Guide: Jaguar D-type / 54
Background
In early 1953, Jaguar began planning a successor to the C-type which was still among the best sports racing cars available.
In 1951, the C-type had won the Le Mans 24 Hours first time out and this maiden victory was followed by another in 1953. However, while the C-type was still at the top of its game in 1953, the speed of development in top flight sports car racing meant its shelf life was limited.
With this in mind, Jaguar boss, William Towns, sanctioned a replacement to come on stream in 1954.
The appropriately named D-type was developed over an 18 month period and featured a radical new monocoque construction.
The concept was initially trialled with an experimental C-type mule known as the XP/11.
During the XP/11’s development programme, Jaguar test driver, Norman Dewis, drove it down the closed Jabbeke highway in Belgium where it hit 179.8mph. Had the car not suffered a persistent misfire, Dewis claimed 190mph would easily have been possible.
The D-type that followed was arguably the most advanced sports racing car of its era.
Chassis
The D-type’s central tub monocoque was fabricated from 18 gauge magnesium alloy. A tubular aluminium subframe was arc-welded in place to carry the engine and front suspension.
Compared to the C-type, the wheelbase was six-inches shorter (7ft 6in). Track was two-inches narrower at the front and three-inches narrower at the rear.
The suspension layout closely followed the outgoing model: double wishbones and torsion bars at the front, a solid axle with trailing links and a transverse torsion bar at the back. Telescopic dampers were fitted all round.
The C-type’s state-of-the-art 12 ¾-inch Dunlop disc brakes were retained. A Plessey servo pump was driven by the propshaft.
Instead of traditional wire wheels, Jaguar adopted centre lock cast alloy rims for the D-type. Wheel size was 16 x 5.5-inches and Dunlop tyres were used.
A 37 gallon (168-litre) fuel tank was installed over the rear axle.
Engine / Gearbox
In the engine bay was a further uprated version of Jaguar’s dual overhead camshaft straight six.
Now equipped with dry-sump lubrication and an oil cooler, the engine was mounted at an angle of 8° to minimise the car’s frontal area.
As before, the engine used a cast-iron block and light alloy head with two valves per cylinder and single plug ignition. The first four D-types retained the original C-type head.
Displacement came in at 3442cc thanks to a bore and stroke of 83mm and 106mm respectively.
Fuel feed was courtesy of three sidedraught Weber 45 DCO3 carburettors.
The compression ratio was 9.0:1.
In this configuration, peak output was 250bhp at 6000rpm and 242lb-ft at 4000rpm.
The gearbox was a new four-speed all-synchromesh unit manufactured in-house. A Borg & Beck twin-plate clutch was retained. A limited-slip differential would not arrive until the Le Mans race in 1955.
Bodywork
Bodywork was designed by Jaguar aerodynamicist, Malcolm Sayer. Derived from the XP/11, it featured a semi-enclosed cockpit, wraparound driver’s screen and headlights mounted behind clear plastic covers.
Driver and passenger compartments were separated by a body coloured metal panel that formed part of the monocoque’s outer skin.
Fresh air was fed to the radiator by a large oval nose intake. To the left of the intake was an additional faired-in spot light.
For improved high speed stability, the streamlined headrest was given a large vertical fin. Even the rear-view mirror was housed in a streamlined cone.
For races, the passenger side of the cockpit was usually covered by a rigid body coloured tonneau.
Compared to its predecessor, the D-type was 3-inches shorter and three-quarters of an inch narrower. Because of the enormous vertical fin, it stood 15.5-inches taller.
As per World Sportscar Championship regulations, a full complement of lighting was installed to make the car road legal.
Interior
The seats, head rest, driver’s thigh pad and gear gaiter were trimmed in leather. The rest of the cockpit was left in bare metal.
Instrumentation generally comprised an 8000rpm rev counter plus smaller gauges for oil pressure and water temperature. Some later cars also came with a 180mph speedometer.
In most cases, early cars had their instruments located off to the driver’s left-hand side.
The wood-rimmed steering wheel came with three drilled aluminium spokes.
Weight / Performance
Overall weight was around 860kg and 0-62mph took about 4.7 seconds depending on gear and axle ratios.
At Le Mans, the D-types were hitting 180mph thanks in part to their incredibly small frontal area.
Prototype
The first example, chassis XKC 401, was completed in early April 1954.
On April 13th, XKC 401 was tested at the Lindley RAF base. Another session then took place at Silverstone on May 3rd.
By May 8th, the prototype was in France for some pre Le Mans trials. On closed roads, Tony Rolt set a new unofficial lap record. He averaged over 115mph and exceeded 170mph down the Mulsanne Straight.
Upon its return to England, the bare alloy prototype was presented to select members of the press during the second week of May. This was followed by an appearance at the new MIRA high speed test track on May 21st.
1954 Season
Jaguar’s 1954 competition programme for the D-type comprised three events: the Le Mans 24 Hours, the Reims 12 Hours and the Dundrod Tourist Trophy.
Le Mans and the TT were rounds four and five of the 1954 World Sportscar Championship. The race at Reims was a stand-alone event held in support of the French Formula 1 Grand Prix.
1954 Le Mans 24 Hours
Jaguar entered three brand new D-types for Le Mans which took place over the weekend of June 12th and 13th. The cars were so new that they hadn’t even been painted by the time they arrived at la Sarthe.
The driver line up was kept pretty much the same as 1953 with winners Tony Rolt / Duncan Hamilton in chassis XKC 402 and runners up Stirling Moss / Peter Walker in XKC 403. Peter Whitehead was paired with Ken Wharton in the third car (chassis XKC 404).
The biggest threat to the Jaguars came from Scuderia Ferrari who had a trio of five-litre 375 Plus in attendance. Aston Martin would also be in with a shout. The British outfit had four DB3S plus the big banger Lagonda DP115. Additionally, works cars from Gordini and Cunningham were quite capable of taking the win.
Lancia did not attend and the Maserati transporter broke down en route which meant they missed scrutineering and weren’t able to compete.
Both Ferrari and Jaguar did practice laps in excess of 118mph, but as usual, grid positions were decided on engine size which meant the superbly turned out D-types started 12th, 14th and 15th. There was no 13th position grid slot for superstitious reasons.
The race began at 4pm under dark clouds. Jean Blanc was first away in his Talbot T26 GS, however, by the Dunlop Bridge, he had been consumed by three Ferraris and Briggs Cunningham’s C4-R.
At the end of lap one, the Ferraris of Gonzalez, Marzotto and Manzon led the D-types of Moss, Rolt and Wharton. Wharton’s car already had damage to its nearside front wing; evidence of a minor coming together during the start line melee.
Heavy rain arrived five laps in, which negated Ferrari’s power advantage.
Moss moved up to second. He briefly led at the 90 minute mark, by which time the rain was really coming down. Moss, Gonzalez and Marzotto exchanged the lead several times on their way to establishing a one lap lead over the rest of the field. Rolt held back in fourth while Wharton was delayed with a blocked fuel filter.
Soon after he had taken over from Moss, Peter Walker’s D-type stopped out on track for 50 minutes with another blocked fuel filter.
By 9pm, the best placed Jaguar was that of Rolt / Hamilton in fourth as the Moss / Walker and Whitehead / Wharton cars steadily hauled themselves back into contention.
At 11pm, the Marzotto / Maglioli Ferrari retired with gearbox trouble and the Whitehead / Wharton D-type moved up to second.
Shortly after midnight, Moss became the first D-type retirement when his brakes failed at the bottom of the Mulsanne Straight.
By 2am, the Ferrari of Rosier / Manzon had moved up to second behind Gonzalez / Trintignant and the Rolt / Hamilton D-type was third (two laps behind the leaders). Jaguar team-mates Whitehead / Wharton were fourth after a lengthy pit-stop to address another fuel feed problem. In the 13th hour this car became the second works Jaguar retirement: a blocked fuel line and transmission trouble caused it to be pushed away.
As dawn broke, the Ferrari of Rosier / Manzon (which had been overtaken for second by Rolt / Hamilton) was retired with a broken gearbox. This left the works Ferrari and Jaguar teams with one car each.
Gonzalez / Trintignant held a two-lap advantage until 9:30am, when the Ferrari had trouble re-starting after a pit-stop. The Jaguar was less than three minutes behind, but around the same time, Rolt glanced the bank coming out of Arnage while lapping a slower car and two minutes were lost in the pits for some impromptu panel beating.
With less than two hours to go, the Ferrari lost another seven minutes when it again failed to re-start. The Italian mechanics traced the problem to saturated ignition wiring and Gonzalez finally got going with three minutes in hand. Hamilton whittled this down to 90 seconds at one stage, but when the rain eased off in the final half hour, Gonzalez was able to pull away and ultimately took the win.
Third place went to the Cunningham C4-R of Bill Spear and Sherwood Johnston who were 17 laps in arrears.
Later it emerged Gonzalez and Trintignant should have been disqualified for receiving an illegal push start during one of their pit stops.
1954 Reims 12 Hours
Three weeks after Le Mans, France hosted the Reims 12 Hours which started at midnight and ran until noon on July 4th. Immediately after the twelve hour sports car race, the French Formula 1 Grand Prix took place which ensured a strong turn out of entrants and spectators.
The only works Ferrari on hand for the sports car race was a solitary 750 Monza. Briggs Cunningham had a brace of his Cunningham C4-Rs in attendance and there was a full squad of Gordinis and Maseratis as well.
Jaguar arrived with the same car and driver pairings used at Le Mans. Once again, grid positions were determined on engine capacity.
At the end of lap one, Moss thundered past the pits in the lead. He was chased by one of the Cunninghams with Wharton’s D-type third.
The next time round, Moss, Wharton and Rolt were first, second and third for Jaguar. Meanwhile, Maglioli’s works Ferrari had moved up to fourth and, with 15 minutes gone, the Italian was second and closing on Moss. By this time, the rain had begun belting down.
At the one hour mark, Moss led Maglioli by 13 seconds. However, soon afterwards, the Ferrari dropped out with gearbox problems which promoted Wharton’s D-type to second.
Around this time, Rolt’s Jaguar was pranged by Jean Behra’s Gordini and both cars headed for the pits. Although the back of Rolt’s car was rather bashed in, he was able to continue while the Gordini was forced out of the race.
Just before 2am, Moss stopped for a plug change and lost six minutes which dropped him to fourth. However, by 4am, the Jaguars were running first, second and third again with Moss / Walker two laps ahead of both Rolt / Hamilton and Whitehead / Wharton. The Cunninghams were fourth and sixth with the privateer Masten Gregory / Clemente Biondetti Ferrari 375 Mille Miglia sandwiched in between.
As 5pm approached, Peter Walker retired the lead D-type with a broken driveshaft.
By 6am, the two remaining D-types and the lead Cunningham were all on same lap: Whitehead / Wharton were in the lead with Rolt / Hamilton second and Walters / Fitch third. The second Cunningham was fourth, some six laps in arrears.
The Jaguar crews made their final driver changes at 10am with two hours to go.
Rolt handed the lead car over to Hamilton and Wharton gave way to Whitehead with the second placed car now a lap behind.
However, with 30 minutes to go, Hamilton came into the pits with funny noises coming from his rear axle; the earlier shunt with Behra’s Gordini had caused part of the frame to chafe the axle casing and its oil had disappeared. Twelve minutes were lost as the hole was welded up which allowed Wharton / Whitehead through to take the D-type’s first win.
Fortunately, Hamilton / Rolt held on to second spot.
1954 Brighton Speed Trials
After an absence of two months, Jaguar ran one of their D-types (XKC404, the Reims 12 Hours winner) at the Brighton Speed Trials on September 4th. Norman Dewis was on driving duty for a couple of demonstration runs between the proper timed sessions.
The event got underway at 9:30am in rainy conditions, but by the time Dewis appeared the weather had brightened up and the promenade had dried out. He clocked a best time of 26.14 seconds to set an unofficial sports car record.
1954 Dundrod Tourist Trophy
Jaguar’s next appearance of 1954 came at the Dundrod Tourist Trophy handicap event on September 11th.
Three cars were again taken, two of which ran Class C 2.5-litre engines in an attempt to give them the best chance of overall victory. These short stroke 2482cc machines were tasked with an average speed target of 82.77mph over 86 laps while the solitary Class D 3.4-litre example was set the same target as the 3.8-litre Lancias: 86.62mph over 90 laps.
The 2.5-litre engines were fitted to a brand new car for Stirling Moss / Peter Walker (XKD 406) and the ex- Moss / Walker chassis from Le Mans and Reims (XKC 403) which, for this event, was driven by Peter Whitehead / Ken Wharton.
Tony Rolt and Duncan Hamilton drove the same car they had used at Le Mans and Reims (XKC 402) which was fitted with the standard 3.4-litre engine.
Factory teams from Ferrari, Lancia, Maserati, Lotus, Frazer Nash and HWM were all in attendance, but it soon became apparent the 750cc class DB Panhards had been given an artificially low target for laps and speed.
Ascari’s Lancia D25 was the fastest car in practice followed by Ulsterman Desmond Titterington’s privateer Ferrari 750 Monza.
The night before the race, the Jaguar mechanics were busy until the early hours of the morning cannibalising a couple of engines to rebuild Moss’s 2.5-litre unit; one piston had a gaping hole through the crown while the combustion chamber above was a rough and ragged cavity. Nevertheless, all three D-types managed to take their place on the grid.
Ascari’s Lancia D25 was first away followed by Hawthorn in the Ferrari 750 Monza and Moss’s 2.5-litre Jaguar.
Hawthorn got his Ferrari ahead of Ascari on the opening lap and Rolt moved up to third in the big D-type, but he was soon demoted by Taruffi’s Lancia and then the Aston Martin DB3S of Peter Collins.
Over the next few laps, Hawthorn and Ascari traded lap records while the 3.4-litre Jaguar continued to drop back. In Class D, Moss led Whitehead as expected given they had two laps in hand over the bigger-engined Astons.
The frantic pace soon began to tell; first Fangio’s Lancia dropped out from third in Class C and Collins came walking in from Quarry after his Aston broke a universal joint.
Then Wharton brought his 2.5-litre Jaguar in with a flat rear tyre. The wheel was changed, the tanks replenished and Peter Whitehead took over. Other drivers came in for their first stops shortly afterwards.
At this stage, some two-and-a-half hours in, the DB Panhards were first and second, Hawthorn / Trintignant were third in their 750 Monza and Moss / Walker were fourth in the 2.5-litre Jaguar.
After 34 laps, Duncan Hamilton retired the 3.4-litre Class D Jaguar with falling oil pressure.
As the race wore, on both 2.5-litre Jaguars developed misfires.
The closing stage saw Ascari retire his Lancia with ignition bother while Moss toured in with the Class C-leading D-type. He came to a stop just short of the finishing line and waited 45 minutes until the winning DB Panhard crossed the line in order to class as a finisher.
Laureau / Armagnac were declared winners with Hawthorn / Trintignant second and Musso / Mantovani third in their Maserati. Whitehead / Wharton were classified fifth in the 2.5-litre D-type with the sister car of Moss / Walker 18th.
In terms of distance covered, Hawthorn / Trintignant finished just over two minutes ahead of Taruffi (Lancia D24) who had been joined by Fangio. The sister car of Robert Manzon / Eugenio Castellotti was two laps down in third. Whitehead / Wharton were sixth (second in the under three-litre class) and Moss / Walker 14th (fourth in class).
1954 Prescott Hillclimb
A week after the Dundrod TT, Peter Walker gave the D-type its final outing of 1954 at the Prescott Hillclimb (19th September). The international meeting attracted a strong field of cars and drivers; Walker drove XKC404 which had last appeared with Norman Dewis at the Brighton Speed Trials earlier in the month.
Unfortunately, a heavy downpour occurred just before the bigger engined cars came out and Walker found the D-type a less than ideal sprint car in the greasy conditions. He ultimately posted fifth fastest time in class while victory went to the 4.4-litre Mercury-engined HRG of Alex Francis.
Jaguar would be back for an expanded programme in 1955.
Text copyright: Supercar Nostalgia
Photo copyright: Jaguar Heritage Trust - https://www.jaguarheritage.com/
