Guide: Jaguar C-type / 51
Background
Jaguar originally created the XK120 as a design exercise to showcase the firm’s advanced new 3.4-litre dual overhead camshaft straight six engine. The stunning XK120 Roadster was presented at the London Motor Show in October 1948 and caused such an overwhelmingly positive response that Jaguar boss, William Lyons, decided it should be offered to the public.
Following an intensive development programme, production versions began to emerge from Jaguar’s Coventry factory in June 1949.
As a result of its slippery aerodynamic profile and powerful engine, the XK120 could rightfully claim to be the fastest production car in the world.
In addition to a series of highly publicised record-setting speed runs, the XK120 also impressed on track. During 1950, a batch of six Semi-Works Competition XK120s achieved a host of fine results.
Among these, Leslie Johnson finished fifth at the Mille Miglia and looked set for a potential win at Le Mans until clutch failure forced him to retire while lying third.
Stirling Moss won the Dundrod Tourist Trophy, Peter Walker won the Silverstone 1 Hour Production Car race (an event won by Leslie Johnson with a standard XK120 in 1949) and Ian Appleyard took victory on the Alpine Rally.
These outings proved the XK120 had the durability to compete at the toughest endurance events, but such was the pace of development that, to win at the highest level going forward, the XK120’s weak spots would have to be addressed.
Most obviously, the heavy MkV-derived box-type chassis had to go in favour of something lighter. Also, the existing body (that used an ash framework to support some of its aluminium panels) would have to be changed for something lighter and even more aerodynamic.
After Jaguar launched the MkVII in October 1950, William Lyons gave the green light for a re-modelled XK120-based machine. He created a new racing department which was given until June 1951 to design, manufacture and test a car from a clean sheet of paper. Lyons wanted a team of three works cars to appear at the 1951 Le Mans 24 Hours.
Officially dubbed XK120-C, the resultant C-type, was Jaguar’s first ever purpose-built racing car.
It used uprated running gear from the standard XK120 and a new lightweight chassis that was draped with a pared down aluminium body designed to efficiently cut through the air.
The first C-type was finished in mid May of 1951 and broke cover at the Le Mans 24 Hours a few weeks later.
Chassis
To save weight, improve handling and increase torsional rigidity, each C-type was constructed around a new tubular steel chassis designed by Jaguar’s Chief Engineer, William Heynes. At 2438mm, the wheelbase had been shortened by 159mm.
The XK120’s independent front wishbone suspension with its torsion bars, telescopic dampers and anti-roll bar was retained.
The live back end was significantly modified; the semi-elliptical springs of the XK120 were replaced by a single transversely mounted torsion bar connected to the axle by trailing arms. Torque reaction members prevented any lateral movement.
As per the XK120, 12-inch Lockheed drum brakes were fitted all round. At 6 x 16-inches, the centre-lock wire wheels had been widened by an inch. They were originally shod with Dunlop tyres. Track was identical at both ends (1295mm) which represented a 25mm gain at the rear compared to the XK120.
The XK120’s 14 gallon fuel tank (63.6-litres) was replaced with an enormous 39 gallon unit (177.3-litres). This was now mounted behind the rear axle.
Engine / Gearbox
The C-type’s engine was developed by Harry Weslake who served as a consultant engineer to Jaguar.
Weslake created an improved cylinder head with modified inlet port. He added high-lift camshafts, uprated pistons and a lightened flywheel. A dual exit straight through exhaust system was also fitted.
Otherwise, the William Heynes-designed straight six engine, arguably the most advanced mass produced power unit of its day, was more or less unchanged.
It comprised a cast-iron block and aluminium alloy head with dual overhead camshafts, hemispherical combustion chambers and inclined valves. A wet-sump lubrication system was retained along with single plug ignition, a Lucas B12 coil, two SU H6 sidedraught carburettors and an 8.0:1 compression ratio.
As a result of the Weslake modifications, peak power went from 160bhp at 5000rpm to 200bhp at 5800rpm.
The torque rating was now 220lb-ft at 3900rpm compared to 195lb-ft at 2500rpm for the standard XK120.
Transmission was once again via a Moss four-speed manual gearbox.
Bodywork
The C-type’s handsome body was also designed by William Heynes who, thanks to his links with the aviation industry, was able to secure the use of a wind tunnel where a range of wooden models were tested.
During the early development stages, a Fastback roof and rear wheel spats were trialled. However, tests showed neither feature was required. The finished article emerged as a simple Spyder design.
The voluptuous new body was characterised by its low profile, short overhangs and flat sides.
At the front, faired-in headlights were mounted behind Plexiglas covers. In the centre was a rounded grille that fed fresh air into the radiator and engine bay. Cooling was further improved thanks to a bank of sloping vents down each flank and another two banks atop the bonnet. The sills were cutaway so the side-exiting exhausts did not disrupt the airflow.
For the same reason, the centre-mounted rear view mirror was encased within an aerodynamic cowl and the passenger side of the cockpit was covered by a rigid body coloured tonneau. In the absence of a conventional windscreen, a simple aeroscreen was provided for the driver.
The truncated back end was home to a spare wheel hatch and quick fuel filler.
Compared to the XK120, the C-type was 406mm shorter, 76mm wider and 165mm lower.
Like its production sibling, the C-type’s lightweight aluminium body was fabricated by Abbey Panels in Coventry.
Interior
Aside from a pair of leather-trimmed bucket seats and a transmission tunnel covered with ribbed matting, there was little interior trim to speak of. Instead, the cockpit was left in bare metal to save as much weight as possible.
Behind the three-spoke Bluemels steering wheel was a simple satin black instrument binnacle that housed large read outs for road and engine speed. Smaller gauges for fuel, oil pressure, oil temperature, water temperature and battery condition were also provided.
Weight / Performance
As a result of its lightweight chassis, skimpy bodywork and stripped-out interior, the C-type weighed in around 235kg lighter than an alloy-bodied XK120 (965kg compared to 1200kg).
The 0-62mph time dropped from a little over nine seconds to under six.
Top speed went from 125mph to 145mph.
Production
Upon completion in early June, the first C-type, chassis XKC001, was given a shake down at the Motor Industry Research Association test track in Warwickshire. It was then taken to Silverstone where Stirling Moss, Peter Whitehead, Peter Walker, Jack Fairman and Leslie Johnson all got a chance to drive.
News of the car broke when Jaguar released a press release the week before Le Mans.
Chassis XKC001 was road registered 032 RW, chassis XKC002 was 210 RW and chassis XKC003 was 153 RW.
The three cars were completed in the nick of time, after which they were driven from Coventry to Le Mans accompanied by a lorry filled with spares.
They would be raced by Stirling Moss / Jack Fairman (002), Peter Walker / Peter Whitehead (003) and Leslie Johnson / Clemente Biondetti (001).
1951 Le Mans 24 Hours
Ferrari’s fast and powerful 4.1-litre 340 Americas (run under Luigi Chinetti entries) were favourites for victory at Le Mans in 1951. Chief opposition was expected to come from the 4.5-litre Talbot-Lagos and 5.5-litre Cunninghams.
Grid slots for the race (which took place over the weekend of June 23rd and 24th) were decided on engine size. The Jaguars lined up in 20th, 22nd and 23rd positions.
The practice days were not without incident.
Chassis XKC001 (Johnson / Biondetti) had to have its engine rebuilt.
The Marchal headlights fitted to all three cars proved inadequate and more powerful examples were ordered which required new bowls to be made.
During one of the wet evening session, Moss (XKC002) had a lucky escape when Rudolph Sauerwein lost control of his works Porsche 356 SL and rolled right in front of the Jaguar. Moss was forced to take evasive action and collided with the tail of Mortimer Morris-Goodall’s Aston Martin DB2. Fortunately, the damage was slight and XKC002’s nose was repaired in time for the race.
Meanwhile, the Jaguars had set a series of very fast times which gave the team much confidence.
The race got underway at 4pm on Saturday in damp, overcast conditions.
The Allard J2s of Tom Cole and Peter Reece streaked away off the line, but by White House corner, the Talbot-Lago T26 GS of Froilan Gonzalez had assumed the lead. Moss was hard on the Argentine’s heels followed by Cole’s Allard, Biondetti’s C-type, Eugene Chaboud’s Talbot-Lago T26 GS and Peter Walker’s C-type.
By lap two, Cole’s Allard was nowhere to be seen and Gonzalez-Moss had built an appreciable gap between themselves and third placed Biondetti. Moss then roared into the lead at the end of lap three.
Unfortunately, on lap five young Frenchman, Jean Lariviere (driving the Johnny Claes Ferrari 212 Export), overshot Tertre Rouge and sustained fatal injuries when the car left the track, jumped an embankment and ended up in someone’s back garden. Poor Lariviere sustained a massive neck trauma and was killed instantly.
During the second hour, Moss moved a lap clear of the second-placed Talbot-Lago which was now being hotly pursued by the other two Jaguars, both of which were being driven to strict instructions. An hour later, Biondetti and Walker had a full lap advantage over the Talbot-Lagos of Louis Rosier and Pierre Meyrat in fifth and sixth.
The fourth hour saw the Jaguars move into first, second and third positions. However, a short while later, the second-placed Biondetti / Johnson C-type had to be withdrawn; a cracked oil feed pipe led to a loss of oil pressure and nothing could be done as the rules only allowed the use of parts and tools that were carried in the car.
At quarter distance, Moss / Fairman were still lap clear of the Walker / Whitehead sister car with Juan Manuel Fangio / Louis Rosier third for Talbot-Lago. By this time, damp conditions had turned into heavy rain.
During the ninth hour, Moss’s incredible run came to an end. The oil pressure reading in XKC002 dropped to zero after an oil feed pipe cracked as a result of vibration. Before Moss had a chance to switch off, a connecting rod blew through the side of the crankcase on the approach to Arnage. Nevertheless, Moss’s brilliant drive had broken the Ferrari and Talbot-Lago challenge and he had established a series of new lap records.
This left the Walker / Whitehead car as the sole C-type representative. It was just under a lap clear of the best placed Talbot-Lago which was now the Froilan Gonzalez / Onofre Marimon example. Shortly afterwards, the Fangio / Rosier entry packed up and was pushed away.
Despite the terrible overnight weather, the Walker / Whitehead Jaguar pressed on without issue. Behind it, the Phil Walters / John Fitch Cunningham C2-R moved into second place ahead of the Lance Macklin / Eric Thompson Aston Martin DB2 in third.
By 10am on Sunday morning, XKC003 was eight laps clear of the Cunningham.
At midday, the Pierre Meyrat / Guy Mairesse Talbot-Lago had moved into second having passed the Macklin / Thompson DB2 and the now-stricken Cunningham. The Jaguar was by this time ten laps clear of its closest challenger and cruised home to victory.
Walker / Whitehead broke the existing distance record with an hour to go and Jaguar became the first British marque to win at Le Mans since Lagonda in 1935.
1951 Dundrod Tourist Trophy
Following Jaguar’s victorious outing at Le Mans, the C-types were not seen again until mid September when the same three cars attended the Dundrod Tourist Trophy in Northern Ireland (September 15th).
Stirling Moss, Peter Walker and Leslie Johnson were entered in the cars they had driven at Le Mans (XKC002, XKC003 and XKC001 respectively). Moss and Walker would drive the 318 mile handicap event single-handedly while Johnson was accompanied by Tony Rolt.
Stiff opposition was expected from the brand new 2.6-litre Aston DB3 (accompanied by a brace of works DB2s), plus a fleet of cars from Frazer Nash, Ferrari and Allard.
The 2pm start got underway with the drivers sent off in batches according to their time allowances and credit laps.
Eddie Hall crashed his much-fancied Ferrari 340 America on the first lap as did Eric Winterbottom whose Frazer Nash Le Mans Replica went off at Wheeler’s Corner. The unfortunate Winterbottom succumbed to his injuries the next day.
On the second lap, Moss posted the first of several new lap records, but the complicated handicap system led to much confusion among the spectators for the first half of the race.
However, by 4pm (just passed mid-distance), Moss had established an unassailable lead with team-mate Walker now lying second. Bob Gerard’s Frazer Nash Le Mans Replica was third after the fast DB3 Aston of Lance Macklin had been forced to retire.
When Tony Rolt took over from Leslie Johnson in the other C-type, he set a series of flying laps and began to close the gap to the leaders.
At 5pm, the order was Moss (C-type), Walker (C-type), Gerard (Frazer Nash), Pitt (Frazer Nash), Abecassis (DB2), Shawe-Taylor (DB2) and Baird (Ferrari 212 Export). On the next lap, Rolt was promoted to fifth after he overtook both the Shawe-Taylor DB2, Baird’s Ferrari and the Abecassis DB2 (which retired). Rolt then went past Pitt to take fourth spot but could do nothing about Gerard in third.
Moss ultimately took the win from Walker by over two-and-a-half minutes.
1951 Goodwood International Sports Car Race
The final two 1951 outings for the C-type were made at Goodwood on September 29th.
Chassis XKC001 (the Johnson / Biondetti Le Mans entry and Johnson / Rolt TT machine) was trucked down to the south coast for Stirling Moss to race in conjunction with his single seater drive for HWM that weekend.
Against a field of mostly Frazer Nashes and Jaguar XK120s, Moss proved unbeatable in the opening five-lap Sports car contest. He established a big lead and went on to cross the line 13 seconds ahead of David Clarke’s Frazer Nash which snatched second from the similar car of Rodney Peacock.
1951 Goodwood International Handicap Race
Later that day, Moss repeated his success from the scratch mark in the handicap race. He completely dominated and in retrospect the organisers should most likely have given the Frazer Nashes more than an eight second head start.
Driving a Healey Silverstone, John Edwards retained his advantage for a couple of laps, by which time Moss had already moved up to fifth place.
Before long, Moss had established a tremendous lead and, thanks to the XK120s of Hugh Howarth (18.6 seconds back) and Phillip Fotheringham-Parker (a further three seconds back), Jaguar scored a 1-2-3 finish.
Moss also set a new sports car lap record.
Jaguar would return for the 1952 season when C-type deliveries to customers would begin.
Text copyright: Supercar Nostalgia
Photo copyright: Jaguar Heritage Trust - https://www.jaguarheritage.com/
