The Canadian American Challenge Cup was co-sanctioned by the SCCA and CASC—it was a series nicknamed the “unlimited” series. Although there was a basic set of rules, the cars had to be two-seaters with bodywork covering the wheels, have doors, a windscreen, brake lights, and various safety requirements. However, there was no regulation on the car’s dimensions, minimum weight, materials used, or size of the tires. This was all open to the creativity of the designer.
The nickname “unlimited” came from the regulations allowing engines of unlimited displacement and number of cylinders, that is, unlimited horsepower. Essentially, this was the open sports racing car series and it became a hotbed of new technology and racing car design.
It took place from 1966 until 1974 with races in Canada and America. At its peak it was a 10-race series, and cars from BRM, Chaparral, Ferrari, Lola, March, McLaren, Porsche and Shadow were driven by such drivers as Amon, Donohue, Follmer, Gurney, Hill, Hulme, McLaren, Oliver, Revson, Scheckter, Siffert, Stewart and Surtees.
Although, it was partly known as the “Bruce and Denny Show” because of their five straight years of winning championships racing McLaren Can-Am cars, it started with a Lola championship and ended with complete domination by Porsche with the 917/10 and 917/30.
Today, there is a historic Can-Am group, which organizes races across the country, including some very popular Can-Am reunion events. The value of these cars today is determined largely by their provenance, whether a team car or a private car, the race history and the condition.
1970 March 707
March Cars was formed in 1969 and was to become well known for producing a variety of successful single-seater racing cars in all classes from Formula Ford up to Formula One. Founders Max Mosely, Alan Rees, Graham Coaker and Robin Herd were an ambitious and talented group. For the 1970 season, designer Herd penned the 707, destined for the Can-Am series. Herd, formerly from McLaren where he worked on the winning M6A, knew the task before him. The 707 had a large, sturdy aluminum monocoque. It was powered by the 7-liter Chevrolet V8 with fuel injection and had a sturdy Hewland gearbox. In its early shape it had a “Hammer Head” front wing and a large full-width single rear wing. March entered the 707 for the last three races of the 1970 Can-Am season with New Zealander Chris Amon to drive. At Donnybrooke, Amon qualified a strong 3rd, finishing 5th; at Laguna Seca, a 4th place; at Riverside, a fine 4th place. All felt that with some development the 707 could improve into a contender. Lucky for the other competition, March did not continue on in the Can-Am series the next season. One other car was made and sold for Helmut Kelleners to drive in the Interseries. Both cars can be seen today racing somewhere in the world, making noise, looking ferocious and going fast.
1973 Porsche 917/30
Porsche AG, of Stuttgart, Germany, had become famous for its successful lightweight racing cars of the 1950s and early 1960s. By the late 1960s Porsche was engineering some fascinating sports prototypes, eventually winning the Manufacturers World Championship in 1969, ’70 and ’71 with their 3.0-liter, 8-cylinder 908s and 5.4-liter, 12-cylinder 917Ks. When the rules changed at the end of the 1971 season, and the 5.4-liter 917K Coupe was not eligible to race in the World Championship, Porsche looked more seriously at the Group 7, the USA’s Can-Am Championship and the European Interseries. They decided to turbocharge the 5-liter, flat-12 engine and Porsche’s ultimate weapon was developed out of the 917K, 917PA and 917/10. It was a tube frame chassis with a lightweight, aerodynamic, fiberglass body with under panels bonded to it. The engine was a flat, 12-cylinder, 5.4-liter with twin turbochargers, which could produce an amazing 1,100 bhp at 7,800 rpm. It had a sturdy Porsche-built, four-speed gearbox and limited-slip differential. The 917/30 was the pinnacle of Porsche’s design and engineering excellence. Entered by Roger Penske and driven by Mark Donohue, it dominated the 1973 season, bringing Porsche the Can-Am championship. Later, it set a closed-course land speed record. Today these cars are owned by those content to retain ownership and rarely trade hands. The 917/30 is an example of a company’s engineers adapting to a set of rules, in a category where light-weight, good-handling, high-horsepower cars were flourishing.
Criteria Used For Assessing Valuations for this Guide:
- Degree of Originality
- Overall Condition, Restoration
- Technology, Design, Coachbuilder
- Production Numbers/Rarity
- Competition History
- Ownership History, Documentation
- Modern Event Eligibility
Regional Variances
The prices stated in this guide are based on U.S. values. The values of historic racing cars can vary as much as 25%-35% in other countries, depending on local market appeal, currency rates, import duties, and VAT. Most of the time, we are able to document known sales or closed escrows, as they say in real estate. When this is not possible, a logical estimate of the car’s value is given, based on its sales history and relationship to cars of its type.
The prices stated in this guide are based on U.S. values. The values of historic racing cars can vary as much as 25%-35% in other countries, depending on local market appeal, currency rates, import duties, and VAT.
LEVEL | VALUATION CATEGORIES |
|---|---|
I | The best combination of all criteria. |
II | Satisfies mid-range of criteria. |
III | In need of restoration. Meets only a few points of criteria |
