7th Having finalised their race settings, Team Lotus and engine partner Ford turn their attention to qualifying, when 30 per cent nitromethane will be used. A tyre decision must also be made before Pole Day: Goodyears are 2-3mph faster but have a tendency to chunk; thus Clark demands Firestones.

8th At 158.926mph, he closes on the lap record.

9th Parnelli Jones’ Type 34 also suffers a hub failure and all Lotuses and Lolas are grounded.

10th Foyt (on Goodyears) laps at 158.311mph; Clark manages 157.168mph.

11th Foyt is quickest again – 159.943mph – but says his Lotus is “unsanitised” compared to his Lola. Mind games. Clark laps at 157.8mph.

12th It’s confirmed that Team Lotus will not contest the Monaco GP (May 30). Talk of a Ford jet whisking Clark from Nice to Indy was merely that: talk. Foyt is fastest: 161.146mph; Clark – clocked at 196mph on the back straight and 149mph through Turn Two – laps at 160.142mph.

15th A 200,000 crowd enjoys a thrilling Pole Day. Its running order is decided by ballot for the first time: Clark draws 12. After a late swap of gear ratio, he joins the track moments after rookie Mario Andretti has set a four-lap record in his Hawk-Ford: 158.849mph. Clark, also on Firestones, tops that: 160.729mph. He’s being interviewed when Foyt’s opening lap is announced: 161.958mph. ‘Super Tex’ takes pole – at 161.233mph – before Gurney completes an all-Lotus front row. His place in the race secure, Clark returns to Scotland for a much-needed break. Incessant Indy hoopla is not to his taste.

27th Final checks on Carburetion Day: back on pure methanol, all goes well.

30th Team Lotus’s mechanics finish their final preparations unusually early: 10.30pm.

31st Clark assumes the lead of the 500 at the start when Foyt misses his shift. The latter, reportedly running nitro, takes the lead on the next lap; Clark makes it easy for him, as he plans to follow and assess. But Foyt’s Goodyears seem to have shed some speed in curing their chunking and Clark realises that he can lap faster, without exceeding his 8800rpm limit.

He repasses on lap three – and leads a total of 190 laps. His supremacy is absolute.

His mandatory refuelling stops, on laps 66 and 136 – using designer Len Terry’s twin-pipe venturi rig and carried out by crack NASCAR crew the Wood Brothers – are paragons of efficiency. When Foyt’s transmission fails after 115 laps, Clark’s only worries are a strange noise from the rear and a slight soreness in his right wrist.

He wins – the first overseas victor since 1916 – by two minutes, having broken 19 of 20 distance records and averaged 150.633mph for 3hr 19min 05sec. His purse is $166,621, which he shares in usual Lotus fashion: 45 per cent each for himself and the team and the remainder for the mechanics. He also wins free meat for a year (he takes cash in lieu), an engraved Premier watch and a $1000 man’s wardrobe, plus the Plymouth Sport Fury convertible Pace Car. (Ford eventually swaps the latter for a Galaxie 500 after the replacement Mustang earmarked for Clark is accidentally dropped onto the dock at Southampton.) The team celebrates in a local Italian restaurant. Because Memorial Day is ‘dry’ in Indiana, red wine is served in coffee cups.

June

4th Clark qualifies fourth for the Player’s 200 at Mosport in the works Type 30 Series 2.

5th His race ends because of a broken driveshaft in the first 100-mile heat.

7th After another transatlantic flit, he loses his rag when a rival baulks his Cortina, fitted with new BRM rods and pistons, during the short morning practice at the Whit Monday Crystal Palace meeting. He regains his composure to qualify second (behind Gardner’s Cortina) for the Norbury Trophy, and wins his class by finishing second overall to Roy Pierpoint’s Mustang. He also qualifies second for the F2 London Trophy, but wins both 25-lap heats in a Type 35-Cosworth. The latter result earns him £150.

11th The first two-hour practice session (for works teams only) at Spa’s Belgian GP is complicated by a leaking oil pipe that sidelines his four-valve Type 33 and forces Clark into team-mate Mike Spence’s 16-valve flat-crank car. He’s fourth-fastest nevertheless.

12th More frustration. Team Lotus is swapping from peg location to knock-off hubs and track time is lost because of ill-fitting wheels. Back in chassis R11, Clark digs deep to qualify second, albeit 2sec slower than Hill’s BRM.

13th Rain. Hill gets the jump, but Clark passes him despite the spray and holds a big lead after one lap. “Lifting off less than the others,” he laps all bar Stewart’s BRM and wins by 44.8sec, despite a bout of clutch-slip towards the end.

15th Ford GB invites Clark, Stewart and Whitmore to a PR stunt at Brands: driving a D300 truck loaded with one ton of concrete blocks. Clark sets fastest time on the short circuit before bald tyres end the fun.

17th Indy winners Clark, Chapman and Type 38 are the star attractions in Ford’s Product Salon at the World’s Fair in New York. Clark commits a PR gaffe by slating “lousy” Le Mans before remembering how much money his host is spending trying to win that weekend’s race.

24th Clark, Stokes, Chapman and Spence fly to Clermont-Ferrand for the French GP. On arrival, they bump into Yuri Gagarin, who has jetted from the Paris Air Show at Le Bourget. The Russian cosmonaut is a fan of Clark’s and jollity ensues. Thus delayed and dashing to the hotel, Chapman crashes the hire car into a ditch. Clark is knocked unconscious momentarily. The incident is kept secret and the injuries are treated at a doctor’s surgery gone midnight.

25th Clark thumbs a lift from Surtees after the Type 33’s rear suspension fails during the first two-hour practice session. Fifth, he’s the fastest newcomer to this challenging five-mile circuit.

26th Matters go from bad to worse when the four-valve engine snaps a camshaft as Clark begins his pole bid. Jumping into the spare car – chassis R6, fitted with an old high-exhaust V8 – he grabs pole from Stewart by five-tenths.

27th “A typical Clark race,” according to Chapman. Still in R6, he leads all 40 laps, sets a new lap record, wins by 26.3sec – and collects £660. Had it not been for Stewart, his nearest challenger would have been two-and-a-half minutes distant.

July

3rd America’s IRS is withholding half of Clark Indy winnings, the Daily Express reveals. An appeal is under way. In the meantime, he qualifies third for the F2 Reims GP.

4th A typical Reims slipstreamer, the top four separated by six tenths after 191 hectic miles. Clark’s Type 35 finishes third behind Jochen Rindt’s Brabham and the Lola-BRM of Gardner; he reckons that he has been “duffed up” by the opposition.

5th He flies to Zurich for a lunch meeting with Ford bigwigs…

6th …and then flies to Paris and drives to Rouen…

7th …where he practises for the F2 race before returning home for the British GP.

8th Though forced by an engine shortage to use a two-valve Climax, he tops the morning practice session at Silverstone. He goes two tenths faster in the afternoon, but Hill’s BRM pips him by a tenth to the £100 on offer for the day’s fastest lap.

9th Reunited with chassis R11 and its four-valve engine, Clark is the only man to dip below 1min 31sec and so claims pole. In America, meanwhile, the cover of Time features his portrait – by Austrian-born American artist Henry Koerner – beneath the headline The Quickest Man on Wheels.

10th Clark holds a 30sec lead with 20 laps (of 80) remaining in the British GP when a crankshaft seal fails and the oil pressure dips alarmingly during surge; he has to freewheel around certain corners to save the engine. BRM alerts Hill, who begins to charge despite his spongy brakes. Though the latter sets the fastest lap on the last lap, his Lotus quarry escapes capture by 3.2sec. Clark, Chapman, Spence and Stokes dash to Luton Airport, where Chapman’s private plane is ready for the short hop to Rouen. They land as darkness descends.

11th The Brabhams of Brabham and Hill claim pole and the fastest lap respectively, but Clark’s Type 35 wins the F2 Rouen GP by 14.5sec. He decides to stay overnight to celebrate his Trophées de France title with a glass of champagne, followed by a meal with the mechanics at a local restaurant.

12th He then flies to London in “filthy weather” and spends the remainder of the day catching up on paperwork. His Daily Express column reveals that he’s thinking of retiring and denies any secret arrangements between Chapman and Ford to build a 3-litre F1 engine for the new 1966 formula.

14th Clark and Chapman receive BARC Gold Medals from athletics golden girl Mary Rand at London’s Grosvenor House Hotel.

15th “Nothing could ever induce me to leave Scotland permanently,” writes Clark in the Daily Express.

16th It’s bitterly cold at Zandvoort as Clark’s Type 33 tops the timesheet in morning practice for the Dutch GP. It rains in the afternoon.

17th Despite better conditions, any hope of his improving on that Friday lap ends when the four-valver dumps its oil. He will contest the race in Spence’s 16-valve, flat-crank car, chassis R9, and start from the middle of the front row.

18th After passing Richie Ginther’s Honda and Hill’s BRM before six laps are complete, Clark controls proceedings to win by 8sec. That he sets the race’s fastest lap as early as lap five suggests that he has speed to spare. The day ends on a sour note, however, when Chapman is arrested for punching a policeman. The prize ceremony is cancelled and Clark alters his travel plans – he’d been scheduled to judge a competition at London’s Lyceum – to act as a witness. Chapman faces a £500 fine or a two-year prison term…

19th …but is released without charge by a court in Haarlem. During his night in the cells he has sketched a new Formula 3 design on the back of the writ!

30th Any thoughts of clinching the drivers’ and constructors’ world championships at the German GP are put on hold as Clark’s Type 33 bounces and scrapes around the Nürburgring. A raised ride height and different shock absorbers cure this and he’s almost 4sec faster than his rivals in the afternoon.

31st He keeps a wary eye during the final two-hour morning session, but nobody comes close and he will start from pole.

August

1st Finding good grip on the concrete pit apron, Clark jumps into a lead that he’s never to relinquish. His standing lap is a lap record, and he lowers the mark again on laps two and three. Though Hill’s BRM matches him on the latter, Clark pulls away at a rate of three seconds per lap thereafter. Having set fastest lap on lap 10 – at more than 101mph – he senses a change of engine note and backs off, yet wins by 15.9sec. He’s thus world champion for a second time. It’s also his first victory on the Nordschleife. Both achievements are celebrated in the restaurant beneath the main grandstand.

8th A failed transistor box halts Clark’s Type 35 after seven laps of the F2 Kanonloppet at Karlskoga, Sweden. Although Brabham wins, the Daily Express headline reads: “Jim Clark Loses”.

10th Clark tests the latest Type 38 Indycar, chassis 4 – though it’s actually the fifth built – at Snetterton. Its symmetrical suspension (to suit right- as well as left-handers), larger brakes and five-speed ZF gearbox allow him to lap at F1 speeds using just two gears.

14th Clark puts the venerable chassis R6 on pole by four tenths for the F1 Mediterranean GP at Sicily’s Enna-Pergusa speedbowl.

15th A slow start puts him on the back foot, however, and it’s team-mate Spence who takes the fight to Siffert’s Brabham-BRM – until a stone in the face causes the Englishman to crash. Clark’s two-valve engine has sufficient grunt to set fastest lap, but it falls four tenths shy in the final dash to the flag; for a second consecutive year, the feisty Swiss denies him victory in this race.

20th Clark and Chapman fly in the latter’s plane (soon to be sold to Clark) from North London to Delémont, capital of Switzerland’s Jura canton.

21st Starting at 6.30am, Clark completes six practice runs of the winding St-Ursanne-Les Rangiers hillclimb – in a 495bhp Indycar! His best beats the old record, but Siffert’s nimble Brabham-BRM is 3.6sec faster yet.

22nd Rain makes Clark’s task even more difficult. Despite mud on the road, his second run – 2min 43.9sec – is 7sec faster than his first. Siffert’s FTD is 2min 25.1sec and he wins on aggregate over two runs.

28th An up-and-down day at Brands Hatch. Clark qualifies second in his Cortina (behind Brabham’s Mustang) and third in his F2 Type 35, but his new 5.7-litre V8 (an extra 100bhp) Lotus 40 sports-prototype is barely finished and he can do no better than the seventh row after five minutes of seat-time. He then dashes to contest the Swiss GP – a round of the world sportscar championship at Ollon-Villars hillclimb – in the Indycar.

29th Having missed official practice, he undertakes three trial runs of the five-mile course that rises from the Rhône valley. A cracked suspension upright is discovered after the first and is welded. He clocks 4min 34.5sec on his second, but a misfire ruins the third. That problem persists and blights his run proper: 10.8sec slower than in practice, he’s 35.5sec behind Lodovico Scarfiotti, overall winner in a Ferrari Dino 206P.

30th Chapman collects Clark from Heathrow and flies him to Brands Hatch for its inaugural August Bank Holiday meeting. The latter will soon be wondering if the rush has been worth it. Though his Type 35 wins the F2 Eagle Star Trophy, he suffers four incidents/accidents elsewhere.

The Type 40’s Hewland gearbox – in place of the 30’s ZF – suffers gremlins in the first 30-lap heat of the Guards Trophy and Clark spins on two occasions when it selects neutral; he finishes eighth, two laps down. A locking front brake – a Lotus development of three-pad calipers clamping vented discs – deposits him in the ditch at Clearways during the second heat. To cap it all, his Cortina team-mate Sears spins him on the opening lap of the Ilford Films Trophy. On its fourth lap, Clark cuts cheekily across the grass at Bottom Bend to pit because of a puncture. He’s allowed to resume and sets a spectacular lap record before being halted by an ignition short. This is fixed trackside by a mechanic – a disqualification offence – but he pits again, this time to complain about the steering.

September

10th Clark divides his time between chassis R11 and R6, the latter still fitted with its old-spec V8, during the three-and-a-half-hour afternoon practice session for the Italian GP at Monza. He sets second-fastest time in the former.

11th In the four-valve R11, he is the only man to go below 1min 36sec and so wins the 200,000 lire on offer for pole.

12th Though he leads the first two laps, it’s apparent that he cannot shake off the slipstreaming BRMs of Stewart and Hill. Clark leads 19 laps in total and sets the fastest lap – 133.427mph on lap 46 – before dropping from the lead battle on lap 64 (of 76) because of a malfunctioning fuel injection pump.

17th Clark qualifies fourth for the F2 Oulton Park International Gold Cup – its afternoon session ruined by rain – and is beaten to the BSCC pole by Brabham’s Alan Brown-run Mustang.

18th A parachute display is cancelled because of high winds, but the racing goes on. From the outside of the front row, Clark is leading the Gold Cup when he spins under heavy pressure at Cascades on lap eight (of 40). He rejoins in 16th place and sets joint fastest lap during a brilliant recovery drive that sees him finish sixth and claim the point that wins him the Autocar British F2 Championship. He leads the 19-lap BSCC race, too, but is soon overtaken by Brabham. The latter wins on the road, only to be disqualified one week later for using non-homologated engine parts. Of more immediate concern to Clark is the fact that Brabham’s plane seems dangerously low on fuel. A young Geoff Brabham breezily tells everyone not to worry and they make an unscheduled but very necessary stop at Coventry en route to London. In other news: Ford is to fund a 3-litre F1 engine built by Cosworth for Team Lotus.

22nd Clark receives the freedom of the Burgh of Duns.

25th He qualifies third for the F2 race at Albi.

26th Although Brabham’s 16-valve Brabham-Honda starts from pole and sets the fastest lap, Clark’s Type 35 pips it to victory by eight tenths after 192 miles.

October

1st Another oil leak on his four-valve Climax forces Clark to swap to Spence’s 16-valve Type 33, chassis R9, during the opening four-hour practice session for the United States GP at Watkins Glen. He sets second-fastest time in it but also suffers a grassy moment when he selects the wrong gear.

2nd His engine not yet fixed, he begins this session in Mexican team-mate Moises Solana’s chassis R6 – and ends it back in Spence’s after the repaired engine strips its timing gears. Despite setting the day’s best time in R9, Clark elects to start from second on the grid in R11, after the four-valver is re-repaired using parts from the Brabham unit rejected by Gurney.

3rd Clark battles the pole-sitting BRM of Hill for the lead until his Lotus suffers a broken piston on lap 12.

22nd Those engine woes continue when the re-re-repaired four-valve Climax goes bang during first practice at the Mexican GP. Clark is two hundredths slower in Spence’s requisitioned car than the pace-setting Brabham of Gurney.

23rd His Type 33 fitted with the ‘old nail’ cross-crank V8 that took him to victory at the French GP, Clark bucks the trend of a hotter and supposedly slower session with a successful last-minute dash for pole. He is also named by America’s ABC TV channel as Man of the Year of its Wide World of Sports.

24th His ‘trusty’ V8 feeling tight from the start, Clark makes a slow getaway and retires after eight laps when it seizes. His F1 winnings for the year amount to £13,340.

31st A $50,000 purse attracts a stellar sports car field to the 200-mile LA Times GP at Riverside. Clark’s Type 40, now fitted with a 5.8-litre V8, lines up only 13th and finishes 10th in the 20-lap qualification race. In the 77-lap GP, however, he moves stealthily through a dwindling field and finishes second, 5.8sec behind Hap Sharp’s Chaparral.

November

1st Clark and Stewart land at Prestwick Airport, Glasgow, where the assembled press ask the latter about his first-born son Paul, then just four days old, and Clark about his father, Jim Sr, who had collapsed recently at Berwick market.

4th A dapper Clark attends Zandvoort for a Ford Corsair V4 – and tractor! – media launch…

12th His father improving, Clark opens the Scottish Motor Show at Glasgow’s Kelvin Hall…

19th …attends the annual dinner dance of the Scottish Motor Racing Club at Ingliston’s McRobert Pavilion…

24th …and is voted second to world champion road cyclist Tom Simpson in the Daily Express Sportsman of the Year.

26th During a riotous West Essex Car Club dinner dance at Park Lane Hotel, Clark, Chapman, Hill and Les Leston re-enact ‘Zandvoortgate’ and de-bag ‘policemen’ Peters Arundell and Jopp.

December

11th Clark receives five awards at the BRDC’s dinner dance at The Dorchester in London. He wears a kilt of Cameron of Erracht tartan for the occasion.