You know a motorsport series is going to be pretty wild if its rulebook is so short it reads like a Chinese takeaway menu, but that’s precisely what Can-Am (Canadian-American Challenge Cup) was when at its early ‘70s peak. The series existed for a few short years and ran competitively between 1966 and 1974, after which its appeal and profile were diluted by the worldwide oil crises, not to mention the increasing safety demands placed on top-tier championships.
Those few, precious seasons proved to be instrumental though, not least as they gave us, the motorsport loving public, some of the most extreme cars ever to grace a circuit, all of them within the fabled Group 7. Group 7 rules were almost non-existent, so much so that they really were an engineer’s dream.
This meant that pretty much anything you could think of was fair game and up for grabs, providing the resulting car’s wheels were enclosed and it had a pair of seats. Massive turbos and superchargers? Go right ahead. Huge capacity V8s with bellowing pipes? Step right this way, Sir! Rudimentary aero designed with only the shortest of wind tunnel sessions? Why ever not!
Can-Am burned bright and fast, and by the middle of the ‘70s the series had peaked. Not that this makes any of the cars it spawned any less incredible or worthy of the Retropower Hero treatment though, and these are 5 of our favourites.
This became the yardstick by which all Can-Am rivals were measured from the moment it broke cover at Road America in 1968, and went on to establish McLaren as one of the series’ preeminent teams. Denny Hulme and Bruce McLaren became the most successful drivers in the championship as Can-Am roared towards the 1970s, the former claiming the 1968 title at the wheel of the M8A, his team mate (and founder) a close second.
That’s not to say that there was anything especially revolutionary about the Papaya Orange cars because, in pure mechanical and design terms at least, there wasn’t. They were powered by large, 7l naturally aspirated Chevy V8s, mounted amidships and sending their power to the rear wheels by way of a Hewland 4-speed manual gearbox. This was wrapped in a wedge-shaped body typical of Can-Am racers of the time, while increasingly large wings sprouted as the season ticked by. Power output was reckoned to be approximately 630bhp in 1968, rising to 680bhp at their peak some years later.
What set the M8 and its derivatives apart was the attention to detail employed by Bruce and co in their design and construction, leading to hitherto unheard-of levels of reliability. It made it all the more tragic when Bruce McLaren was killed testing the latest M8 variant at Goodood in 1970.
Chances are that if you recognise only the one Can-Am car, it’s this one. Porsche had been a growing force in the series as the ‘60s gave way to the ‘70s, first with the capable but somewhat underpowered 908, then the 917/10 of 1972, a car which won three-quarters of that season’s races and underpinned the blossoming relationship between Stuttgart and one Mark Donohue.
This relationship reached its apex with Porsche’s final Can-Am creation, the monstrous 917/30 of late 1972. The striking looking machine tipped the scales at a mere 815kg, while power came from the most capable variant of Porsche’s fabled commitment to ‘flat’ engines, in this case a turbocharged 5.4l running anywhere between 1.3 and 2BAR depending on spec, track or whether the lunatic at the wheel was heading out to qualify or race. Power was anywhere between 1100bhp and, a figure proven on Porsche’s own dyno, a faintly ludicrous 1500bhp.
It didn’t take long for the impact of such a powerful, expertly driven machine to be felt, and Porsche was soon the only team bothering both the top of the time sheets and the podium. The 1973 season was a walkover for the pairing of Donohue and big-boost, aero-honed 917, and the combination won 6 of the 8 races on its way to the title.
Never one to shy away from a challenge (even one with a certain degree of mortal peril thrown in), Donohue then took the 917/30 on a closed course world speed record attempt, averaging 221mph at Talladega Speedway…and nudging 241mph on the straights.
Seldom has a race car looked more like something you’d see sitting forlornly, steadily yellowing outside of a down-at-heel branch of Curry’s, but that’s what the Chaparral 2J brought to mind, at least when viewed from behind. Looks were never part of Jim Hall’s equation when he penned the 2J, however, with his focus instead being on the then black art of ground effect technology and how best to use it within a race car.
Group 7 provided the only rulebook open-ended enough in concept for Hall to be able to truly test his theory, and the 2J of 1970 was perhaps the most extreme example of just what was possible with enough gumption and the ability to think outside the box. Some elements were conventional: power came from an all alloy Chevy ZL1 ‘big block’, an engine powering a good portion of the grid by this point and good for an easy 650bhp when paired with a three-speed semi-automatic transaxle.
Things became rather less conventional when the 2J was viewed from the rear, whereupon its trump card was revealed in all its functional, white goods glory – the Rockwell two-stroke snowmobile engine and associated drive assembly, including a pair of fans taken from a Howitzer! These were paired with a Lexan skirt running around three-quarters of the bottom of the 2J, which meant that, when running correctly on smooth tarmac, the car generated an area of low pressure beneath it and the track.
As anyone who’s read about Gordon Murray’s Brabham ‘Fan Car’ (a machine which debuted nearly a decade later) will be able to tell you, the impact of the cushion of trapped air was dramatic, with the 2J (now nicknamed ‘the Sucker Car’) able to corner at hitherto unheard of speeds and pull an 1.5G in certain, high speed bends.
As you might expect given the technology involved and the materials available at the time, the 2J suffered from patchy reliability, much of it centred around getting the suspension-linked skirts to function correctly. It was also less than popular with those charged with chasing and attempting to pass it, mainly as when functioning as intended the fans tended to suck up any and all track based detritus, before firing it at the chasing pack at high speed!
Rectifying the myriad issues nearly drove Hall and the team to desperation, no more so than at Laguna Seca when, having smashed the 1969 lap record by a massive margin, before a blown engine wrecked their chances on race day. The clear potential of the car caused Chaparral’s rivals to join together in protesting it and were eventually successful, with ‘moveable aerodynamic devices’ banned from the following year.
Lola T70 Mk2
The prettiest Sportscar racer ever, so much so that it makes the likes of the Ford GT40 look akin to an Austin Maxi? Well, I think this to be the case and will gladly fight anyone who feels differently, but there’s no doubt about the T70’s Can-Am performances in the late ‘60s, before it was simply overwhelmed and out-gunned by the larger capacity opposition.
The highpoint for the plucky British concern was undoubtedly 1966, Can-Am’s first ever season and one in which John Surtees, a certified F1 great by this point, took a trio of victories to take the title in fine style.
The banning of forced induction and the imposition of fuel flow restrictions at the end of the 1973 season effectively rendered the monstrous 917/30 uncompetitive, and as such there was room for a new challenger built around a differing concept, the Shadow DN4A. Shadow’s Don Nichols had already set paddock tongues wagging with his previous creation, the ‘tiny tyres’ AVS Shadow Mk1, but the car struggled with a lack of brake potency in an era when stopping power largely equated with disc size.
The DN4 was rather more conventional but much, much more competitive. Penned by F1 designer Tony Southgate and powered by a big, NA Chevy V8, the DN4 proved to be the dominant force in Can-Am that season, taking up where the Porsches had left off and wiping the floor with the opposition that remained. Shadows took a one-two in the title race, with Jackie Oliver the man sitting pretty at the end of the season.
Bonus – Mac’s It Special
Motorsport isn’t exactly short of examples of ideas which were superb in principle, yet lost something (all too often, everything) in the jump from the drawing board to the pit garage, and the Mac’s It Special was one just car. Radically different in concept to anything else on the grid at the time (and pretty much since), the Mac’s It eschewed the usual, big block Chevy route to forward propulsion in favour of a quartet of Rotax L2C bike engines, one at each wheel.
The four two-stroke motors gave a combined displacement of 3.1l and were expected to provide competitive power with less of a weight penalty and improved weight distribution. Of course getting four different engines to work in harmony proved to be a taxing undertaking, so much so that shattered drive-shafts soon became the Mac’s It’s calling card. It was raced just the once at Laguna Seca in 1970, and while interesting and doubtless impressive it was also unreliable, slow.