Driving McLaren's ultimate Can-Am car: the monstrous M8F

Americans put a man on the moon, but they couldn't beat the road rockets built and driven by a bunch of laid-back Kiwis. Paul Fearnley finds out what the fuss wasn't about.

Denny Hulme in his McLaren M8F-Chevrolet, He was a non-finisher due to a broken driveshaft, Mid-Ohio CanAm. (Photo by Bill Fox/Klemantaski Collection/Getty Images)

Hulme was a real force in Can-Am – pictured here for McLaren at Mid-Ohio '71

Klemantaski Collection/Getty Images

Kaboom! McLaren’s Mephistophelian M8F fires up like the Battle of Jutland. Its eight litres of Chevy Big Block then settles down to a jackhammer tick-over that thuds into your solar plexus. ‘Bofors Gun’ inlets gulp in huge gobbets of air and ‘Super Gun’ exhausts hurl them out. And in between, the fuel injection somehow copes with California-type demand. Western excess wrapped up in orange fibreglass. But that’s how Can-Am was in 1971: no maximum capacity, no minimum weight and (just) pre-Energy Crisis. A high-powered, big-money show that proved McLaren’s engineering and logistical capabilities, and put the Colnbrook-based outfit on a firm financial footing.

Worried that I will personally sear a hole in the Ozone Layer if I stay in one place for too long, I select second and ease out the surprisingly light clutch. No revs, just lots and lots of torque. Kadunk… kadunk … kadunk, kadunk, kadunk. The world’s fastest piece of Double Gloucester shunts along Donington Park‘s pitlane and onto the track.

It’s wet. Miserably so.

Denny Hulme in his McLaren M8F-Chevrolet, He was a non-finisher due to a broken driveshaft, Mid-Ohio CanAm. (Photo by Bill Fox/Klemantaski Collection/Getty Images)

Hulme was a real force in Can-Am – pictured here for McLaren at Mid-Ohio ’71

Klemantaski Collection/Getty Images

“You used to pray that it didn’t rain,” says Peter Gethin. This stocky ex-jockey was drafted into McLaren’s Can-Am squad for 1970 after the stunning death of team founder Bruce McLaren in a Goodwood testing shunt, and after clashing oil company contracts forced out Dan Gurney, Bruce’s original ‘replacement’, after three races with the team.

“The first time I saw Denny [Hulme] come past the pits at Goodwood — the ground literally shook — I wondered what I had let myself in for,” Gethin continues. “But the car [M8D] was fantastic, of course, and by the end of the test session you were asking for another 100bhp.

From the archive

“But that was in the dry. In the wet, on occasion I would simply drop the clutch at a slow corner and roll round it. That was the only way to do it. Even the slightest whiff of throttle would cause wheelspin.

“The problems in the dry were that the car was very heavy to drive and hot. That’s when I realised how tough and strong Denny was. I could keep up with him for the first 100 miles or so, but I struggled in the second 100 miles and he would gradually pull away. The worst race was at Road Atlanta in the Deep South; it was incredibly hot and humid. I was leading when I broke down near the end, and the marshals literally had to lift me out.”

Peter Revson Can-Am Laguna Seca 1971

1971 Can-Am champ Peter Revson en route to the Laguna Seca race win in the McLaren M8F

John Lamm/The Enthusiast Network via Getty Images/Getty Images

He’s right. We’re just rumbling around for photographs — simply resting your foot on the throttle in second gear is good enough for 60mph — but already the BTUs from the front-mounted radiator are wafting up through the cockpit, while the Chevy’s ‘killer’ joules are percolating nicely through the thin, reclining metal bulkhead that separates me from it. The steering is a bit bicep-curly, too — and that’s without downforce exerting its unseen hand.

A dry line is forming. Slowly. It’s wide enough for most cars, but not the M8F. It’s desperate to go, though. Keener than I am. And a lot keener than its understandably fretful owner. It’s frustrating — who wouldn’t want to gorge on the fattest power curve ever? — but on this occasion discretion wins over what little valour I have. When far more experienced pilots raised their eyebrows as I explained what I was about to do, and then advised a slight settling lift before the gentle crest on the approach to the chicane on Donington’s short circuit, I knew for sure that this car is beyond the extraordinary.

It feels lovely though. Once you have slithered your legs under a flat-bottomed dash (that reminds me of a guillotine), you’re closeted, hips hugged by one of the tub’s aluminium box-sections and the cockpit’s central stiffener, knees braced behind back of dash. You sit low — Gethin used to “disappear” — and you can just make out the wing tops for placement purposes. It suddenly seems a lot smaller than it had appeared from the outside. But that doesn’t mean to say it’s not wide. As engine sizes grew in Cam-Am — McLaren would eventually use a liner-less alloy-block 9.3-litre in qualifying — so too did tyre widths. The title-winning M6A of 1967 featured 13.5in rear boots; M8F is on 17in. Today, of course, this is hardly a plus. But again you get the feeling that if you’re ultra-smooth, this car will work with you. Not frighten you too much.

“You didn’t chuck them about,” says Gethin. “It paid to be neat and tidy. It was difficult on cold tyres — I went off on my first-ever lap in the car — and once they were up to temperature you had to look after them. You couldn’t drive them sideways; you needed to keep the air running along the length of the bodywork to get the downforce. Lose that and you were off.

“Oh, and the brakes were okay for their day, but they weren’t really up to the car’s performance. Getting it stopped could be tricky.”

He’s right, the calipers tucked away inside those McLaren four-spoker fronts are shamed by today’s Evo road machines. Like the rest of the car, the middle pedal feels great… but you do wonder.

Denny Hulme Can-Am 1971

Hulme won three Can-Am races in 1971, Revson five

ISC Images & Archives via Getty Images

Which is precisely what I will have to do as the rain intensifies and sloshes away that dry line. I have been lucky enough to drive la Porsche 917/10, the mighty 1000bhp Panzer that finally pierced McLaren’s armour in 1972, so I know what Can-Am megapower feels like — but I was keen(ish!) to sample the Chevy’s instant punch as opposed to the pause-rush of the air-cooled flat-12 turbo.

“I wasn’t shocked by it, but it was very exciting,” says long-time McLaren designer Gordon Coppuck. “I had a few runs around Goodwood with Denny in the Can-Am cars. We did a 1 min 11sec. That wasn’t a record, but it was pretty close. I knew the car’s theoretical performance, but it was revealing to feel it in the flesh.”

Coppuck had drawn up and finessed Robin Herd’s M6A design in 1967 and, when the latter left for Cosworth, worked with new recruit Jo Marquart on the first M8 iteration for 1968. Both were 33 and highly talented, but perhaps not yet ready to pen an entire car. In simplistic terms, Jo did the front end, Gordon the back.

From the archive

“It would have been a disaster if egos had got in the way,” admits Coppuck, “but we got on well together and I think the car came out okay.” He’s not wrong, M8A was a seminal machine that kicked off a four-year winning streak.

The biggest change Marquart and Coppuck made was to end the monocoque at the rear bulkhead and fully stress the engine (M6A’s V8 had sat between pontoons that extended to the rear of the car). They also went for a less flowing shape: a wedge. And, if it’s not a Can-Am oxymoron, they went conservative.

“We could have made it lighter, used a bigger engine, fitted a wing — but reliability was a prime function,” explains Coppuck.

That M8A was spot-on was proved by the success of the team’s evolutionary approach to B (hub-mounted bewinged dominator of 1969), D (1970) and F (1971). Pragmatic revamps were vital for a team concurrently designing F1, F2, F5000 and Indy cars. Even Coppuck’s hip-rad M20 that attempted to stave off Porsche in 1972 was instantly recognisable as being of the illustrious line.

It couldn’t last, of course. Nor could Can-Am in this form. But how fitting that Scooter Patrick‘s two-year-old M20 should close it out in August 1974 with an unexpected win at Elkhart Lake.

Bruce would have enjoyed that.