Blog posts tagged with 'mike kimberley'

On Friday, 16th December 2011 a small group gathered around the XJ13 at Jaguar Heritage to mark the launch of Peter Wilson's book, "XJ13 - The definitive story of the Jaguar Le Mans car and the V12 engine that powered it".

This was no ordinary gathering, as those present included many surviving members of the team that were originally involved in the original XJ13 car as well as the development of the engine that powered it. Those present included Norman Dewis, George Buck, Frank Philpott, Jim Eastick, Ron Greves, Mike Kimberley, Roger Shelbourne, Robert Berry, Peter Taylor and Peter Wilson himself.

Click the images below to see videos and more detail of the proceedings

The videos include introductions by Tony Duckhouse (on behalf of Jaguar Heritage), Paul Skilleter (renowned Jaguar author and publisher) and further insights by Mike Kimberley (XJ13 Project Manager - later to join Colin Chapman and become CEO of Group Lotus):

More details of the book itself are available from Paul Skilleter Books or the Jaguar Clubs of North America.

As the build of the "trial" all-steel monocoque/chassis progresses, I wanted to consider the materials that should be used for construction of the component parts of my final version. Jaguar themselves went through a similar exercise in 1964 when the XJ13 had reached an advanced design stage.

Before then, in the few years leading up to 1964, various studies/reports were made on things such as the shape of the overall body, the design of the underlying chassis structure and suspension design. One, quite advanced, design was for a rather more integrated monocoque design as shown in the following sketch from the November of 1963:

Early monocoque design for the XJ13.
© Image - reproduced with permission.

However, the above design was not progressed further and, instead, a separate monocoque/chassis unit was developed which was to be clothed by a largely unstressed outer skin:

Representation of original XJ13 monocoque/chassis.

In essence, the final design for the monocoque/chassis consisted of three main elements:

The design of the front suspension went through a few different incarnations as the car was being assembled. Derrick White, Jaguar's talented Race-car Engineer argued for a cutting-edge design (for the time) using widely-spaced upper and lower wishbones. This would have given better handling and a greater possibility of maximising the benefit of the wider tyre widths which were increasingly being used in the mid-1960s. His persistent arguments were repeatedly blocked by Bill Heynes who favoured a more tried-and tested production-based suspension. Heynes eventually prevailed and a design, based on the 1964 Lightweight E-Type was adopted - albeit with coil-over shocks in place of torsion bars.

This decision was one of the things that led to Derrick White becoming increasingly frustrated and his eventual defection to Cooper - a great loss to Jaguar. White went on to design the GP-winning Cooper-Maserati of 1966. Heynes, at the time, had been given direct supervision of the XJ13 project and it has been argued that his enormous workload at the time contributed to the slow development of the XJ13. Fortunately, Mike Kimberley was eventually given day-to-day responsibility for the car and development then continued at a greater pace.

Meanwhile, in 1964 when the car had reached an advanced design stage - on paper at least - Jaguar conducted an investigation into the best materials of construction for the chassis/monocoque. They considered mild-steel, aluminium and titanium. The investigation concluded:

In the end, the chassis sections coloured yellow/green in the drawing above were fabricated from mild-steel. The main centre section was fabricated from aluminium.

According to Peter Wilson, who actually lent a hand in constructing the XJ13:

The modern equivalent, Aluminium 5251 (NS4), is available and will be used for the recreation along with steel pressings where appropriate. I must admit to some relief that Jaguar didn't choose titanium

For those engineers amongst you, and those well-versed in the mysteries of things such as Young's Modulus (I certainly don't include myself here!), the following summarises some of the data presented in Jaguar's investigation into material choice:

As is well-known, there is no such thing as a chassis that doesn't flex, but some are much stiffer than others. The choice of material is critical in this respect. The range of chassis stiffness has varied greatly over the years from about 500 lbft/degree in the 1930s to more than 20,000 lbft/deg in a modern race car. I should be able to measure the stiffness of my completed chassis and it will be interesting to compare the all-steel "trial" chassis to the final version.

Different chassis designs each have their own strengths and weaknesses. Every chassis is a compromise between weight, component size, complexity, vehicle intent, and ultimate cost. And even within a basic design method, strength and stiffness can vary significantly, depending on the details. There can be no such thing as the "ultimate chassis" for every car, because each car presents a different set of problems. The XJ13 chassis gave a whole new challenge because of the intention to mount the engine as a fully-stressed member - with the whole of the rear suspension hanging off the engine/transaxle. I believe this would have beaten Colin Chapman's Lotus by a few years had the XJ13 actually raced. Jaguar carried out a number of theoretical investigations into how well the car should stand up to the torsional loads applied to the chassis because of this arrangement and the final rear chassis design took these anticipated loads into account. The front suspension arrangement bears many similarities to the E-Types with steel tubing attached to the front bulkhead and Jaguar will have built up much experience of this design.

It may seem that an aluminium chassis was always the logical choice, but this is not necessarily true. Aluminium is more flexible than steel or titanium. Indeed, the ratio of stiffness to weight is almost identical to steel, so an aluminum chassis must weigh the same as a steel or titanium one to achieve the same stiffness. Aluminium has an advantage only where there are very thin sections where buckling is possible. This certainly applies to the large sill and floor sections.

In the end, the "unintended crash test" crash at MIRA in 1971 demonstrated better than anything else the soundness of Jaguar's basic chassis design. Although there was considerable damage to the outer structure, the basic chassis/monocoque survived almost intact. More importantly, the legendary Test Driver, Norman Dewis, survived unscathed.

The XJ13 first ran in April 1966 and, by the summer of 1967, development was still continuing apace with an extended test at Silverstone in August of that year. This was the ninth test carried out over a period of less than six months which does demonstrate Jaguar's commitment to the project at that time. These tests were carried out with the full knowledge of Jaguar's senior management with test reports widely distributed internally by the project leader - Mike Kimberley.

Michael J. Kimberley (“Mike”) C.Eng., F.I. Mech. E., F.R.S.A., F.I.E.D, F.I.M.I has had a remarkable career in the motor industry over the last 56 years, working with some of the great engineers, innovators and leaders of the worlds motor companies. Mike started as an apprentice with Jaguar in 1953 before rapidly progressing to becoming in Section Leader, Special Projects at Jaguar in 1965 where he lead the team developing the Jaguar XJ13 Le Mans car, under such famous names as Jaguar founder Sir William Lyons and Jaguar race director Frank (Lofty) England ...."

Mike Kimberley - Jaguar XJ13 Project Leader.

During this active development phase it seems that most of the testing was carried out by David Hobbs with additional drives by Richard Attwood and Norman Dewis.

It was David Hobbs who set the closed course record (167.5 MPH) for UK with the XJ13. This record lasted for 19 years. Hobbs' first race was in 1959 driving his mother's Morris Oxford. He turned professional in 1964 and raced extensively world wide for 30 years. His last race driven was the Masters Championship in 1993.

David Hobbs - racing driver and former Jaguar apprentice. Picture taken at the 2009 Motorsports Hall of Fame Induction.

Richard Attwood was born in Wolverhampton, Staffordshire. Richard James David "Dickie" Attwood (born 4 April 1940, Wolverhampton, Staffordshire) is a British former motor racing driver. During his career he raced for the BRM, Lotus and Cooper Formula One teams. In his whole F1 career he achieved one podium and scored a total of 11 championship points. He was also a successful sports car racing driver and won the 1970 24 Hours of Le Mans race, driving a Porsche 917.

Richard Attwood - racing driver and former Jaguar apprentice.

Norman Dewis is Jaguar's legendary Test Driver. Dewis is best remembered for a career spanning 33 years at Jaguar. In the words of Paul Skilleter,

Norman Dewis - Jaguar's legendary test driver.

A quick search of the internet will uncover the commonly-held view that it was an impending change to Le Mans engine capacity regulations alone which led Jaguar senior management to halt further development of the car. However, the truth is perhaps a little more involved than this and it seems a number of factors may have conspired to halt further development of the XJ13.

• An impending change to the Le Mans regulations to limit engine capacity to 3 litres. In Lofty England's own words, in a memo to William Heynes, he stated "... the 3-litre maximum engine capacity formula for Group 6 prototype cars will be applied to all sports car championship races, which includes Le Mans, for the next three years, i.e. up to and including 1970, which period coincides with the remaining period of the current Formula 1 racing car regulations ..."

   

• The spectre of the "GT40 Armada" in 1967. In the spring of 1963, Ford heard that Enzo Ferrari was interested in selling his company to Ford. Ford committed millions of dollars researching and auditing Ferrari's company only to have Ferrari unilaterally withdraw from talks at a late stage. This angered Henry Ford II who directed his racing division to find a company that could help them build a Ferrari-beater on the world endurance-racing circuit. The Ferrari-beater turned out to be the Mark IV GT40 which, although american-built, was based on a collaboration between Ford and England's Lola. Ford did not, at this time, have the racing prowess to take on the likes of Ferrari so had earlier engaged in discussions with England's Lotus, Cooper and Lola - eventually choosing the latter as a partner.

   

• The BMC takeover of Jaguar. On 11 July 1966, the "merger" of Jaguar with the British Motor Corporation was announced. In reality, this was a takeover by BMC of Jaguar, but Sir William Lyons maintained control of most of his his empire. One reason that Lyons agreed to the 'merger' was to get financial backing for future model programmes. Lyons saw Jaguar's future success lay in introducing new road cars. Jaguar's finances were stretched at the time and racing had reached a new level of professionalism and expenditure that Lyons could not now justify.

On the 29th September 1967, Lofty England said:

The fact that Jaguar were actively considering a 3 litre version of the XJ13 indicates it wasn't this rule change alone that would have prevented them racing. England's other comments in the same memo give an indication of the real reason development of the XJ13 was shelved:

In other words, reading between the lines, not only would development of a competitive car be very expensive, it would also have to compete against the equivalent of then-current Formula 1 cars. It would have seemed very unlikely that Jaguar could have triumphed under those circumstances. Finances, since the BMC takeover, were tight and Lyons' emphasis would have been on new production models - not racing - especially not where Jaguar would stand little chance of winning.

The decision was made - late in 1967 - to stop active development of the XJ13 and emphasis switched to a V12 engine for the future lineup of road cars.

It is interesting to see what might have been if a 3-litre version of the XJ13 had been developed. Would it have been along the lines of one of Malcolm Sayer's drawings from around that time?

3 litre successor to the XJ13?

noun. Zeit·geist

… is a German word. Zeit meaning “time” and Geist meaning “ghost,” Zeitgeist means the spirit of the age or times.

Original 1966 XJ13 - MIRA 1971

The 1966 Jaguar XJ13 is no more.

Its spirit and identity live on in a Jaguar-built replica constructed from the mortal remains of the original car which suffered a calamitous crash during a demo run in 1971.

The event was a promotional exercise to publicise the soon-to-be-launched Jaguar Series 3 V12 E-Type. The venue was the high-speed banked track at the British Motor Industry Research Association (MIRA). The date was 20th January 1971.

In the words of Norman Dewis , Jaguar Test Driver, in his book "Developing the Legend

" ... "It was all the fault of the Series 3 E-Type and the new Hassan/Baily 'flat-head' production V12. The idea emerged that the new Jaguar V12 engine in the Series 3 E-Type should be launched to the press at Geneva in March 1971 amid the sight and sound of a previously unrevealed, mid-engined V12 Le Mans car emerging into sight from behind the trees. This involved getting the XJ13 out of hibernation, and as a backup to the press launch, a film would be made for wider distribution."

So it was that on 20 January 1971 a film crew from London met up with the XJ13 and Norman at MIRA.

XJ13 awoken from hibernation before that day in January 1971 Photo © Jaguar Daimler Heritage Trust

After being under wraps for over two years, the car had needed a complete check-over and, as the wheels it was on had done most of the development work, they were substituted by new wheels and tyres which had remained in the stores.”

Photo © Jaguar Daimler Heritage Trust

Break during filming Photo © Jaguar Daimler Heritage Trust

All went well at first, with a good number of laps put in at modest speeds for filming. “

“All went well at first …” Photo © Jaguar Daimler Heritage Trust

Then to conclude”, Norman relates, “I was asked if I could do four fast laps. I did three, and they were quite quick, although not as quick as I had gone in testing.”

"Then on the third lap I came onto the banking, which was the one opposite the tunnel banking where the film crew were, at about 135, and gave it full throttle to hold it in as usual. About two thirds of the way round the banking, the car lurched to the right and almost instantly went into the safety fence ..."

“... the car somersaulted off the track into the muddy field ... tyre tracks showed how the car had almost left the banked section ... then spun down the banking to end up in the field ...”

“ I was asked if I could do four fast laps. I did three, and they were quite quick ..” Photo © Jaguar Daimler Heritage Trust

The XJ13 Log Book simply states "20.1.71 Written off" at the top of the entry ..

Extract from XJ13 Log Book © Jaguar Daimler Heritage Trust

Luckily, the driving skills and lightning reflexes of the Jaguar test driver Norman Dewis meant that he survived the crash unscathed. He walked away from the crash having buried himself in the narrow confines of the cockpit. The state of the car was, however, a different matter …

The fact that the car survived at all to participate in this promotional exercise after development had ceased in 1967, was simply down to the fact that the Jaguar management felt it could play some part in promoting their production V12 engine. A memo from the late Lofty England to the late William Heynes in the September of 1967 outlines the reasons for shelving the XJ13 project as well as the justification for keeping the car in storage and not breaking it up as was the fate for many earlier projects.

“… we are about to commit ourselves for considerable expenditure with ZF for the supply of special gearbox units for the current XJ13 5-litre competition car and also a 3-litre version, which is a new project.

I feel I should point out that there now seems no doubt that the 3-litre maximum engine capacity formula for Group 6 Prototype cars will be applied to all sports car championship races, which includes Le Mans, for the next three years, i.e. up to and including 1970, which period coincides with the remaining period of the current Formula 1 racing car regulations.

There does not, therefore, appear to be any point in doing any further development work on the 5-litre car or, in fact, on a 3-litre version, unless it is our intention to produce a lightweight 3-litre Formula 1 type engine, as cars which will be competing in sports car championship races in the next three years will be in effect Formula 1 racing cars with bodywork to meet the sports car regulations. These regulations may well be amended in 1969, whereby it will no longer be necessary to provide a spare wheel or luggage accommodation, or have a specified windscreen height on open cars.

I suggest we ought to keep the 5-litre competition car as a complete unit, since we could possibly get some publicity value from it when we announce one of our production cars with a 12-cylinder engine.”

What caused the crash?

Norman Dewis confirmed that new wheels and tyres were added prior to filming. The XJ13 Log Book states these wheels were made new after testing of the car only four years earlier (late in 1967). Excepting possible manufacturing defects, it is perhaps unlikely that they could have deteriorated to the point of failure in that short space of time in storage? The use of magnesium as a constituent of alloy wheels was not a new technology in the 1960’s – indeed, magnesium wheels were used on every car that won the Indy 500 from 1946 to 1963.

When the tyres were fitted to the car’s new wheels in 1967, they were fitted without the benefit of inner-tubes. It is possible that the new tyres fitted before filming in 1971 were also fitted without inner-tubes. This, in itself, should not have caused a tyre failure. A more likely culprit may have been the unsubstantiated rumour that a rear tyre was “plugged” to prevent a slow leak before the final high-speed laps?

It is believed that the incident occurred at a speed below those attained during the short period of the car’s active development – although the speed may have been well in excess of 135mph it is unlikely the accident could have been caused by “lifting” or other “aerodynamic” reasons.

Another possibility could have been failure of a rear radius arm. Using the engine block as a stressed member, the rear wheels were mounted by a driveshaft (as upper link), a fabricated lower link and two forward-facing radius arms fixing directly to the engine mounting block. This was a rather innovative solution for the mid-1960s. Examination of the wreckage revealed a damaged upper radius rod on the rear right-hand side (offside)6. However, this damage could have been sustained during the impact. If not, a failure such as this could explain why the car “lurched to the right” before making contact with the safety-fencing at the top of the banking.

Perhaps the true facts and cause of the crash will never be known – the important facts are that the driver, the legendary Norman Dewis, and the car both survived.

What was the extent of the damage?

Except for occasional snippets of information, relatively little information has previously been made available on the development history of the XJ13 – this “vacuum” has been filled by a host of commentators/enthusiasts over the years with a range of statements and opinions – some of whom have probably never even seen the original car least of all been involved with Jaguar! As a consequence of this, an almost “mythical” status has been attached to the car. One therefore has to be careful when sifting through the “established facts”. Fortunately, at least one piece of original documentary evidence survives in Jaguar’s archive and that is the “XJ13 Log Book”. This book gives an account of the development and testing of the car including details of its post-crash examination. This document can be supplemented and cross-referenced, not only with other original surviving records, but by information from known and respected authors such as Paul Skilleter, Philip Porter, Andrew Whyte as well as surviving ex-Jaguar participants such as Peter Wilson, Mike Kimberley, Norman Dewis etc.

The XJ13 Log Book simply states "20.1.71 Written off" at the top of the entry ..

Extract from XJ13 Log Book © Jaguar Daimler Heritage Trust

In the words of Paul Skilleter in 1975 , “… there wasn’t a straight panel left on the XJ13 – a more written-off looking racing car you couldn’t imagine. It was a crestfallen party that took the remains back to Browns Lane and pushed it back into its dark corner of the development department.”

Back at Browns Lane the car was later stripped by G Gardner to assess the extent of the damage. It does seem that the damage was not as extensive as first appeared. Suspension and steering was relatively unscathed with the notable exception of the upper offside rear radius arm. Major mechanical components such as engine and ZF transaxle also survived with the only significant damage in that area being the transmission oil cooler brackets (fitted above the transaxle). However, Norman Dewis confirmed in his autobiography that the car had glanced a sand-filled oil drum as it spun towards the MIRA infield. The impact was in the offside cockpit area (the driver’s side) and Dewis’ helmet was damaged when the windscreen pillar made contact with the oil drum and hit it. This contact was further compounded by a series of end-over-end and sideways rolls.

Damage to the body/monocoque structure was extensive and these sections were beyond economical repair. The body structure of the XJ13 is entirely monocoque consisting of two wide sills (containing fuel tank-bags) which run from front to rear wheels. Between the two sills is a section of stressed floor and three bulkhead sections – two at the front and one immediately behind the driver. A further boxed section forms part of the rear bulkhead and serves to connect the sills at the rear . This entire body structure needed renewal – doors and windscreen surround included.

The two front wheels were found to be OK but both rears were broken. Incidentally, this may support the argument that a broken wheel may have been a consequence of the crash and not a cause?

What was changed during the car’s 1972/73 rebuild?

The car remained in its sorry state for more than a year. As the time for the launch of the new SOHC V12 production engine loomed, Lofty England decided the car should be restored as a promotional, rather than a competition, vehicle. I feel the car’s new status both permitted and defined changes that were made to it during its rebuild to fulfil its new role. As a consequence, certain cosmetic changes were made that deviated from Malcolm Sayer’s original design.

Ted Loades of Abbey Panels spotted the crashed XJ13 stored at Jaguar and offered that Abbey Panels would rebuild it for £1,000 - “Lofty” England accepted without hesitation ….

Luckily the original wooden bucks/formers had survived. They had been stored outside at Jaguar’s store at Radfords and had escaped the periodic “clean up” that components stored inside were subjected to.

There are many so-called “eyewitness accounts” of the damage suffered by the car and others claiming to have intimate knowledge of exactly what was damaged/replaced during its rebuild. The following represents the facts that I have been able to establish so far (further changes still under investigation):

• Completely new body/monocoque/doors built by Abbey Panels. Some of the critical dimensions were varied slightly – including the overall length and details of the rear section. A major deviation was the addition of “1970’s” wide wheelarches to enable the fitment of wider tyres/wheels. This deviation from the original design was done to improve “strength and appearance”.
• Further stiffening sections were added at the front of the car as evidenced by an additional row of rivets that appeared across the nose of the rebuilt car.
• A different means of attaching the windscreen to the surround was employed.
• The existing wheels were repaired by Jaguar and Sterling Metals. It has been suggested that new wheels were made by machining the outer section of Concord undercarriage wheels but no documentary evidence to support this has yet surfaced.
• The original light alloy radiator was found to be corroded and so a new one was made by modifying a XJ12 saloon item.
• Twin lightweight Lucas batteries were added to replace the original (which had been found to be not quite up to the job).
• The original seats were retained although retrimmed in a different material to original.
• A different style of gear-lever was used as the original had been “mislaid”.
• The car was painted in a different, lighter, shade of British Racing Green.

So … to answer the question posed earlier – “Why recreate the Jaguar XJ13?” 

Because it doesn’t exist in its original form – completely true to Malcolm Sayer’s vision…

Because there is only one car and that car is in the capable hands of Jaguar Heritage. I am unlikely to be allowed to experience the “zeitgeist” of this car and era by driving it at its limit....

Because the chances of the “original” being raced are nil – my dream is to see a recreation of the 1966 car on a racetrack racing against the cars it was designed to compete against - those from Ferrari and Ford in particular. The “original” will never race – a recreation perhaps could?….

You are invited to join me in my quest to recreate the legendary XJ13 - your contributions, support and interest will be welcomed. The journey continues!

As "secret" testing of the XJ13 continued, the car was taken to the Silverstone race circuit for two days in August of 1967 ...

The following quoted text is © Jaguar Daimler Heritage Trust and should not be copied without their permission.

Ninth test August 15th & 16th 1967 - Silverstone

222 miles
Sustained testing at Silverstone over 222 miles and subject to special report by M Kimberley (see later)

After Silverstone tests the car was stripped of its g/box, brakes & suspension units. The entire car being thoroughly checked over for structural failures etc. No deficiencies found in any structure
Distortion tests were carried out on the front vertical link assys and as a result certain stiffener webs were added together with mods to accept the girling caliper and disc
Extensive modifications were carried out to the body to accept tyres size 5.25 10.50 x 15 at the front and 6.50 13.00 x 15 at the rear
New wheels to accept these were drawn and made and are now fitted to the car, less inner tubes
Modification to the 5DS25 ZF gearbox including a new differential assembly with 34.5mm drive shafts replacing the original 29mm shaft which had previously twisted and a more positive method of locking the drive shaft bearings in their housings to eliminate end float. The aluminium end covers being 4.2-1 ratio altered to suit. Cast iron end covers are also available but not fitted at present
The fuel system has been completely re-piped to overcome the possibility of a further failure. The new pipe being wire braided and teflon lined
The car has been received by Lucas to suit the OPUS ignition system and the battery replaced by a standard E-Type one

INTERIM REPORT No.9 BY MJ KIMBERLEY TO WM HEYNES

"RESULTS

Fastest laps
D Hobbs - 1 minute 35.7 secs (110.1 mph)
R Attwood - 1 minute 38.1 secs (107.4 mph)

Ride
Satisfactory and wheel bounce coupling obviated

Handling
Both drivers reported inherent oversteer characteristics. Hobbs indicated rear wheel steer and Attwood roll oversteer
Tyre temperatures showed front outer wheel to be vertical, but rear outer wheel camber changed from positive to negative (at max roll) during testing. Front inner wheel camber was slightly negative, but rear inner wheel camber too negative. Adverse rear wheel camber changes are known to occur (See Report No. SP1/13/1) and new parts are awaited from ZF to rectify this.
Time did not allow the various combinations of springs front to rear to be assessed. It is felt that some improvement could be obtained with respect to 'driver feel' by the use of variations in front to rear roll stiffness ratios etc.
Both drivers complained that tyre adhesion diminished after two to three laps....Straight line running now good.

Brakes
Drivers complained of vibration and lack of deceleration at high speeds. Brake fade was experienced, and pedal movement increased with use.
Generally, the brakes were poor, and efficiency was decreased with use. The drivers lacked confidence in them - both drivers stating that lap times could be reduced by two to three secs with improved brakes.

Engine
Engine performance good after thee plugs changed, due to oiling at start of test

Transmission
As anticipated, 7,700 rpm obtained in 4th gear before Woodcote (D Hobbs), but drivers feel that lower ratio would be an advantage.Misc
Fuel System - Tanks and pickup system satisfactory. High pressure feed pipe to PI metering unit connection leak.
Gear Change - New gate satisfactory although Attwood dropped from 4th to 1st on one occasion - interlock mechanism to be checked.
Steering Wheel - Rim section diameter requires increasing.

CONCLUSIONS IN GREATER DETAIL
Although time was not available to utilise the variations in tyre secions, spring rates etc in order to obtain improved ride and handling, and reduce lap times, lack of confidence in the braking system was a severe handicap. The brake system is being stripped and temperature traces analysed to determine reasons for deterioration during running.
Rear wheel steer and uncontrolled camber change can be obviated as soon as parts are available. From the tyre temperatures shown on the data sheet, it can be seen that uncontrolled camber changes occurred at the rear wheels. Without these, the design objective od an upright rear wheel at maximum lateral G would have been obtained at the rear as well as the front. D Hobbs reported that coming out of Chapel Curve with 'tail out' attitude the car 'flicked' to the straight-ahead position. This was confirmed by the reports of two observers.
Tyres were not suitable, but Dunlop will have new tyres shortly in improved mixes, however, in the meantime, it would be most useful to try alternative makes to obtain comparisons. Wheel rim sections are very restrictive on this car and considerable improvement would be obtained with an increase of 1 1/2".

A reduction in lap times could be achieved by ...
Improved brakes ... 2 to 3 secs
Lower CW&P ... 1/2 to 1 sec
Increasing cornering ability with improved tyres and location of wheel ... 2 secs

Although this brings the lap time down to approx 1 min 30 secs the power weight ratio of the car will need to be improved considerably. Comparable power weight ratios:-
Ferrari P4 - 0.210 bhp per lb weight
Lola Chev - 0.207
Ford Mk4 - 0.206
XJ13 - 0.177

The car in its present form is much heavier than necessary and hence the power weight ratio can be improved considerably.

It is noticeable that the driver's comments regarding handling varied considerably between MIRA and Silverstone, thus indicating that the development of a car of this potential is best carried out at a suitable circuit. However, it could be conversely argued that the 'D'Type whilst winning Le Mans, never performed well at Silverstone.

INVESTIGATION RESULTS

Investigation revealed the following major points. For full details see report by E Brookes.

Brakes
The wrong master cylinders were fitted and pedal loads would have been impossibly high (280 lbs for a 1G stop). A large piece of aluminium was located behind the recuperation seal giving intermittent failure of the front brake system.
Although the DS11 brake pads were badly flaked, tapered and distorted, this would be due in part to the above mentioned system faults. Mintex M48 and Ferodo 2429F pads will be available as alternatives for future tests.
Two fractures were discovered in the pedal box but these were not detrimental to the operation of the system.

Tyres
Although D15 tyres were requested and supposedly supplied, it has since been discovered that the rear 5.75 - 1200 x 15 tyres were non D15, thus reducing lateral stability. Dowty Vibrator showed 3.8 c/sec side shake frequency with non D15 5.75's compared to 4.7 c/sec using 7.00 Mx15 D15 - and increasing 'flat tyre' feel remarked upon by D Hobbs.

Transmission
The 29mm spline drive shafts were on the point of failure and the location bearing outer race thrust washer indented. This condition increased lateral 'float' and uncontrolled camber change.

Hubs
The front hub outer bearings were also on the point of failure, due, according to the Timken and Shell Service Engineers, to pre-load. Hubs now to be reset with .002" end float. Dr Tait's calculations confirmed the above engineers' reports."

On Friday, 22nd January I attended a signing of a limited-edition print of this original painting by the artist Nicholas Watts:

Nicholas' superb painting of the XJ13 at speed on the banking has been reproduced as a limited-edition of 150 high-quality, giclee prints. They will soon be available for retail sale (contact Trevor Wilson of TWR Replicas for details).

Following a rendezvous around the XJ13 on display at the Jaguar Daimler Heritage Trust's museum at Coventry, the signing took place in the JDHT boardroom.

The event was organised by Trevor Wilson of TWR Replicas - suppliers of the XJ13 replica in the UK. Each print was signed by Norman Dewis (Jaguar test-driver), Mike Kimberley (current CEO of Lotus and a member of the XJ13 design team), Peter Wilson (author of "Cat out of the Bag" and also a design team member) and Peter Jones (design team member).

Left to right .... Peter Wilson, Peter Jones, Mike Kimberley, Norman Dewis

Norman Dewis

In a career spanning 33 years at Jaguar, Norman Dewis tested and developed a remarkable series of cars including:C-type, D-type, XK 140/150, 2.4/3.4 and Mk 2 saloons, Mk VII/Mk VIIM, E-type, XJ13, XJ/XJ-S and XJ40. Plus, he rode with Stirling Moss in a C-type in the 1952 Mille Miglia, drove a 190mph works D-type in the highly dramatic 1955 Le Mans, raced in the Goodwood 9 Hours, and set an amazing 173mph production car record at Jabbeke in Belgium with an XK 120. Completing over a million test miles at 100mph-plus average, Norman also played a crucial role developing the revolutionary Dunlop disc brake, and survived high-speed crashes and rollovers in the days before seat-belts – and without ever breaking a single bone.

Mike Kimberley

Michael J. Kimberley (“Mike”) C.Eng., F.I. Mech. E., F.R.S.A., F.I.E.D, F.I.M.I has had a remarkable career in the motor industry over the last 56 years, working with some of the great engineers, innovators and leaders of the worlds motor companies. Mike started as an apprentice with Jaguar in 1953 before rapidly progressing to becoming in Section Leader, Special Projects at Jaguar in 1965 where he lead the team developing the Jaguar XJ13 Le Mans car, under such famous names as Jaguar founder Sir William Lyons and Jaguar race director Frank (Lofty) England. In 1969, he joined Lotus as Manager of Continuous Engineering, with the Lotus Europa Twin Cam being one of his most notable projects. Mike rose steadily but rapidly through the Lotus ranks, joining the Board of Lotus aged 37, and becoming Managing Director of Lotus Cars in 1976 and Managing Director of Lotus Engineering by 1980, being responsible for such Lotus icons as the Esprit, Eclat and Elite.

During the 1970s and 80s, Mike had the unique experience of having worked closely with the company’s founder Colin Chapman, with whom Mike set up the world class Lotus Engineering consultancy to enable Lotus to work for many other cars companies around the world. Lotus Engineering is now a globally recognised high technology engineering consultancy and serves many of the world’s car companies. After Colin Chapman’s tragic and untimely death in 1982, Mike became C.E.O of Group Lotus plc, as well as holding board positions with a number of Lotus associated companies such as Chairman of Millbrook Proving Ground and President of Moog Systems Inc. With Lotus under General Motors ownership, Mike became Chairman of Group Lotus plc before leaving Lotus in 1992 to become Executive Vice President (General Motors Overseas Corporation) based in South East Asia. Two years later, Mike became director of the Vector Aeromotive Corporation, and in 1994, he became President & Managing Director of Automobili Lamborghini S.p.A, being responsible for the rebuilding of Lamborghini after Chrysler’s ownership and prior to its sale to Audi AG, as part of the VW Group. In the mid 1990s, Mike left Lamborghini and worked directly for Tommy Suharto as a board member of Timor Putra Nasional (owners of Lamborghini) until retiring with an undiagnosed tropical fever. Returning to the automotive industry a few months later, Mike worked in a consultancy role for a number of organisations including Tata Motors Ltd. In August 2005 Mike was appointed to the Lotus Group International Limited and Group Lotus plc Boards as well as other Boards of Proton. He was appointed acting Chief Executive Officer of Group Lotus plc in May 2006, confirmed as Chief Executive Officer of Group Lotus plc in September 2006. During his second tenure at Lotus, Mike has been responsible for the creation and execution of a new 5 year strategic business plan, and the new, already award-winning Lotus Evora is the first of the range of new Lotus cars to be designed, developed, manufactured and sold by Britain’s most iconic and innovative sportscar company. Lotus Engineering has expanded to become a world-class consultancy employing over 500 highly qualified engineers in five technical centres around the globe. It is revered for innovation, outstanding driving dynamics, exciting niche vehicles and efficient performance engineering. Mike (70) is married with 3 children and 3 grand children and lives in Norwich.

Peter Wilson

Peter Wilson began his career at a small Carlisle garage but in 1961 embarked on an engineering apprenticeship at Jaguar. Within two years he had progressed to the company’s competition department where for over five years he was involved in a multitude of exciting projects - E2A, the new works competition car * The Mk 2 GT saloon * the four-seater E-type * the E-type goes racing * the Mk X convention * building the lightweight E-type * E2A and Maxaret brakes * the 2+2 E-type * the Cunningham Le Mans E-type * Bob Blake and the S-type * * the Coombs power boat * racing 4 WPD * E-type works tuning booklet * XJ13. Peter knew many of the Jaguar ‘giants’ including Bill Heynes, Malcolm Sayer, Bob Blake and Harry Mundy.