The McLaren M20 was a
sports prototype
A sports prototype, sometimes referred to as simply a prototype, is a type of race car that is used in the highest-level categories of sports car racing. These purpose-built racing cars, unlike street-legal and production-based racing cars, are n ...
developed by
McLaren for the
1972 season of the
Canadian-American Challenge Cup
The Canadian-American Challenge Cup, or Can-Am, was an Sports Car Club of America, SCCA/Canadian Auto Sport Clubs, CASC sports car racing series from 1966 to 1987.
History
Can-Am started out as a race series for group 7 sports racers with two r ...
. It served as a replacement for the team's
M8Fs, but it later became the final Can-Am design created by McLaren before the team left the series after failing to secure the 1972 championship title.
M20s continued to be entered by
private teams until the Can-Am championship was canceled at the conclusion of the
1974 season. McLaren driver
Denny Hulme
Denis Clive Hulme (18 June 1936 – 4 October 1992), commonly known as Denny Hulme, was a New Zealand racing driver who won the Formula One World Drivers' Championship for the Brabham team. Between his debut at Monaco in 1965 and his f ...
won two races during the 1972 season while Scooter Patrick won a single event in 1974 with a privately entered M20.
Development
When McLaren designed their replacement for 1971's
M8Fs, one of the team's primary goals was to improve the cooling structure of the cars in order to allow their racing drivers,
Denny Hulme
Denis Clive Hulme (18 June 1936 – 4 October 1992), commonly known as Denny Hulme, was a New Zealand racing driver who won the Formula One World Drivers' Championship for the Brabham team. Between his debut at Monaco in 1965 and his f ...
and
Peter Revson
Peter Jeffrey Revson (February 27, 1939 – March 22, 1974) was an American race car driver and heir to the Revlon cosmetics fortune. He was a two-time Formula One race winner and had success at the Indianapolis 500.
Background
Peter Revson w ...
, more comfort during races. The M8F, as with previous McLaren sports cars, featured a large
radiator mounted in the nose of the car, through which air was drawn from openings in the nose, and exited upwards over the open cockpit. McLaren designers Gordon Coppuck and Tyler Alexander devised a solution to this heat problem by using two radiators, one each mounted on either side of the cockpit, and drawing air from the side of the bodywork. This meant that hot air exiting the radiator no longer passed over the cockpit, and decreased fatigue on the drivers.
With a radiator no longer housed in the nose of the car, McLaren designs were free to redesign the nose for better
aerodynamic efficiency. This resulted in the addition of an adjustable
airfoil between the front wheel fenders which increased the
downforce
Downforce is a downwards lift force created by the aerodynamic features of a vehicle. If the vehicle is a car, the purpose of downforce is to allow the car to travel faster by increasing the vertical force on the tires, thus creating more grip ...
on the front end of the car, leading to increased grip while cornering. The new radiator design also required a redesign of the
fuel tank
A fuel tank (also called a petrol tank or gas tank) is a safe container for flammable fluids. Though any storage tank for fuel may be so called, the term is typically applied to part of an engine system in which the fuel is stored and propelle ...
s within the car. The new tanks for the M20 were compacted around the cockpit and designed to flow from the outward tanks into the central tank so that as fuel was burned off during the race,
it would not affect the
weight distribution
Weight distribution is the apportioning of weight within a vehicle, especially cars, airplanes, and trains. Typically, it is written in the form ''x''/''y'', where ''x'' is the percentage of weight in the front, and ''y'' is the percentage in the ...
of the car.
The engine of the M20 was once again a
Chevrolet V8 engine
A V8 engine is an eight-cylinder piston engine in which two banks of four cylinders share a common crankshaft and are arranged in a V configuration.
The first V8 engine was produced by the French Antoinette company in 1904, developed and u ...
, increased in
displacement
Displacement may refer to:
Physical sciences
Mathematics and Physics
* Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...
to and producing approximately 750
horsepower
Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are t ...
.
Attached to the engine was a
Hewland
Hewland is a British engineering company, founded in 1957 by Mike Hewland, which specialises in racing-car gearboxes. Hewland currently employ 130 people at their Maidenhead facility and have diversified into a variety of markets being particul ...
Mk II gearbox, mounted behind the engine rather than between the engine and cockpit as competitors
Porsche and
Alfa Romeo
Alfa Romeo Automobiles S.p.A. () is an Italian luxury car manufacturer and a subsidiary of Stellantis. The company was founded on 24 June 1910, in Milan, Italy. "Alfa" is an acronym of its founding name, "Anonima Lombarda Fabbrica Automobili." "A ...
used. The
fiberglass
Fiberglass (American English) or fibreglass ( Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass clo ...
bodywork attached to the
aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...
chassis was similar to the M8F, maintaining the "
Coke bottle
Coca-Cola, or Coke, is a carbonated soft drink manufactured by the Coca-Cola Company. Originally marketed as a temperance drink and intended as a patent medicine, it was invented in the late 19th century by John Stith Pemberton in Atlant ...
" design,
but with the addition of ducting on the side to feed the radiators.
Brakes were developed in conjunction with
Lockheed. Improving on the recently developed cross-drilled brakes from the previous season, grooves were machined into the discs to prevent outgassing.
Goodyear remained as the team's official tire supplier.
In total, three M20s were built by McLaren in 1972.
Unlike previous McLarens, no customer variants were developed for
private teams prior to McLaren leaving the Can-Am series, although all three cars were eventually sold to other teams.
Racing history
Two new McLaren M20s made their debut at
Mosport Park
Canadian Tire Motorsport Park (formerly Mosport Park and Mosport International Raceway) is a multi- track motorsport venue located north of Bowmanville, in Ontario, Canada, east of Toronto. The facility features a , 10-turn road course; a ad ...
, the inaugural round of the 1972 season. The #5 entry of
Denny Hulme
Denis Clive Hulme (18 June 1936 – 4 October 1992), commonly known as Denny Hulme, was a New Zealand racing driver who won the Formula One World Drivers' Championship for the Brabham team. Between his debut at Monaco in 1965 and his f ...
was able to achieve victory after some tire difficulties, beating
Porsche's brand new
turbocharged 917/10. Further problems appeared at
Road Atlanta
Road Atlanta (known for sponsorship reasons as Michelin Raceway Road Atlanta) is a road course located just north of Braselton, Georgia, United States. The facility is utilized for a wide variety of events, including professional and amateur spo ...
, where aerodynamics led to Hulme's car becoming airborne and flipping while following closely behind one of the Porsches. Although Hulme's car was destroyed and had to be replaced by the third M20, Denny was quickly able to recover and earned his second victory of the season at
Watkins Glen International
Watkins Glen International, nicknamed "The Glen", is an automobile race track located in the town of Dix just southwest of the village of Watkins Glen, New York, at the southern tip of Seneca Lake. It was long known around the world as the hom ...
, followed immediately by Revson in the other McLaren. Porsche earned their second victory in the next round at Mid-Ohio, aided by rain on race day.
After maintaining a close battle with Porsche in the first four races, McLaren saw the rest of the 1972 championship hopes slip away as numerous mechanical problems, mostly related to their
Chevrolet motors, left them unable to finish several events. Hulme earned another second-place finish at
Edmonton
Edmonton ( ) is the capital city of the Canadian province of Alberta. Edmonton is situated on the North Saskatchewan River and is the centre of the Edmonton Metropolitan Region, which is surrounded by Alberta's central region. The city ancho ...
, his car reliability was no match for that of
Penske
Penske Corporation, Inc. () is an American diversified transportation services company based in Bloomfield Township, Oakland County, Michigan. Roger Penske is the chairman of the privately held company, and Rob Kurnick is the president.
Holding ...
-
Porsche driver
George Follmer
George Follmer (born January 27, 1934) is an American former auto racing driver, and one of the most successful road racers of the 1970s. He was born in Phoenix, Arizona. His family moved to California when he was just an infant.
Career
Follme ...
. Both Team McLaren M20s retired at Road America, Donnybrook(Brainerd) and Laguna Seca. Hulme was able to secure second place over the troubled season, but earned only half the points total that Follmer amassed. Revson in the second half of the season, was only able to score a second at the series finale at Riverside. He was classified sixth in the standings. After failing to secure the Can-Am Championship for the first time since 1966, team owner
Teddy Mayer
Edward Everett Mayer (September 8, 1935 – January 30, 2009) was an American motor racing entrepreneur who was successful in several categories of racing, including Formula One and IndyCars.
Life and career
Mayer was born in Scranton, Pen ...
decided to concentrate the company on
Formula One
Formula One (also known as Formula 1 or F1) is the highest class of international racing for open-wheel single-seater formula racing cars sanctioned by the Fédération Internationale de l'Automobile (FIA). The World Drivers' Championship, ...
and
USAC IndyCars, leaving the Can-Am series behind.
[ ]
After McLaren no longer had use for the M20s, all three (including Hulme's rebuilt car) were sold to separate teams. Roy Woods Racing purchased one car for driver
David Hobbs to continue campaigning in Can-Am, while Fred Corbett (under the guise of Commander Motor Homes) purchased a car initially for
Mario Andretti
Mario Gabriele Andretti (born February 28, 1940) is an Italian-born American former racing driver. One of the most successful drivers in the history of motorsports, Andretti is one of only two drivers to have won races in Formula One, IndyCar, t ...
, who was later replaced by
John Cannon. Corbett's M20 was modified to add a turbocharger in an attempt to better match Porsche's further improved car, the
917/30. The third M20 was sold to the German Felder Racing Team for driver
Helmut Kelleners
Helmut Franz Kelleners (born 29 December 1939 in Moers) is a former race driver from Germany. He has won the Spa 24 Hours (1968 and 1970) and the 24 Hours Nürburgring (1972). From 1980 to 1981, Kelleners formed a successful partnership with Ital ...
, who used it in the European
Interserie Interserie is the name of a European-based motorsport series started in 1970 that allows for a wide variety of racing cars from various eras and series to compete with less limited rules than in other series.
Created in 1970 by German Gerhard Härl ...
championship.
Although none of the M20s were successful in 1973, the cars would once again be victorious during 1974. Roy Woods' M20 was sold to Herb Caplan's U.S. Racing for the
1974 Can-Am season, with driver Scooter Patrick. Patrick won the final race of the season at
Road America after the dominating
Shadows
A shadow is a dark area where light from a light source is blocked by an opaque object. It occupies all of the three-dimensional volume behind an object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, ...
suffered mechanical problems.
The Can-Am series would be cancelled shortly thereafter. Meanwhile, Kelleners's M20 was able to win in an Interserie event at the
Nürburgring en route to finishing second in the drivers championship.
References
{{McLaren
M20
Can-Am cars