Guide: Ford P68 (F3L)
Background
One day after the 1967 Le Mans 24 Hours had seen all previous records broken, the FIA announced a three-litre engine limit would be imposed on Group 6 Prototypes from 1968.
Top flight Prototypes had become so fast that the governing body felt drastic action was needed to rein them in. However, the decision was made without any manufacturer consultation and came as a massive shock.
Cars with up to five-litre engines could still race, but now only in the Group 4 Sports car category where 50 units were required to secure homologation.
As Enzo Ferrari considered the new three-litre engine limit for Group 6 Prototypes to blatantly favour Porsche, he withdrew his team from the 1968 World Championship to go Can-Am racing instead.
Like Ferrari’s Group 6 P cars, Ford’s Mk4 was also made obsolete by the new 1968 regulations. This seven-litre Prototype had been created specially for Le Mans; with nowhere to run, Ford officially withdrew from sports car racing. After back-to-back Le Mans wins in 1966 and 1967, they had already achieved their target of beating Ferrari anyway.
By this time, the Ford Advanced Vehicles factory that had been set up in Slough to design and build GT40s had long since been handed over to John Wyer Automotive Engineering (JWAE).
Unlike the big seven-litre Mk2 and Mk4 GT40s, the standard 4.7-litre Mk1 GT40 had already been homologated into the Group 4 Sports class. With an up to two-litre advantage over Group 6 cars, John Wyer reasoned the well-proven platform stood a good chance of outright victory at certain high speed tracks. Backed by Gulf Oil, JWAE successfully fielded blue and orange GT40s equipped with all the bells and whistles throughout 1968.
Meanwhile, although the parent firm had decided to withdraw from Prototype racing altogether, Ford UK still wanted to compete in the 1968 Prototype class.
Ford UK had already bankrolled development of the Cosworth DFV which was arguably the best three-litre engine around. They understandably reasoned that, if installed in a suitable chassis, a DFV-powered Group 6 Prototype could be a world-beater.
The project to create such a machine was outsourced to Alan Mann Racing (AMR).
Based in Byfleet, Surrey, AMR had been a factory-backed Ford satellite team since 1964.
In 1966, Ford had asked AMR to develop a lightweight version of the seven-litre GT40. The team had also achieved considerable success with Fords in touring cars and GT racing.
No expense was spared for the new P68 Group 6 challenger (which was also sometimes dubbed the F3L).
As part of the arrangement, Ford UK paid for a driver roster that included some of the best talent in the business.
Chassis
The P68 was designed in AMR’s workshop by Len Bailey who had played a key role in both the GT40 and Mirage M1 programmes.
The P68 was essentially a two-seat Formula 1 car with fully enveloped body draped over an aluminium monocoque. Although the Cosworth DFV was originally designed to act as a stressed member, Bailey designed the P68 to carry the engine in a traditional subframe.
Independent suspension followed period F1 practice with double wishbones at the front and single top links, inverted lower wishbones and two radius rods at the rear. Coil spring / damper units were fitted at each corner along with anti-roll bars at either end.
11.5-inch disc brakes were supplied by Girling. They were carried inboard of the cast magnesium uprights for more effective cooling.
The light alloy centre-lock wheels had a 15-inch diameter and were shod with Goodyear tyres. 8 and 9-inch wide rims were available for the front with 14s and 15s for the back.
Engine / Gearbox
In the engine bay was Cosworth’s three-litre DFV which had proven a revelation since its introduction at the Dutch Grand Prix in June 1967.
The DFV was initially used exclusively by Lotus for their Type 49. In the hands of Jim Clark and Graham Hill, the Cosworth-powered Lotus took pole position at all nine of the remaining races that season.
Although the DFV was ideal for circa 90-minute races like those in Formula 1, its designers, Keith Duckworth and Mike Costin, were never enthusiastic about an endurance racing version and questioned the engine’s durability.
The DFV was also renowned for creating major vibrations, but as Ford UK were funding both the P68 and DFV programmes, Duckworth and Costin had little choice but to supply the motors.
A dry-sumped all-alloy 90° V8 with dual overhead camshafts and four valves per cylinder, the DFV displaced 2993cc thanks to a bore and stroke of 86.7mm and 64.8mm respectively.
Compression was 11.5:1 and the fuel-injection system was supplied by Lucas.
Peak output was 420bhp at 9000rpm and 270lb-ft at 7000rpm.
Whereas Lotus used a five-speed ZF 5DS gearbox in 1968, AMR coupled the P68 engine to a Hewland DG300.
Bodywork
The bodywork was designed to produce the lowest possible drag coefficient. It was refined at Imperial College London’s wind tunnel during the latter part of 1967.
The shape emerged long, low and curvaceous.
Skinned in lightweight aluminium, there was initially a notable absence of downforce-inducing addenda.
The primary nose intake fed air to the radiator while smaller ducts either side were for the brakes. The headlights and indicators were mounted under clear Plexiglas covers (a full complement of lighting was required by Group 6 regulations).
Also mandatory was a spare wheel (mounted above the gearbox) plus space for a passenger seat and luggage (the famous FIA suitcase).
Access to the cockpit was via a pair of gullwing doors.
Interior
The rudimentary crackle black dash was home to a variety of instruments plus myriad flick switches and an exposed fusebox.
Either side of the dash were ventilation outlets to help cool the cockpit as the Plexiglas side windows were fixed in position.
Aside from a bucket seat and some additional padding for the driver’s thigh (which rubbed against the right-hand side gear mechanism), there was no upholstery, just acres of riveted aluminium panelling.
Weight / Performance
The first P68 weighed in at 670kg which was 20kg over the Group 6 class minimum.
Top speed was a predicted 217mph.
Launch & Development
The bright red P68 was unveiled by Ford’s European head, Walter Hayes, at the Hilton Hotel in London during March 1968.
Throughout shakedown tests at Goodwood, the team’s number one driver, Frank Gardner, found chassis 01 too cramped. To solve the problem, AMR built chassis 02 with a 1.5-inch longer wheelbase in time for the first race of the year (the Brands Hatch 6 Hours on April 7th).
John Surtees and Jack Brabham also took the wheel of 01 pre-season, but refused to race the unstable machine.
1968 Brands Hatch 6 Hours
Alan Mann had hoped Lotus drivers Jim Clark and Graham Hill would pilot 01 for its debut race. However, Lotus kept them to an already agreed Formula 2 date at Hockenheim; an event that would claim Jim Clark’s life.
Mike Spence and Jochen Rindt were therefore asked to drive chassis 01 while chassis 02 was entered for Denny Hulme and Bruce McLaren.
The P68s didn’t arrive at Brands until late on Friday afternoon, by which time practice was already well underway.
As the tail section for chassis 02 still hadn’t been finished, McLaren initially lapped without it. Unfortunately, the bodywork from 01 couldn’t be used as it didn’t fit the new long wheelbase car.
On Saturday, both P68s were out on track, but ran very hot. It turned out the engine subframe not only added weight and complexity, it stopped the engine from cooling properly.
Neither car looked particularly well sorted, however, McLaren eventually got his time down low enough for second on the grid alongside the pole-starting Jo Siffert / Hans Herrmann Porsche 907.
In third and fourth were two more of the works 907s.
Spence set fifth fastest time in chassis 01, but when he returned to the paddock after the final session, AMR found the engine had severely overheated and was not in a raceable state.
Alan Mann had to withdraw the car and decided to put his two fastest drivers (McLaren and Spence) in chassis 02. Rindt and Hulme were sent home.
When the race started, McLaren initially nosed ahead until he missed second gear and was engulfed by half the field. He was back up to fifth by lap two and on lap three flew past the Gulf GT40 of Jacky Ickx. At this point, he set about hunting down the trio of lead Porsches.
Third place Gerhard Mitter was soon dispatched. By lap eleven, McLaren had dealt conclusively with Vic Elford for second.
As the leaders caught the backmarkers, McLaren went passed Siffert to head the field.
By lap 20, the New Zealander had a 2.5 second advantage, but on lap 33, he was back down to third after getting blocked by a slower car.
McLaren then re-took the lead on lap 42. On lap 53, he swept into the pits to hand over to Spence.
Unfortunately, a four minute stop for fuel and front tyres dropped the P68 well down the order. By contrast, the Porsche team typically only took a couple of minutes per stop.
Spence pressed on until lap 66, when the P68’s driveshaft failed and it coasted onto the grass. The car’s promising debut had come to an end barely two hours into the race.
Death of Mike Spence
Exactly one month later, Mike Spence was killed while testing a Lotus for the Indianapolis 500.
1968 Nurburgring 1000km
The P68’s next appearance came at the Nurburgring where two cars were entered for the 1000km race on May 19th.
The only technical change was larger GT40-spec. rotoflex driveshaft couplings after the failure at Brands Hatch.
For this race, Frank Gardner and Richard Attwood were paired in the long wheelbase car (02) while the original short wheelbase example (01) was allocated to Chris Irwin and Pedro Rodriguez.
Friday practice was held in damp conditions. Chris Irwin went out and set a blisteringly quick time on his second lap. However, on his third, the P68 got airborne going over the bump at Flugplatz.
The car rolled end-over-end at high speed and finished upside down in a ditch with the engine still running.
The marshals were afraid to go near the fuel-soaked car in case it caught fire; it was left to fellow drivers Jean Guichet and Rico Steinemann to extract Irwin who had been critically injured.
Guichet and Steinemann bravely turned the ignition off and got the semi-conscious driver out.
Irwin was sent to hospital and while he did eventually recover, his racing career was over.
01 was severely damaged and never raced again. Apparently, with its links to Jim Clark, Mike Spence and Chris Irwin, Alan Mann felt the car was cursed and instructed Len Bailey to scrap it.
For the Saturday practice session in Germany, chassis 02 was switched to Koni dampers which allowed more flexibility of adjustment. Attwood went on to set a time good enough for fifth on the grid behind a works 907, a Gulf GT40, a works Porsche 908 and a factory Alfa Romeo Tipo 33/2.
By race day, the track was virtually dry and proceedings got underway with a traditional Le Mans start.
Attwood was delayed by a problem with his seatbelts and slid sideways off the grid as he tried to avoid a GT40 pulling away at the same moment.
After a single lap, he came into the pits already well behind; the car’s front brake pads had dropped out! A change took over six minutes.
On the fourth lap, Attwood was back in again. This time, the AMR crew changed a punctured rear tyre and refitted one of the doors which had badly buckled after flying open.
Attwood rejoined, but was soon out of the race for good when he stopped at Bergwick with a broken ignition transistor.
The final ignominy of a difficult weekend saw 02 side swiped by an Alfa Romeo just as Attwood was about to get out.
1968 Spa 1000km
Chassis 02’s bodywork was repaired in time to attend the Spa 1000km a week later.
Now the sole P68 after Chris Irwin’s horror crash at the Nurburgring, 02 was entered for Frank Gardner and Hubert Hahne as Richard Attwood was racing for BRM at the Monaco Grand Prix.
Three days of practice were scheduled on the 14km circuit.
On day two, Gardner set a shattering pace that no-one got close to. The P68 wasn’t seen again until the race.
Gardner ended up four seconds faster than the Gulf GT40 of Jacky Ickx / Brian Redman. Third on the grid was the Ecurie Francorchamps GT40 of Spa specialist, Willy Mairesse, and Jean Blaton.
It seemed the P68’s low drag design was perfectly suited to the fast Spa circuit which bode well.
However, race day was exceptionally wet and the track was drenched negating AMR’s performance advantage.
Ickx made a superb start in the Gulf GT40. At the end of the first lap, he had established a 30 second lead.
Meanwhile, Gardner dropped down to seventh in the P68. At the end of lap one, he came into the pits with a badly misfiring engine. After a while spent scratching their heads, the AMR mechanics pushed the car back into its transporter; water had poured through every conceivable vent and drenched the Cosworth engine.
1968 Oulton Park Tourist Trophy
The P68’s next two outings were part of the British Sportscar Championship.
First was the Oulton Park Tourist Trophy on June 3rd. The P68 was the only three-litre Group 6 Prototype to attend the 110 lap three hour race.
Richard Attwood was back behind the wheel of chassis 02 and took pole position with a time four tenths of a second faster than Jo Bonnier’s Lola T70 MK3 GT. Back in third was David Piper’s Ferrari 412 P.
Attwood made a great start. By the end of lap one, he had established an impressive lead which he continued to build upon.
Then, on the tenth lap, the P68 came in for an unscheduled stop. The AMR mechanics made a couple of adjustments to the rear. Attwood went out for one more lap, only to then come straight back in. The differential had failed.
Richard Attwood was able to switch cars during the race and co-drove David Piper’s 412 P to second place overall. Victory went to Denny Hulme in the Sid Taylor Racing Lola T70 Mk3 GT.
1968 Martini Trophy, Silverstone
At the Silverstone Martini Trophy in late July, AMR reported that a new P68 (chassis 03) would be ready for the Zeltweg 500km World Championship race in late August.
The team arrived at Silverstone in good spirits with several hundred test miles completed at Goodwood since the Oulton Park TT. New parts fitted to chassis 02 included a reworked brake system with ventilated discs.
Frank Gardner was brought in to drive the 300km race. He was pipped to pole by Denny Hulme’s Lola T70 Mk3 GT. Mike De Udy was third driving a similar Lola to Hulme (one of four in the race).
Gardner made a tremendous start to take the lead. At the end of the opening lap, the positions were Gardner, Hulme and De Udy.
By lap six, the lead pair had already lapped half a dozen cars. By lap 19 they had gone passed the entire field.
Such was their astonishing speed, they repeated this feat on lap 33.
On lap 35, Gardner opened up 15 second lead when Hulme span. With 30 laps to go, it looked like the P68 might take its maiden win (and finish its first race).
However, disaster struck just seven laps later when the oil pressure zeroed again. Gardner knew the engine was toast and coasted to a halt at Becketts.
A new lap record was little consolation.
Plans for 1969 & the P69 Open Sport
In mid September, Alan Mann announced the team intended to continue with the P68’s development; three new chassis were to be built for 1969.
They would run alongside a brand new Len Bailey-designed DFV-powered Spyder, the P69 Open Sport.
With AMR no doubt distracted by the P69 Open Sport (which was also being funded by Ford UK), just one new P68 was actually ready for 1969 (chassis 03). This was the example AMR had expected to have ready by August 1968.
No fundamental changes were made, just the addition of bigger brakes and large rear suspension-mounted aerofoil.
Both the P68 and P69 were scheduled to race at Brands Hatch on April 13th 1969.
Six weeks before they appeared, Porsche launched a new model that shifted the landscape.
To stimulate entries into the poorly attended Group 4 Sport class (where five-litre engines were permitted), the FIA slashed production requirements from 50 to 25 units. Easily capable of building 25 suitable cars, Porsche created the 917, an out-and-out prototype with a 2000cc advantage over the rest of the field.
1969 Brands Hatch 6 Hours
The Brands Hatch 6 Hours was held the week after Porsche were granted homologation for the 917.
Denny Hulme and Masten Gregory were brought in to drive the P68 while the P69 Open Sports was allocated to Jack Brabham and Frank Gardner.
Things did not get off to a good start.
The P69 Open Sports proved a handful in early practice and then the engine ran its bearings. It would need to go back to Cosworth for a rebuild.
AMR owned four of the sought after DFVs: one was away being rebuilt, one had been lent to Lotus for the South African Grand Prix and one was in each of the P68 and P69. Given its handling problems, AMR decided to withdraw the P69 rather than try and switch powerplants.
As he had done a year earlier, Alan Mann sent two of his drivers home early from Brands Hatch. This time Brabham and Gregory were dropped in favour of Hulme and Gardner.
The P68 started from seventh on the grid behind four works Porsche 908s, the solitary Scuderia Ferrari 312 P and Scuderia Filipinetti’s Lola T70 Mk3B GT.
By the end of the opening lap, Hulme had risen to sixth.
Despite the car’s enormous new aerofoil flapping around alarmingly, he was soon closing in on the fourth-placed Porsche.
With less than half an hour gone though, the P68’s race ended prematurely once again. The engine had terminally lost oil pressure. Once Hulme had coasted into the pits, the car was wheeled away.
1969 Martini Trophy, Silverstone
AMR’s next appearance with the P68 came at the Silverstone Martini Trophy on May 17th 1969.
Chassis 03 arrived in the same specification as it had appeared at Brands Hatch, but with another freshly rebuilt engine.
Frank Gardner was brought in to drive the 300km event (round five of the 1969 British Sportscar Championship). His fastest practice time was six tenths faster than his lap record from 1968 and 1.9 seconds faster than Brian Redman who started second on the grid with a Lola T70 Mk3B GT.
Race day dawned wet, so the AMR crew decided to remove chassis 03’s spoiler as speeds were anticipated to be much lower.
The race started with a few exploratory laps behind the pace car as rain teemed onto an already waterlogged track.
Unfortunately, the P68 pulled into the pits with drowned electrics and never started the race.
Ford UK Pulls Out
After one disappointing result too many, Ford UK pulled out of the project.
The P68 and P69 clearly required much more development, but even with a dramatic uptick in reliability, thanks to the arrival of the Porsche 917, the writing was on the wall for three-litre Group 6 Prototypes.
Ford UK retained the two existing P68s until the 1970s.
Around this time, the tired looking ex-display machines were sold to Tom Wheatcroft of the Donington Collection.
The car that was almost destroyed in Chris Irwin’s crash at the Nurburgring in 1968 (chassis 01) was reputedly never scrapped by Len Bailey…
Text copyright: Supercar Nostalgia
Photo copyright: Ford - https://www.ford.com
