Introducing the tera®

Introducing the tera®, Building The Legend Limited’s own unique quad-cam V12 engine. The type of power unit which could have been heard howling down the Mulsanne Straight at Le Mans in 1966 and beyond.


A beautifully sculptural engine and unashamedly “of the period”. Designed to be seen and with a purposeful beauty hinting at the power lying within.

The tera® draws inspiration from Claude Baily’s (former Chief Designer, Jaguar) legendary quad-cam racing engine – an engine designed to power the sublime 1966 XJ13 Le Mans Prototype and return Jaguar to its glory days of Le Mans triumphs and domination. Sadly, the XJ13 was destined to never turn a wheel in anger and the potential of its mighty power-unit was never fully realised. Instead, Jaguar re-designed Baily’s racing engine into a SOHC version more suited for road-use in their rather more sedate road cars.

Building The Legend, XJ13, Neville Swales, Jaguar, LM69, Ecurie Cars
Introducing the tera-™, Building The Legend Limited’s own unique quad-cam V12 engine

Sadly, the XJ13 was destined to never turn a wheel in anger and the potential of Baily’s mighty power-unit was never fully realised. Instead, Jaguar re-designed Baily’s racing engine into a SOHC version more suited to sedate applications.

In the words of Jaguar’s Walter “Wally” Hassan …

“… Between 1949 and 1957 Jaguar were actively involved in motor racing in order to create the sporting image for their cars. Amongst their successes were the winning of the Le Mans 24 Hour Race in the years of 1951, 1953, 1955, 1956 & 1957 as well as Sebring and many other international races and rallies. These cars were powered by the six-cylinder XK twin-cam engine and it was thought to be desirable to develop a successor to compete in future races, particularly Le Mans …. in order to provide the maximum potential in power, a 12 cylinder ‘Vee’ configuration … was conceived to provide for safe running at 8000-8500 rpm. By way of comparison the 6 cylinder twin cam XK engine had been designed without racing in mind.

… during the development period it was decided to withdraw from racing and these policy changes eliminated the need for a competition engine and emphasis shifted to the production (SOHC) version.”

tera®

Drawing inspiration from Baily’s V12 and other classic racing engines of the period, Building The Legend’s tera ® represents an evolution of Baily’s concept. A “what might have been”. An engine born to race but whose potential was never fully realised – until now …

The engine is of course normally-aspirated and drivers of these cars will gain the full visceral experience of a howling V12 race-engine. Distributor-less with choice of period Lucas Mechanical or Electronic Fuel injection. Safe running rev-limit of 8,000 to 8,500 rpm. Available from street-spec to full-race. Applications of this engine are limited only by your imagination!

Building the Legend can upgrade your Classic Jaguar! From a “refresh”, engine-swap, full-restoration and everything in between.

Public launch:

To hear more about it, why not come and visit us at Race Retro on stand 2-136 21-23 February 2020 | Stoneleigh Park, Coventry

For further information visit: www.BuildingTheLegend.co.uk

Engine Specifications:

  • Capacity:         6.1 L (372 cu in); 6.8 L (415 cu in)
  • Bore x Stroke:  96 x 70 mm (3.8” x 2.8”); 96 x 78.5 mm (3.8” x 3.1”)
  • Power:             250 – 650 hp   (261 – 485 kW)
  • Torque:            300 – 600 lb ft (407 – 813 Nm)
  • Compression:  11.7:1
  • 2-valve, over-square architecture, duplex-chain-driven cams with convenient Vernier adjustment.

Contact details:

For details of pricing, specifications, applications and delivery, please contact:

Neville Swales

Building the Legend

Telephone:      +44791 644 5253

Email:              neville@buildingthelegend.co.uk

Transform your Classic Jaguar.

tera®

“to the power of 12”

from the Greek – “teras” = monster.

Contact us for details https://buildingthelegend.co.uk/make-contact

Looking back to 2015

Building The Legend, XJ13, Neville Swales, Jaguar, LM69, Ecurie Cars

The year is now 2015 and my car is approaching its “rolling chassis” stage – mirroring events of 50 years ago in Jaguar’s Competition Department. It was then 1965 and William Heynes, Jaguar’s Engineering Director still had hopes of seeing the car on track to contest that year’s Le Mans endurance race. Time was short but the skilled team working behind closed doors were used to working to such tight deadlines …

Jaguar XJ12 - Building The Legend
Jaguar XJ12 - Building The Legend
Jaguar XJ12 - Building The Legend
Jaguar XJ12 - Building The Legend

Let us go back a few years …

1963.

William (“Bill”) Heynes, Jaguar’s Engineering Director takes note of a change to the Le Mans regulations which now open the door to sports/racing prototypes of up to 5.0 litres (305 cu in) in capacity. No doubt, he smiled to himself as he was now in a position to bring a plan he had long kept in the back of his mind to the fore …

Jaguar XJ12 - Building The Legend - William Heynes
William Heynes of Jaguar

For Bill Heynes, racing engines had always been in his blood. Having left Humber in 1935 where he completed his engineering apprenticeship, Heynes joined William Lyons at SS Cars. Six months later he was working closely with and became one of the prime architects of an overhead-valve conversion for the Standard 6-cylinder engine. The first cars to have this engine installed were known as SS Jaguars. One of these first cars was the SS Jaguar 100. The power unit Heynes had a hand in designing soon powered this car to best performance in the 1936 Alpine Trial – showing these cars were more than just pretty faces.

Ten years later, Bill Heynes combined his talents with Harry Weslake, Walter Hassan and Claude Baily to produce Jaguar’s legendary and long-lived 6-cylinder XK engine – an engine which was to bring Jaguar success, not only in the showroom, but also in the highest-level of competition. Cars powered by these engines still dominate fields in historic racing today. After successes in the 1950s at La Sarthe with the works C-Types and D-Types, Jaguar switched their efforts to road cars and formally retired from racing in 1956 (although the factory continued to support private entrants).

Jaguar XJ12 - Building The Legend
Left to right: Walter Hassan, William Heynes and Claud Baily of Jaguar

Heynes did not disband Jaguar’s Competition Department and ensured its personnel remained intact after 1956. Key amongst these personnel were Malcolm Sayer who had masterminded the design of the highly-successful C-Type, D-Type and the E-Type prototypes. Another member of this select team was the South African Derrick Whyte, a talented chassis engineer who had cut his teeth at Connaught and became associated with their well-engineered, beautifully-built and superbly-handling cars. The third member of the team was Alex Frick whose expertise lay in tubular chassis frame design.

By 1963 Jaguar were on the brink of a return to racing with their Lightweight E-Types. However, the change in regulations for Le Mans in 1963 meant these beautiful cars would have been completely overwhelmed by the 5-litre prototypes now allowed by the regulations. The way was clear for Bill Heynes to carry out his plan for a full assault at Le Mans with a new mid-engined prototype sports car powered by Jaguar’s own 5-litre quad-cam V12 – an engine which was first and foremost aimed at racing with a possible secondary use in one of Jaguar’s future road cars. Unlike the XK 6-cylinder engine which was aimed fairly and squarely at road use and later modified for racing.

On 9th July 1965, Heynes despatched a young Mike Kimberley to Silverstone to see what he could learn. His brief? To brush up on the latest in Sports Racing Car design to see what the others were doing.

Fast-forward …..

The story and fate of Jaguar’s car designed to carry out this assault at Le Mans is now well-known.

In short …

Only one car was built and circumstances conspired to prevent the car from ever turning a wheel in anger. Construction began in 1965 and the sole example built was completed in 1966. Its breaking of the UK closed-lap circuit record in 1967 in the hands of its main Test & Development Driver David Hobbs, showed its potential. This record was to stand until 1999 until beaten by a McLaren F1 road car.

Many myths and stories have been built up around this legendary car over the years. In recent years, exhaustive and comprehensive research by respected author Peter Wilson has established the facts surrounding this car – research which has been substantiated by interviews of those who were there as well as a mass of surviving contemporary documents and reports. Peter’s book “XJ13 – The definitive story of the Jaguar Le Mans car and the engine that powered it” provides a definitive record and builds on earlier writings from Jaguar historians such as Andrew WhytePaul SkilleterBernard ViartMichael Cognet and Philip Porter.

The car underwent a series of clandestine but official tests arranged by its Project Manager Mike Kimberley (later to become CEO of Lotus Cars). Professional race-driver David Hobbs piloted the car in all official tests, supported by Norman Dewis and Richard Attwood. The one-and-only original was put under wraps in 1967 where it remained until 1971 when it was wheeled out to help publicise the forthcoming Series 3 V12 E-Type. The sad fate of the car in the hands of Norman Dewis is now well-documented. The car was crashed and its mostly-intact underlying structure was clothed in a new body fashioned by skilled craftsmen at Abbey Panels.

The sublimely beautiful lines of Sayer’s masterpiece were altered during the rebuild and the car remains in this altered form to this day. Regularly displayed at prestigious events the car forms a backdrop to Jaguar’s rich heritage and testament to the genius of Malcolm Sayer.

Many replicas of Jaguar’s current car exist although none have yet come close to capturing Sayer’s original 1966 form. Jaguar’s one-and-only altered original was digitally scanned recently and the resultant body is being applied to a GT40-inspired chassis which contains parts of an engine which, although never installed in a car in period, does contain surviving original prototype quad-cam components. This car, however, replicates the car as it stands today with its many differences to the 1966 original.

In 2010, I acquired the only surviving complete original prototype quad-cam V12 built to a specification similar to that of the engine which powered the original car in 1966. Four years of exhaustive and painstaking research have resulted in the accumulation of original and unique data for Jaguar’s original 1966 masterpiece.

What to do with this engine and all this data?

What would YOU do?

CONSTRUCTION BEGINS

First of all, the following must be emphasised:

There is, and always has been, one Jaguar XJ13. The car is owned by the Jaguar Daimler Heritage Trust. Undoubtedly, their car is unique and has continuous history linking it back to the one and only original. It may have been described as a, Jaguar-built replicaby authors Viart & Cognet in their 1985 book, “Jaguar – A Tradition of Sports Cars” (page 318), with forward by William Lyons himself, but this may be a little unfair as most of the underlying structure was salvaged and re-used. The engine installed in the car today is a different engine to the one originally installed in the XJ13 in the Spring of 1966 but it remains one of the very few prototype quad-cam engines that have survived and was installed in the car in period. OK, the body may be completely new, and different in some respects to the original body, but there can be no doubt that the car gracing the Jaguar Heritage collection can describe itself as the unique Jaguar XJ13.

What Neville is attempting to create can only ever be a facsimile and homage to the original XJ13 and its designer Malcolm Sayer. There is, and always has been, ONE Jaguar XJ13.

Four years of painstaking research – supplemented by interviews with those who were present at the time – resulted in a collection of data which could be used to precisely define the geometry and form of the original 1966 car. Having exhausted information available in Jaguar Heritage’s own archive, additional information was unearthed from records, photographs, reports as well as documentation passed down through the families of surviving relatives. This accumulated mass of data was combined by Neville using computer-aided design techniques to arrive at a digital model of the car and its underlying structure. This data includes the precise location of key mechanical and body components as well as suspension geometry as measured in 1966. The hope is that the finished recreation will duplicate the driving experience and characteristics of the original.

The prospect of actually driving the car under its own power for the first time is something which keeps me awake at night … 🙂

My aim, from the outset, was to attempt to replicate not only the original car but also to follow the build sequence as carried out by Jaguar in their Competition Department. As time went on, both myself and the people entrusted with the build of his recreation came to respect the skills of the original builders more and more. Without doubt, today’s use of computers and rapid-prototyping does make life easier. Wheras I was able to digitally model and “trial-fit” virtual components and body panels on a computer screen, these techniques weren’t available in 1964 and the builders of the original made do with “trial and error” as well as experience born from years of mastery of their craft.

In September of 1964, although there had been no official “go-ahead”, Bob Blake assisted by Geoff Joyce andRoger Shelbourne set about translating Malcolm Sayer’s hand-written data into wooden “buck” which could be used to shape the outer body skin.

Jaguar XJ12 - Building The Legend
Photo taken during the crashed car’s rebuild in 1972/73 showing the original rear body buck in the foreground.

The bucks (two in total – front and rear) were to be sent to Abbey Panels who would form the outer skins leaving Jaguar to fabricate the car’s monocoque/chassis. All they needed now was the formal go-ahead.

I followed a similar process – translating 3D data (and data derived from original technical drawings and photographs) into a “virtual” wooden buck which could be used to shape the outer body skin of my recreation. I was assisted in this process by CAD/3D specialists. Considerable work was needed by the skilled team at my chosen bodyshop to remedy shortcomings in the supplied buck and to ensure faithfulness to the original car but we eventually ended up with something which could be used in the real world! To ensure accurate replication of details such as headlamp apertures, air scoops and windscreen surround, parts of the wooden buck had incorporated solid 3D sections which would be used as “hammer formers”. At this stage, the wooden buck only existed on a computer screen.


©Neville Swales – Digital representation of full-size body buck (third-scale model in foreground). Looks “pretty” but this is only a digital representation needing considerable work by skilled artisans for its use in “the real world”.
©Neville Swales – Close-up of actual buck.
©Neville Swales – Hammer-form nose-cone and headlamp 3D sections.
©Neville Swales – Nose-cone 3D section being CNC machined

Before this virtual buck was turned into reality, I digitally replicated the XJ13’s underlying chassis/monocoque and was able to virtually “trial fit” the body onto it to ensure everything was as it should be.

©Neville Swales – Trial-fitting virtual components
©Neville Swales – Trial-fitting virtual components

I was also able to add suspension components, engine, wheels and tyres etc to ensure everything would fit together without fouling when the digital model became reality. At this stage, it was possible to view the model from every possible angle as well as estimate things like final weight distribution, centre of gravity and the way light would catch the finished body surfaces. These are all things unavailable to Jaguar in 1964 and, instead, would have relied on trial-and-error as well as pure skill. The original builders were truly craftsmen.

Something which certainly wasn’t available to Jaguar in 1964 was the ability to print small-scale 3D models of the body before committing to buck manufacture. It is all very well being able to see things on a computer screen but being a bit “old school”, I didn’t feel comfortable giving the go-ahead to manufacture a full-size buck until I had something I could hold in my hand. Something which could be held and, in theory, be painted so the way it caught the light could be studied. I therefore commissioned a number of small-scale 3D-printed models to give himself greater confidence in the accuracy of the final body. 1/3rd and 1/6th bucks were also produced to show details which may not have been apparent at a smaller scale. These small-scale models did show some shortcomings in the digital data arrived at by my chosen 3D specialist and some manipulation of the data was required to arrive at something more satisfactory. I do recommend the use of 3D-printed models if you are considering taking the same path because things which can look “pretty” on the screen do not always translate ideally into “the real world”. It always helps to have something you can hold in your hand!

Finally, reasonably satisfied with the accuracy of the model, I gave the go-ahead for a full-size buck to be made directly from the CAD data – knowing that it could only represent a “guide” and the skills of the bodyshop would overcome any shortcomings. My faith in the skills of my chosen bodyshop proved to be well-founded.

Meanwhile, back at Jaguar, there was still no formal “go ahead” for the outer body skin to be made by Abbey Panels. The Competition Department staff knew that, if the car was going to be ready for the 1965 Le Mans, they really needed to get on with it. Derrick White pressed Bill Heynes but was told “not yet”. First signs of a lack of urgency around the project were becoming evident. Sadly, knowing what we do now, the best chance of a win at Le Mans would have been in 1965 – before Ford’s GT40 had got into its stride leaving Ferrari as the only serious competition.

As Peter Wilson reports in his book, “XJ13 – The definitive story of the Jaguar Le Mans car and the engine that powered it”,

“… as the surface plate we had in the Competition Department was not large enough, or indeed remotely suitable, Bob Blake, Geoff and Roger constructed a very rigid wooden platform on which to build the monocoque. This consisted of a cross-braced perimeter frame constructed from 9 x 3” timber, topped with ¾ inch thick plywood sheet. It was marked out with ’10 lines’ – lines 10 inches apart, either side of the longitudinal centreline, along the length of the platformand similarly in the transverse direction, from the front ‘zero’ datum point (the centreline of the front wheels). This would enable accurate referencing of each of the myriad of construction reference points defined by Malcom Sayer’s drawings.”

As a further means of ensuring accuracy of the replica monocoque, I turned to his computer again and commissioned a “monocoque buck” based on these reference points which would be precisely located in relation to the ’10 lines’. The originally supplied monocoque buck proved not to be fit for purpose and I commissioned a further buck to ensure faithfulness to the original.

©Neville Swales – Monocoque buck showing ’10 lines’ on baseboard

My chosen bodybuilders, used this monocoque buck to fabricate and build the front and rear suspension sections. We designed his own jigs to precisely locate all suspension components consistent with Jaguar’s original data.

Back in the January of 1965, Bob Blake made a start on the monocoque. At the time, it was believed that it was still possible to have the car up and running in time for Le Mans – although time was very, very tight. The hard-working members of the Competition Department were used to these tight deadlines. For example, work had started on the E2A E-Type Prototype in January of 1960. It was ready to run before the end of February and went on to race at Le Mans in June of the same year.

An XJ13 at the 1965 Le Mans was still a possibility.

The monocoque centre section consisted of the floor and outer sills. These were produced in two halves, as mirror-images of each other and joined along the centreline of the car using a double row of 3/16” dome-headed rivets. The sills had internal stiffeners and were roller-welded along their lengths. The Competition Department didn’t possess equipment to do this themselves so the entire assembly was shipped to Abbey Panels so they could be welded there. The welded sill sections were returned to Jaguar where bulkheads and door apertures were added. The team had been added to by that time by Denys Davies who assisted Derrick White with fabrication of detailed suspension components.

©Neville Swales – Original rear monocoque construction detail
©Jaguar Heritage – Original front monocoque construction detail (reproduced with permission)
©Neville Swales – 2013 vs 1965

Determined to exactly replicate the XJ13 monocoque, we decided to fabricate a “prototype” sill structure in steel just “to get it right” before we fabricated the final version using the (rather expensive) original-spec aluminium.

©Neville Swales – Prototype all-steel monocoque on the originally-supplied monocoque buck (later to be replaced by a more accurate and usable item).
©Neville Swales – Prototype all-steel monocoque
©Neville Swales – Trial-fitting of front suspension on steel prototype monocoque
©Neville Swales – Prototype front suspension on steel prototype monocoque
©Neville Swales – Final monocoque – front suspension detail (NB original XJ13 does not have collapsible steering column section)

This steel prototype has since been destroyed and its place taken by the final aluminium version. As with the original, the front suspension consists of a steel framework riveted to the floor and front bulkhead. After many iterations and failed attempts by Derrick White to persuade Bill Heynes to use a state-of-the-art purpose-designed front suspension setup, Heynes prevailed and the XJ13 was fitted with a modified 1964 Lightweight E-Type front suspension as can be seen in the following picture:

©Jaguar Heritage – Front suspension detail – as 1964 Lightweight E-Type (reproduced with permission)

I replicated the front suspension as far as I was able to arrive at the following:

©Neville Swales – Final monocoque – front suspension detail

The words Jaguar, Jaguar XJ13, XJ13 are used in a historical/descriptive context and in no way suggest our recreations/replicas are approved by Jaguar. It is widely known that there was only ever one Jaguar XJ13 and any others can only ever be replicas, facsimilies, tributes, recreations, toolroom copies or similar.

1966 Le Mans – Ford vs Ferrari …. vs Jaguar?

XJ13, Building The Legend, Neville Swales, 1966 Le Mans - Ford vs Ferrari .... vs Jaguar?

Original XJ13 – Would it have been competitive?

In my opinion?

Yes. Let me explain …

How did the competition look?

When I scan through reports, analyses and tests, Jaguar clearly had two cars in its sights – Ferrari’s 330 P3 and Ford’s GT40.

Ferrari P4

In 1964 their eyes will have been on a 1966 Le Mans debut for a team of XJ13s. These cars would have raced as Le Mans Prototypes. 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 GT40

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 first GT40s raced in 1964 and 1965 with no great success. In 1966 however the 7-litre Mk II absolutely dominated the 24 Hours of Le Mans race with a 1-2-3 result – shades of the Jaguar victories in the 1950s. This dominance continued in 1967 with a win by the Mk IV version of the car.The Lucas Mechanical Fuel-injected 1966 Ferrari 330 P3 used a rather fragile transmission that was later replaced by a ZF. Jaguar’s design included Lucas Mechanical Fuel Injection and the more robust ZF DS25-1 transmission from the outset. In 1967 the P3 became the P4. The latter car finished 2nd and 3rd at Le Mans in 1967 behind the winning Ford GT40 Mark IV.

How would the XJ13 have fared against the mighty GT40?

Project delays and lack of commitment by Jaguar meant things got off to a slow start and the car wasn’t completed until 1966. Sadly, the car’s main opportunity to shine at Le Mans may have been missed.Although Jaguar’s rebuilt “original” will probably never race, my car perhaps could. However, even though I can recreate a car with similar power and identical handling characteristics to the 1966 original, it would probably be humbled by a GT40 if it lined up against it on a track today. The reason being that, since 1967, original GT40s have undergone continuing race development and are probably now achieving levels of handling and performance far in excess of those achieved in 1967. The Jaguar XJ13 hasn’t enjoyed the best part of 50 years continuous development and would likely be embarrassed if placed on a track alongside an original GT40 today.This would definitely be true of Jaguar’s one-and-only rebuilt “original” which has led a sheltered life punctuated only by the odd low-speed excursion and short run over the last 50 years since it was rebuilt as a “demo queen”. In performance terms, the engine powering the “original” is only a shadow of its former self and would likely struggle to maintain any sort of pace.

As a lasting homage to the genius of its late designer Malcolm Sayer, Jaguar’s rebuilt “original” does continue to inspire with its superb lines but is likely to remain as no more than an inspiration.

However ….

We can at least examine the many contemporary records and reports that have recently come to light. We are fortunate in being able to re-live events through things such as the detailed development and testing reports recorded at the time. The XJ13 Project Manager, Mike Kimberley fortunately recorded events in detail through his meticulous test reports and worklists that were prompted by post-test analysis. A then-current GT40 was acquired by Jaguar’s Competition Department in 1966 and the results of their findings were also recorded.

In addition ….

Readers of this blog will know of my intention to not only recreate the XJ13 exactly as it was in 1966 but also to eventually see it on a racetrack. I am taking great (some would say “obsessive” ) care to remain true to original suspension design/location so that my recreation should perform similarly to the 1966 original. The finished product may give us additional insight into how the original may have fared in competition. Watch this space!

“Jaguar’s GT40”

By the middle of February 1966, the XJ13 was nearing completion. With all eyes on the likely competition at Le Mans in 1967, “Lofty” England (Jaguar’s racing team manager) succeeded in borrowing a Ford GT40 from Ford Advance Vehicles. It was duly delivered to the Competition Department where it was subjected to a detailed analysis. Mike Kimberley, Derrick White and Malcolm Sayer were very much involved in this analysis of the “competition” and participated in its stripdown, measurement and analysis. Someone else also involved in this analysis was Peter Wilson – author of the definitive work on the XJ13, “XJ13 – The Definitive Story of the Jaguar Le Mans Car and the V12 Engine that Powered it”.

The car Lofty borrowed wasn’t a racer but a road-going version powered by a 4.7 litre wet-sump engine.According to Peter Wilson:“Touring equipment in the form of ‘luggage boxes’ were fitted either side of the engine compartment, adjacent to the exhaust manifolds. We felt these were good for very little else other than keeping one’s fish and chips warm on the way home from the chip shop! This car, road registered OVX 355D, sat on wire wheels and was painted silver, while the cockpit was fully-trimmed and featured a driver’s door mounted, push-button Motorola radio, together with a twin speaker system – sheer luxury on wheels!”Has this car survived? Perhaps any GT40 enthusiasts could please let me know?The car was taken to MIRA on 4th March 1966 by Mike Kimberley & Norman Dewis and the car was put through its paces. Testing wasn’t particularly extensive as the car wasn’t a full race version – in any case, time was running short!In his book, Peter Wilson gives an account of the MIRA test. Bearing in mind Norman Dewis had comparison with the XJ13 in mind, in summary:

  • Despite being a “road car”, the general handling characteristics were very good and the car was responsive with sensitive and positive steering.
  • There was low-speed understeer which only changed to oversteer at maximum power.
  • The car was very susceptible to being blown off course in conditions of changing wind direction – requiring correction to maintain course.
  • Maximum cornering force was just less than 1G.
  • Whilst smooth, even braking could be achieved, it was not possible to lock the wheels. The pads hadn’t been fully warmed for these tests however.
  • The maximum lap speed was found to be 133mph which compared poorly with the D-Type’s 155mph – highlighting the “road-car” spec of this GT40.
  • Even though the car was et up for the road, ride refinement was lacking with a hard ride and “kicks” from the steering.
  • Static geometry checks showed the car had been quite badly set up with a 1″ difference in track front-to-rear (both should have been 54″).
  • The gearchange for the DS25-1 transaxle was found to be light and easy to use (as was the case with the XJ13). I’ll let you know in due course!
  • Pedal spacing was ideal and made “heeling-and-toeing” very easy. The accelerator pedal was a pendant type wheras the XJ13’s was organ type.

After the driving tests, the car was taken into the MIRA wind-tunnel and Malcolm Sayer was able to examine the car’s airflow characteristics in some detail.Sayer noted differences between the car and its racing version including blanking-off of brake ducts and side-cooling ducts. He also noted the rear spoiler was a good 4″ shorter than the 1965 car and the car didn’t have the lift-reduction deflector plates which would have increased drag.Although drag for the road-car was lower than the 1962 E-Type and 1962 Ferrari Berlinetta, it was significantly worse than the 1955 racing D-Type. Aerodynamic lift did seem to be an issue and it was interesting to note that “reliable sources” stated Ford were suffering with excessive lift on their racing versions. These “reliable sources” may have been from MIRA who were carrying out secret air-studies for Ford at the time.It was interesting to see that the XJ13 (which was almost complete at the time these comparisons with the GT40 were carried out) had many similarities to the GT40. Two completely disparate teams of individuals working towards a common goal – success at Le Mans – ended up with very similar solutions. For example:

  • The Ford famously was just over 40″ high wheras the XJ13 was lower at just under 39″
  • Wheelbases were within an inch of each other (Ford 95″; Jaguar 96″)
  • Tracks were similar (Ford 54″; Jaguar 56″)
  • Width (Ford 70″; Jaguar 71″)
  • XJ13 had similar but smaller frontal area (Ford 16.91 sq ft; Jaguar 15.97 sq ft)
  • XJ13 had similar but superior drag (Ford 0.35; Jaguar 0.29)
  • XJ13 was lighter (Ford 2,707 lbs; Jaguar 2,600 lbs)
  • Lower centre of gravity for the XJ13 (Ford 15.02″; Jaguar (14.5″)

XJ13 – Tested at Silverstone

The XJ13’s main test driver was David Hobbs. Although Jaguar already had a competent driver in the shape of Norman Dewis, William Heynes recognised as early as 1964 that a car such as the XJ13 really needed a top-flight race driver to help develop it. There is some evidence to suggest that Jack Brabham had been approached in this respect but, in the end a former Jaguar apprentice – David Hobbs – was recruited for testing. In 1969 Hobbs was included in a FIA list of graded drivers which was an élite group of 27 who were rated the best in the world. It was Hobbs who achieved the unofficial UK closed lap record with the XJ13 which stood for the next 32 years. The XJ13’s main test and development driver, Hobbs, was joined at Silverstone for the XJ13’s final test at full racing speed by another top-flight racing driver (and ex-Jaguar apprentice) Richard (“Dickie”) Attwood.On the morning of Tuesday, 15th August, the XJ13 was taken to Silverstone amidst great secrecy. Mike Kimberley planned for David Hobbs to drive all that day for comprehensive testing under full racing conditions. They wanted to see what the XJ13 could do! Unfortunately, rain began to fall (this was an English Summer after all) and testing was curtailed early on. Conditions looked better the next morning and David Hobbs was joined by Richard Attwood. Although drying, the track was still wet in places and the XJ13 gingerly took to the track. Conditions continued to improve although a shower did interrupt proceedings for two hours and some dampness did remain at the end of testing. Hobbs and Attwood managed a full five hours of testing – although they had to seek shelter for two hours during the shower.Hobbs did outperform Attwood. Mike Kimberley later described Hobbs as “a fearless driver” who clearly drove with maximum commitment. Hobbs had also carried out the lions’ share of testing and so was very familiar with the car already. His best time was a respectable 1 minute 35.7 seconds – this on a drying track with a lingering damp patch at Beckets. A time comparable to Attwood’s previous best time in a Ferrari LM of 1 minute 35 seconds – the same time as the best time for a GT40 in the hands of P. Hawkins (1 minute 35 seconds).The test at Silverstone was to be the final outing for the XJ13. It was never to race and only emerged when required to play a supporting role in a promotional film in 1971 for the soon-to-be-launched Series 3 V12 E-Type. It crashed and was rebuilt in 1972/73 in a specification more suited to its role as “demo” vehicle. It has now been established that the crash was caused by the failure of a rear tyre that had been plugged to cure a slow leak – Norman Dewis having ignored instructions not to drive at racing speeds for the camera.

Would the XJ13 have been competitive at Le Mans?

After the Silverstone test, the data was examined and a package of improvements was proposed which may have delivered the following:

  • Improved brakes – an improvement of 2 to 3 seconds
  • Lower axle ratio – a further 1/2 to 1 second
  • Improved tyres/wider wheels – 2 seconds

The above, conservative, estimates would have resulted in a Silverstone lap time in the region of 1 minute 30 seconds. A full five seconds faster than the best lap time achieved by P Hawkins before 1967 and coincidentally, similar to Hobbs’ best lap time in a BRM V8 F1 car at the British Grand Prix in 1967 at Silverstone.The XJ13 was designed in 1964 by a small team of people under Bill Heynes – Malcolm Sayer, Derrick White and Alex Frick. At the same time, they were working on a number of actively-campaigned E-Types. This team was incredibly small considering their workload (even Connaught had a design staff of 8 in 1955!).In 1964 they settled on a monocoque design using Baily’s quad-cam V12 as a fully-stressed member – like the D- and E-Types before it, a more sophisticated and advanced design than its contemporaries. By the end of 1964 they had settled on the basic layout of the rear suspension. In essence, similar to the E-Type with a lower wishbones and a fixed-length driveshaft acting as upper link. White, argued for a transverse upper suspension link coupled with a sliding driveshaft. This would have ensured greater accuracy in controlling rear wheel geometry when faced by the demands of tyres rapidly growing in width at the time. His wishes were constantly rejected by William Heynes.Derrick White also designed a series of completely novel state-of-the-art front suspension setups. Heynes, it seems, from the outset wanted to adopt an E-Type based setup. Each of White’s designs were rejected by Heynes in turn. He also became increasingly frustrated at Heynes’ lack of progress and stubborn attitude. In the end White became royally pi**ed off with all this and left Jaguar to join Cooper.Shortly after joining Cooper (and having been given free reign to design a car in the way he felt it should be designed) his Cooper-Maserati became a front-runner in the 1966 F1 season then won the first race of the 1967 season. He later joined the Honda/Lola/Surtees consortium and helped design the “Hondola” wich won first time out in 1967.It is a shame he was prevented from exercising his talents on the XJ13 as well as the lack of urgency throughout 1965 as Ford may really have been humbled by the XJ13!

What do you think?

The words Jaguar, Jaguar XJ13, XJ13 are used in a historical/descriptive context and in no way suggest our recreations/replicas are approved by Jaguar. It is widely known that there was only ever one Jaguar XJ13 and any others can only ever be replicas, facsimilies, tributes, recreations, toolroom copies or similar.

Four car tribute to honour Norman Dewis OBE at The Classic Motor Show

Ecurie Cars
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Image: Classic Driver

The Jaguar Enthusiasts’ Club will be paying tribute to legendary Jaguar test development driver, Norman Dewis OBE at the show with the special four-car display (see below), supplied by the Jaguar Daimler Heritage Trust and held at the NEC over the weekend of 8-10th November 2019. They celebrate the story of his Jaguar career alongside an exciting new car from Ecurie Ecosse, the LM69 which represents a contemporary evocation of one the most famous cars Norman Dewis worked on.

Norman Dewis, who passed away in June 2019 at the age of 98, was a hero to Jaguar fans and a friend to many in the classic car community. He was chief test driver and development engineer for Jaguar between 1952 and 1985. That 33-year career with Jaguar saw him break the land speed record for production cars in a Jaguar XK120 on the Jabbeke Highway in Belgium in 1953 and, through his long and often dangerous hours of test driving, significantly contributed to the Le Mans wins for Jaguar in the 1950s with the C and D – Types. Norman also raced alongside the greats which included Moss, Hawthorn and Fangio behind the wheel of a works Jaguar D Type.

Norman’s development career spanned the XK140 and XK150, the Mark 2 saloons, the E Type and the first XJ saloon through to the XJ40. In 2014, the adoration of Norman’s fans was recognised on a national scale, when he was awarded the Order of the British Empire (OBE).

The Jaguar Enthusiasts’ Club, with the support of the Jaguar Daimler Heritage Trust and Ecurie Ecosse, has assembled a line-up of four cars that represent key moments in Norman’s career. The prototype Jaguar D Type, the motor show E -Type that he famously drove through the night to Geneva, the unique XJ13 that he developed and was lucky to escape a crash in – all represent key moments in Norman’s life. Furthermore, the lasting legacy of the development work that Norman put into the XJ13 can be seen with the debut at the show of the new Ecurie Ecosse LM69, based on the original XJ13.

Furthermore, throughout the weekend, the club will share interviews and talks from club members, historians, authors and others who knew Norman, to share memories and stories of the much-admired test driver.

James Blackwell, General Manager of the Jaguar Enthusiasts’ Club says, “Our Jaguar loving community has lost a dear friend, colleague and hero in Norman. His stories captivated and inspired us all in the club and he was wonderful company, a man who never took his foot off the gas. It felt important to everyone in the Jaguar Enthusiasts’ Club to say goodbye to our hero by working with our friends at Jaguar Daimler Heritage Trust, who have supplied this stunning line up of cars. With their help, we will transform our car club display stand at this year’s NEC Lancaster Classic Motor Show with Discovery, into a tribute to Norman’s incredible life.”

“We are really excited to premiere the Ecurie Ecosse LM69 at the show, a stunning new car, guaranteed to create a stir. We felt that the LM69 is a great embodiment of the lasting legacy of Norman’s work on the XJ13 back in the 1960s.”

Norman Dewis OBE was a one of a kind. He came from an era when racing and test drivers alike were heroes. When the boundaries of technology and engineering were pushed aside and broken through, whilst wearing a shirt and tie. Norman was one of the most highly respected drivers and engineers that has ever lived, he had a special talent for assessing the handling of car and how it might be improved. He was tenacious and hard working with an enviable determination to achieve and exceed the goals that Jaguar set for him. The likes of Norman Dewis will never be seen again, so come and join the Jaguar Enthusiasts’ Club at the 2019 Lancaster Classic Motor Show with Discovery to celebrate the life of the friend, hero and inspiration to Jaguar fans everywhere, Norman Dewis OBE.

The cars in detail

Source: Octane Magazine
Jaguar D Type – OVC 501

Source: Octane Magazine

Jaguar D Type – OVC 501
The first car in the line-up will be Jaguar’s prototype D Type, OVC 501 from 1954. This is a truly unique car and is the factory prototype for the machine which brought Jaguar a hat-trick of victories from 1955 to 1957 thanks, in large part, to the development work and testing undertaken by Norman Dewis. Norman put the car through a rigorous programme of tests in which he found problems with the engine, gearbox and steering, all of which were quickly rectified. Capable of 190mph on the circuit, this car was also driveable on the road, which Norman did, as all the works cars were driven from Coventry to Dover, onto the ferry, and then down public roads to the Circuit De La Sarthe, Le Mans.

Source: Jaguar Belgium
Jaguar E Type – 77RW

Jaguar E Type – 77RW
In March 1961, an icon was launched at the Geneva Motor Show, the Jaguar E Type. This car is the subject of one of Norman’s most famous stories. Norman drove it out to Geneva from Coventry, non-stop through the night, to satisfy the unprecedented demand for press test drives at the motor show launch. The epic trip, saw him embark upon a dramatic 12-hour overnight endurance run, making it in time for the launch at 10 am the next morning. 77 RW is now the oldest surviving open E-types and was the car that launched one of the symbols of 1960s motoring. Most recently, the car was the wedding transport for Pippa Middleton’s marriage to James Matthews.

Source: Classic Driver
Jaguar XJ13

Jaguar XJ13
There was only ever one XJ13 ever built and it will be on display as part of the Jaguar Enthusiasts’ Club tribute to Norman Dewis. It was built as a contender to the likes of Ferrari and Ford at Le Mans, but never it raced. XJ13, which was Jaguar’s first mid-engined car, spent four years sitting under covers at the factory after development was canned due to a change in the motor sport regulations. However, in 1971 it was used in a film for the E Type V12 launch, shot at the MIRA test track. Naturally, Norman Dewis was at the wheel, but as he was coming in after filming, the car suffered a puncture on the banking which sent it crashing into the track’s retaining fence. It was a spectacular accident, resulting in Norman flipping end-over-end twice, rolling twice, then landing back on his wheels. Ever the professional and never strapped in, Norman managed to hide under the scuttle and turn off the ignition and as a result, was lucky to survive. He not only escaped unhurt but was also back at work the very next day! The car was later rebuilt and retired to a gentler life.

Source: Design Q
Ecurie Ecosse LM69

Ecurie Ecosse LM69
Fifty years on from the completion of the XJ13, the legacy of the car that Norman helped to develop lives on in the incredibly exciting new LM69, by Ecurie Ecosse. Launched in September, this will be the car’s first ever appearance at the Classic Motor Show held at the NEC Birmingham. Ecurie Ecosse will only be hand-building 25 in Coventry, in keeping with the FIA Homologation requirements of 1969 for running prototypes at Le Mans of over 3000cc. The “Building The Legend” quad-cam V12 is the heart of the car, designed to evoke the experience of driving at Le Mans. However, unlike the original XJ13 – this is fully road legal. Ecurie Ecosse have developed the car to a strict and unique brief which saw them adhering to the regulations of 1969, featuring only design details and technology that entered motorsport at that time. Composite materials have been used, it’s lighter than the original XJ13 and it boasts experimental aerodynamic devices, wider wheels and a multitude of engine improvements. This is a great opportunity to see this new, exciting car that celebrates the legacy of the XJ13 and the work of Norman Dewis for modern times on the Jaguar Enthusiasts’ Club stand.


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The words Jaguar, Jaguar XJ13, XJ13 are used in a historical/descriptive context and in no way suggest our recreations/replicas are approved by Jaguar. It is widely known that there was only ever one Jaguar XJ13 and any others can only ever be replicas, facsimilies, tributes, recreations, toolroom copies or similar.