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.”


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:

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


Transform your Classic Jaguar.


“to the power of 12”

from the Greek – “teras” = monster.

Contact us for details

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 …


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?


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.

Today in the Workshop …..

Today in the workshop …

Original 1966 Jaguar V12 Prototype Quad-Cam Engine …. Street-Legal re-created XJ13 …. polished XJ13 in progress … “Building The Legend” Quad-Cam 7.7-litre V12 …. Lightweight E-Type front suspension ….

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.


Jaguar XJ13, Building The Legend, Street-Legal, XJ13, Jaguar

A valuable piece of paper!

A fully road-legal, IVA-tested, 2019-plate car that be driven on the road in the UK (can be registered in other EC and International countries subject to minor formalities).

Imagine it …. a quad-cam V12-powered car that could have squared up to cars on the 1966 Le Mans grid …. and one that can be driven on the road …..

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.

Doodling ….

….what might a privateer Jaguar XJ13 have looked like in ’67? …… 1967 Le Mans – the “sweet spot” for some of the most beautiful race-cars in history – the mighty Ford GT40, the sublime Ferrari 330 P4, the gorgeous Porsche 906 – varied entries from marques such as Marcos, Alpine, Abarth, Matra. Truly a special “moment in time” …. Any thoughts?

Jaguar, XJ13, Le Mans, 1967, Ferrari, GT40, P4, 330, Lola, T70, Porsche 906, Building The Legend

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.

A bit of cam-timing …

Building The Legend, Quad-Cam, tera-, V12

A bit of cam-timing on our own full-race, quad-cam V12 ……

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
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.

Ecurie Cars Logo.png

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.

How many quad-cam V12s were built and where are they now?

XJ13 Original Quad-Cam V12

A question often asked of me is,

“How many prototype V12 quad-cam engines were built by Jaguar and where are they now?”

As I reported on this blog back in May 2010, the answer is SIX. Of this six, only three progressed beyond test-bed stage and were installed in cars. A seventh engine was assembled as a 60° V8 and run on Jaguar’s test bed. The V12 block for this engine was converted into a V8 using a special crankshaft with throws for only eight of the twelve cylinders. There were plans to assemble an eighth engine but it never reached the test bed stage.

The above has now been confirmed by XJ13-expert Peter Wilson in an excerpt from his forthcoming book which appears in the November 2011 issue of “Jaguar World”. I can now add further confirmation of these facts from a collection of previously unknown and unpublished original documentation. These documents were in the personal collection of the late Claude Baily – the architect of Jaguar’s quad-cam V12, their legendary XK engine and quad-cam 90° 8 litre V8 amongst others.

XJ13 - Building the Legend
Claude Baily

Claude Baily joined the SS Jaguar drawing office during the second World War and his engineering talents were soon exploited by Jaguar. Baily became intimately involved in Jaguar’s plans to replace their pre-war engine designs with a new generation of engines designed to power their latest saloons. He is perhaps best known for his part in the design of the legendary XK twin-cam engine.

XJ13 - Building the Legend
Claud Baily’s appointment letter.
© Copyright Tony Bailey (WPO Communications) – not to be reproduced without permission.

Spending long war-time nights fire-watching in a small office above the assembly tracks in Coventry, in the company of William Lyons, William Heynes and Walter Hassan, the architecture of the world-beating XK engine was laid down. The new engine was required to reliably provide a minimum of 160bhp, have a long service life and be refined in operation. Before the end of the war, a number of experimental single-cylinder and full engines were evaluated. The following original document from 1941 is likely to relate to one such experimental engine. J.A.Prestwich was better known by its initials “J.A.P.” whose engines were used in many famous motorcycle marques and early aeroplanes. Customers included Morgan, Triumph, Brough Superior, AJS and HRD.

XJ13 - Building the Legend
12th December 1941 – letter to SS Cars referring to experimental engine.
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4, 6, 8 and 12 cylinder configurations were all considered at this very early stage but it was the 4 and 6 cylinder versions that were finally adopted. It has to be said that the BMW 328 engine played an important part in formulating the architecture of these engines. Indeed, Heynes was great friends with an owner of a 328, Leslie Johnson, who loaned his 328 to SS Cars for evaluation.  Johnson was a British racing driver who competed in rallies, hill climbs, sports car races and Grand Prix races. Johnson’s car was highly developed and had raced pre-war. In my opinion, the styling of the XK120 owes much to the BMW. A BMW saloon was also acquired by SS during the war and was fitted with one of the early experimental engines (the “XG”). Walter Hassan used this car as his own personal transport for an extended period for evaluation. One of Jaguar’s own 2.5 litre SS Saloons was also used for testing the prototype engines although most of the development work was carried out on the test bed.

XJ13 - Building the Legend
3.5 litre experimental XK engine – drawing produced to calculate compression ration.
© Copyright image – not to be reproduced without permission.
XJ13 - Building the Legend

Left to right – Walter Hassan, William Heynes, Claude Baily.
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Heynes and Baily applied all their thoughts on engine design to the XK engine although they later commissioned Henry “Harry” Weslake to help optimise their design. Jaguar already had a long association with Weslake, a cylinder head specialist who had been instrumental in modifying the side valve standard engine used in the first SS sports car. He also worked on the larger SS engine. It is believed he was involved in the design of every Jaguar engine up to and including the V12 of the early 1970s.

XJ13 - Building the Legend
Harry Weslake – © Copyright image – not to be reproduced without permission.

The following Weslake report gives a fascinating insight into his evaluation methods and his closing summary bears testament to the soundness of the XK basic design. Weslake concludes:

“…. The engine has stood up remarkably well through these series of tests. The valve gear has remained quiet throughout, there has been no sign of variation in oil pressure and the engine improves in power out-put the longer it runs. The tests have been very severe, particularly the distribution ones, but never once was any mechanical trouble experienced. It is suggested that some breather attachment should be developed in order to keep a small depression in the crankcase so that oil corrosion can be minimised and this would also help to stop oil leaks, particularly in the valve chest covers …”

XJ13 - Building the Legend

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XJ13 - Building the Legend
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XJ13 - Building the Legend
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XJ13 - Building the Legend

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XJ13 - Building the Legend
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XJ13 - Building the Legend
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XJ13 - Building the Legend
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The camshaft drive was by duplex roller chain – an arrangement that was carried forward to the quad-cam V12 prototype engines. This arrangement was used in the first engine installed in the XJ13 as well as the second engine built and tested in a Mk.10 Jaguar. The “genetics” of the XK engine could clearly be seen in the later quad-cam V12. The following page of sketches (made by Claude Baily around 1949/50) clearly show how he was formulating a suitable cam drive for a quad-cam engine. It is believed the sketches were produced as a precursor to designing and building a quad-cam 8-litre 90° V8 engine for a post-war military application. A similar architecture found its way into Baily’s quad-cam V12.

XJ13 - Building the Legend
Baily’s drawings showing his ideas for a quad-cam duplex chain drive
© Copyright image – not to be reproduced without permission.

Claude Baily had been working on a quad-cam 60° since 1949/50 – perhaps earlier. By the February of 1951 a fully-working engine may have been running on the test bed. This 12-cylinder engine was later developed as an 8-cylinder variant for military use. The following quad-cam V12 performance data was recorded on the 19th February 1951.

XJ13 - Building the Legend
Claud Baily’s 1950/51 60° quad-cam 8-litre V12 engine performance data.
© Copyright image – not to be reproduced without permission.

The following picture shows Baily’s data in his own hand. Was this an estimate/conjecture or are they figures actually recorded on the test bed?

XJ13 - Building the Legend
Claud Baily’s 1950/51 notes.
© Copyright image – not to be reproduced without permission.

In 1962, Baily was given the go-ahead to develop his design as a 5 litre V12 to challenge at Le Mans. Although primarily designed for racing, consideration was also given to using the engine in production cars. At least two years before the go-ahead, Baily’s 60° V12 engine was being proposed as a future Jaguar engine with a range of possible capacities as the following memo from Claude Baily to William Heynes demonstrates:

XJ13 - Building the Legend
5th December 1960 memo – “POSSIBLE FUTURE RANGE”.
© Copyright image – not to be reproduced without permission.

The quad-cam V12 engine project was given the code “XJ6” – not to be confused with the saloon of the same name. “XJ6” followed on from “XJ5” which was the code name given to the Mk10 replacement (eventually to become the 420G). Two Mk.10 cars (XJ5/4 and XJ5/5) were to become mules for the production variant of the “XJ6” racing engine. The following memo confirms that six prototype engines were being developed.

XJ13 - Building the Legend

25th November 1964 memo – “12 CYLINDER ENGINES”.
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The first two engines (XJ6/1 & XJ6/2) were first assembled to almost identical specifications which included dry-sump lubrication and Lucas mechanical fuel injection. In April 1966 XJ6/1 was installed in the XJ13. The second engine, XJ6/2, was installed in a Mk10 Jaguar (XJ5/5 – manual gearbox) on 14th April 1965. It was converted to wet-sump lubrication although its Lucas fuel injection system remained. After six months of testing in the Mk.10, XJ6/2 was removed from the car and reunited with a dry sump for further test bed development. In March 1966 it’s dry sump was again converted to enable fitment in a second Mk.10 (XJ5/4 – automatic gearbox). By this time it had acquired a sextet of SU carburettors. It ran for almost 35,000 miles in this car before it was removed and replaced in XJ5/5. It was finally removed from the latter car and placed on the test bed for further development/testing until it was put into store in March of 1969. It remained as a complete engine until I acquired it in 2010. It is now being rebuilt to its original specification and will be placed in my replica of the 1966 XJ13.

So, to answer the question “How many quad-cam V12s were built and where are they now?” SIX quad-cam V12 engines were built.

  • XJ6/1 The first quad-cam V12 built but only the second to leave the test-bed and be installed in a car (XJ4/1).  Damaged in 1967 and retained as a spare by Jaguar. 
  • XJ6/2 The second quad-cam V12 built and the first to be installed in a car (XJ5/5) Survived as a complete engine and sold by Jaguar in the mid 1970s. Currently under restoration to original specification (same build spec as XJ6/1).
  • XJ6/3 Only ever ran on the test bed in a variety of configurations. Has not survived.
  • XJ6/4 Built using cast iron block and ran on test bed. Has not survived.
  • XJ6/5 Internally modified to run as a V8. Ran on test bed for a short while in 1965. Surviving components are with a collector in the US.
  • XJ6/6 No records exist. It is believed this engine was never actually assembled.
  • XJ6/7 Built to trial a die-cast “open-deck” engine block.  Installed in XJ4/1 (XJ13) to replace its original engine when damaged in 1967. Remains in the car to this day.
  • XJ6/8 Built to competition spec with ultimate development of cylinder heads but never left the test bed. Cannibalised whilst in storage in 1969. Cylinder heads placed on XJ6/2 which remain with it until today. The engine block found its way into an XJ13 replica built by Bryam Wingfield for the collector Walter Hill. 

It is interesting to note that Jaguar’s XJ13 currently has a die-cast block that differs from its original XJ6/1. This die-casting process is used to reduce costs and will have been more relevant for a production as opposed to competition engine. The following letter indicates the target casting weight of a V12 block (OXW 5620 is an experimental part number current at the time of quad-cam testing)

XJ13 - Building the Legend
XJ13 - Building the Legend
Die Casting Quote.
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The XJ13’s rather poor power to weight ratio when compared with its likely Le Mans competitors may have contributed to this attempt to lighten its weight?

As Mike Kimberley recorded after a test of the XJ13 at Silverstone in 1967:

BHP per lb weight

  • Ferrari P4/ .210
  • Lola Chev/ .207
  • Ford Mk4/ .206
  • XJ13/ .177

It is also interesting to note that the engine currently installed in the XJ13 has a single OPUS 12 cylinder distributor. Its original engine, XJ6/1, as well as XJ6/2 were fitted with twin 6-cylinder distributors.

XJ13 - Building the Legend

XJ6/2 Original twin distributors as originally fitted to XJ6/1.
© Neville Swales.
XJ13 - Building the Legend
XJ13 single 12-cylinder distributor on XJ6/7 engine.
© Neville Swales.

The rebuilt XJ6/2 will, of course, be built using its original twin distributors. In 1966 Claude Baily was charged with pricing the OPUS system. The following letters give an interesting insight – comparing the various options under consideration.

XJ13 - Building the Legend
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XJ13 - Building the Legend
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XJ13 - Building the Legend
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There are other differences between the XJ13’s original engine (XJ6/1) and the one currently installed in the car (XJ6/7). One is the inlet manifold throttle bodies. The first photo shows the original (1967) arrangement with dual throttle bodies (and separate mounting plates – coloured yellow) and the second shows the current arrangement (photo taken 1973) with individual throttle bodies and a single mounting plate on each head. Note also the different cam cover treatment – the earlier engine has the “trademark” polished cam covers wheras the currently-installed engine has a crackle-black finish.

XJ13 - Building the Legend

1967 (original car)
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XJ13 - Building the Legend
1973 (rebuilt car)
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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.