Model history: For four full seasons (1968 - 1971) the McLaren M8 and its derivatives had dominated the Canadian-American Challenge Cup (Can-Am). In this period victories by other teams or manufacturers were few and far between. That was set to change with the imminent arrival of the turbocharged Porsche 917/10 in 1972. Extensive rule changes for the World Sportscar Championship had limited the German manufacturer's option after 1971, so for the first time Can-Am became a top priority. Considering Porsche's vast resources and track-record had the established Can-Am teams and manufacturers justifiably worried. Defending champions McLaren assessed the situation and decided to start with a clean sheet. Designed by Gordon Coppuck and dubbed the M20, the all new Can-Am racer was ready for extensive testing in the Summer of 1972 (Can-Am was traditionally a Fall series).
Following the latest Formula 1 design trend, Coppuck moved the radiators from the nose to the 'side-pods' alongside the cockpit. Widest around the cockpit area, the monocoque, with some imagination, resembled a Coke bottle when viewed from the top. The advantages of this repackaging were numerous; the mass of the radiators was much closer to the car's centre of gravity, there was no longer a need to run hot water-pipes to the nose of the car, which greatly improved driver comfort and finally the space traditionally reserved for the radiators could now be used for aerodynamic purposes. For Coppuck the main objective was to get as much of the weight as low and as close to the car's centre of gravity as possible. The resulting handling improvements were hoped to make up for the power deficit against the Porsches. For this purpose 2 inches were added to the bell-housing, increasing the wheelbase and also moving the big-block engine forward by the same amount.
Although turbocharged versions of Chevrolet's V8 engines were under development, McLaren decided to continue with the naturally aspirated 'big block' that had served them so well during the previous four seasons. Despite its massive displacement of well over 8-litre, the all aluminium V8 was very light and very reliable. Adding turbochargers would only complicate things and weigh the cars down. In 1972 trim, the V8 produced in excess of 750 bhp while the M20 tipped the scales at just 690 kg. The aerodynamics package was a further development of the existing design with the addition of the wing mounted between its front fenders. McLaren made no secret of its presence and even accentuated it by painting it blue. The additional downforce over the front wheels was balanced out by fitting a full-width rear wing that was even larger than that of its predecessors. The radiators were fed by intakes just behind the widest part of the 'Coke bottle.' Two circular intakes in the front fenders provided cooling for the brakes.
For the new Can-Am season McLaren regular Denny Hulme was to be joined by fellow Formula 1 World Champion Jacky Stewart. Together they extensively tested the M20 in England, shattering the M8F's lap records by quite a margin. Illness prevented Stewart from taking part in the first race and his place was taken by McLaren's USAC driver Peter Revson. Hulme and Revson struggled with handling problems in the opening round at Mosport and were pipped for pole by Mark Donohue in the Penske entered, turbocharged Porsche 917/10. Mechanical problems for Donohue during the race forced him to make a pit-stop, handing the lead to Hulme. With his flat-12 engine sorted, the Porsche driver went back out and rapidly closed the gap with Hulme. Fortunately for Team McLaren, Donohue ran out of laps and Hulme recorded a debut win for the M20. There was little reason for jubilation as the worst fears about the Porsche's potential had proven to be true.
Revisions to cure the handling problems were made to the two M20s ahead of the next round at Road Atlanta. Donohue had crashed heavily in early testing and was too injured to drive. George Follmer proved more than a worthy replacement and he won the race that was close to disastrous for Team McLaren. Hulme did take pole but he suffered a massive accident in the race when his M20 flipped at high speeds. At the same spot Revson had already retired a few laps earlier with a blown engine. The team dealt with the setback remarkably well and built up a new car for Hulme in little over a week. Revson and Hulme, still with a buzzing head from his accident a fortnight earlier, placed the two M20s on the front row. Old times returned as the two McLarens crossed the line in first and second. Hulme took the race and the two works drivers were joined on the podium by Francois Cevert who drove one of the 1971 vintage McLaren M8Fs.
The Porsche's loss of form was only temporary. As the hugely powerful car was gradually dialled in, Team McLaren was more and more on the back foot. Follmer won the next two races as Hulme and Revson discovered the limits of the engine. Pushed too hard to keep up with the superior Porsche, the V8s had lost their reliability. Only Cevert managed to win another race for McLaren when Follmer ran out of fuel on the final lap. In the ninth and final race of the season, the Porsches underlined their superiority with a 45 second win over Revson. It would be the final outing for Team McLaren as they decided not to return in 1973. There simply were no resources to build a machine capable of taking on the hugely complicated and very fast Porsches. It was the end of an era that had brought five championships for the Papaya Orange machines.
All three M20s were sold to private customers at the end of the season. They were raced with a variety of engines in the European Interseries as well as Can-Am for several more seasons. They could offer little resistance against the 'Turbo Panzer'. Fittingly the final Can-Am race, at Road America in 1974, was won by a McLaren. Scooter Patrick grabbed the victory in the ex-Revson M20 ahead of one of the 1970 M8D works cars driven by John Cordts. Ironically with just three wins, McLaren's fastest Can-Am cars has gone into history as one of the company's least successful. The three cars built have survived and are today part of prominent collections.
Chassis M20-2 was allocated to Denny Hulme at the start of the 1972 season. He used it to win the opening round at Mosport before he crashed heavily at Road Atlanta. The chassis was eventually repaired and sold to the Commander Motor Homes, who fielded it together with two other McLarens in the 1973 Can-Am Challenge Cup. Powered by a twin-turbocharged 7.6 litre Chevrolet V8, it failed to impress. Late in the season Mario Andretti also drove the car but without noteworthy results. M20/2 eventually ended up in the Harrah Collection in Reno where it was restored to its early 1972 configuration. It is seen here during the 2009 Monterey Historic Races where it was displayed in the Rolex Moments in Time tent.
The final works McLaren Can-Am car built, chassis M20-3 was pressed into service at Watkins Glen after Denny Hulme crashed 'M20-2' during the previous round. Hulme scored a debut victory with the car, which would also be the team's final win. At the end of the year, the car was sold to the Felder Racing Team, who fielded the M20 for Helmut Kelleners in the Interserie championship. With little success, the team also used a turbocharged engine. Since then the car has been restored to its works specification. It is today part of the ROFGO Collection and seen here during the 2012 Goodwood Festival of Speed in the hands of Richard Attwood.
This is my favorite car of all time. Thank you for the excellent article and pictures. I was at the 72 Watkins Glen can am and it was great to see their final 1-2 finish.
McLaren M20 qualifying engine
Great feature on one of my favorite cars. However, I believe the 787 bhp engine refers to a special "big block" built for the Riverside CanAm. This was a 565 cubic inch engine with a bore and stroke of 4.50x4.44 inches. This was a special qualifying engine used by Denis Hulme. The output was quoted as 787 bhp at 6400 rpm and 740 ft/lbs at 4400 rpm. This engine was described in the book "Can-Am" written by Pete Lyons in 1995.
Canam fan 11-14-2009
I absolutely love the M20's. Perhaps my favorite car of all time but the pictures do not do it justice. Could you post some pictures of it on the racetrack.
PS The very last Mclaren 1-2 finish in the canam was at Watkins Glen in 1972 when Hulme and Revson finished ahead of (well ahead of actually) the 917/10k of Follmer. This was a big blow to Porsche as they had brought all their management and the german media to the event only to see their car get trounced. If I'm not mistaken event Francios Cevert in the year old M8F finsihed ahead of Follmer.