky Oliver won the title in the Southgate designed DN4, be it against a depleted field.
Article by Wouter Melissen, last updated on July 16, 2012
Add your comments on the Shadow Mk III Chevrolet