mild-steel rear bulkhead. With two lower
bolts, set an inch wider than Clark’s butt,
absorbing the shear and two thin steel
“fish plates” extending from the rocker
covers and slotted into the tub to allow
for expansion, the DFV is a fully-stressed
member – at Duckworth’s insistence rather
than Chapman’s, according to Costin – and
the gearbox and suspension hang from it.
With a buzz-saw sound from its flat-plane
crank, chosen to create two “fours” and
keep the exhaust routing simple, it’s
neater, smaller and lighter than its
12-cylinder rivals and relatively frugal.
Costin – the practical counterbalance to
Duckworth’s theoretical – is the first to drive
it. His runs along Hethel’s runway are halted
when the AP clutch fails. A Lotus Cortina
is cannibalized for its Cosworth twin-plate
assembly (with peg drives) and the
shakedown continues. Once 2.5in of
unwanted rear toe-out is discovered and
adjusted, it goes well. Scammell also drives.
Tuesday, May 9
Costin and Duckworth fly Chapman’s
loaned Cherokee 260 – skirting a hovering
Harrier “Jump Jet” mid flight – to
Snetterton, where Costin soon discovers
a serious problem: 49’s upper rear-radius
rods’ brackets are kinking under load,
rippling the tub’s skin. The test is halted.
Tuesday, May 23
Hill is finally summoned to test –
Duckworth, who’d briefly understudied
him as Lotus’s gearbox guy, is not a fan of
Hill’s feedback. After a few laps of
Snetterton, he pronounces 49, “Not a
bad old tool. It’s got some poke.” Even so,
the job list runs to more than 80 items.
Thursday, June 1
Tax exile Clark drives from Paris to
Zandvoort, Holland. Accompanying him
in his Lotus Elan is friend and landlord
Jabby Crombac, an influential French
motorsports journalist. The Scot heads
straight for the pits. Although he’s seen
chassis jigs, drawings and photos of the
49, this is the first time he’s seen it in the
flesh. Chassis R2, its build delayed by
the necessary reinforcing of its tub,
has yet to turn a wheel.
Friday, June 2
Driving the car as it arrived, i.e., on Hill’s
settings, Clark tackles the first of three
practice sessions for the Dutch GP. With
a new gearbox fitted during lunch – the
five-speed ZF is incapable of ratio
changes and Duckworth would rather
Chapman had used the more adaptable
A former journalist,
Hayes switched to
with Ford of Britain.
Le Mans program,
his championing of
the Cosworth DFV
Ford’s image in
the mid 1960s.
After spark plug problems in Belgium and a transmission failure in France,
Jim Clark took a second win for the DFV-powered Lotus 49 in the British
Grand Prix at Silverstone (MAIN). The Scot converted pole into an early lead,
but was passed by teammate Graham Hill on lap 26. After Hill slowed with
suspension problems on lap 55, Clark re-took a lead he’d hold until the end.
Hill’s DFV failed on lap 64, giving him his fourth straight DNF.
BACK TO WINNING WAYS
28 SEPTEMBER 2017
FORMULA 1: LOTUS 49-FORD