The Shadow

by Jim Mollitt

This article appeared in the 1972 program guide for the Monterey Castrol GTX Grand Prix.

Dethroning kings has never been an easy task. But that is the objective Don Nichols's Advanced Vehicle Systems, Inc., has again set for itself in the 1972 Canadian-American Challenge Cup Series. The kings are, of course, Team McLaren, who have ruled the Can-Am roost for the past five seasons. The AVS effort will take the shape of a concerted driving attack centered around the endurance racing virtuoso, Jackie Oliver of England.

Oliver's mount will be a new Shadow MkIII, the latest design from the pen of AVS chief designer, Peter Bryant.

For the second straight year, AVS is being supported in this quest by the Universal Oild Products company of Des Plaines, Illinois, the world's largest licenser of refining processes, and the substance behind the now familiar UOP logo seen all along the Can-Am trail.

The new UOP Shadow for 1972 represents a complete re-think of the 1971 machine, boasting no fewer than 55 detail changes over that earlier model.

Foremost in designer Bryant's mind while the car gradually took shape was the search for as much downforce (the downward thrust exerted on the car by onrushing air) as could be engineered into an ultra-low-profile body powered by a 1.8-liter engine, capable of pushing 1500 pounds of fiberglass and metal along the ground. Bryant was quite willing to sacrifice top speed in order to achieve his purpose, believing that a mile or two off the top end down a long straight is more than compensated for by the fractions of a second gained by superior speed through the turns. The result has to diminished lap times. And that is the name of the Can-Am game.

Where last year's car was immediately identifiable by its miniscule front wheels and tires - a throwback to the first tiny Shadow of 1970 - the Group Seven car connoisseur will have to look more closely for significant alterations in the 1972 version. Not that the small wheel concept has be dismissed entirely; but it was felt that the technology surrounding the theory had not yet advanced to an acceptable stage.

For its motive power, the team has chosen the limited-production Reynolds 390 Silicon aluminum sleeveless engine introduced by the McLarens in late 1970. This powerplant is referred to as "sleeveless" because the clyinder bores have nothing between them and the eight alloy pistons, unlike more conventional engines where cast iron (or other metal) liners insulate the bores from the piston's friction. the Shadow's engines, pegged at 495 cubic inches (8.1 liters) are capable of putting out better than 750 horespower at 6800 revolutions per minute, with fuel injection.

The UOP Shadow team's turbocharger development project, headquartered in Detroit, is coming along fast. The team's engine men aren't talking for the record, but rumors have it that a "blown" 495 Chevy will reliably produce more than 1,000 horsepower! And we hope to see it soon.

Turbo power seems a necessary way to go, especially since there is another eager Challenger to Team McLaren this year, and its attack on the Can-Am establishment has been turbocharged since the very start of the year.

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