The Heritage Register

Until recently the JDCA had two Registers covering the classic saloons and sports cars of this period. These were the SS and Pushrods Register and the Large Classic Saloons Register. Whilst the time period covered is long, the number of these vehicles in the Club is relatively small, and it was decided to combine these Registers into a single Register under one Register Secretary.

Sir William Lyons had already established a successful business that began by building stylish and aerodynamic 'Swallow' sidecars for the motor-cycle craze which had grown in England after World War One. In 1928 he then expanded his operation to building bodies and interiors for Austin, Swift, Wolseley and Fiat automobile chassis.  

In 1932 the company, now re-named Swallow Coachbuilding offered the rakish S.S. 1 Coupe. Already Lyons' eye for beautiful design was evident.

The original S.S. name has always eluded those searching for meaning, 'Standard Swallow' and 'Swallow Special' are two conjectures. A drophead coupe and the smaller S.S. 2 soon joined the original model which by 1934 had shed it's cycle type guards for running boards and gained rear side windows for a less claustrophobic interior. This year also saw the introduction of a new body design, the 'Airline', which Sir William disliked but produced because it was fashionable at the time.

The first car called a 'Jaguar' was released in 1935. This S.S. Jaguar was a 2.5 ltr 4 door saloon and remained the basis of production until 1949. A redesigned OHV 'pushrod' 6 cylinder Standard motor from engineer Harry Weslake propelled the new saloon to 90 miles per hour!  It also set the mark for all future saloons carrying the Jaguar name to combine elegance and comfort with performance. Soon an open tourer version was added to the model range.

Another exciting development from 1935 was the appearance of the S.S. 90 sports car. This was soon superseded by the fabulous S.S. 100. Sir William knew the value of rally and racing victories which would boost prestige and publicity for his company. Before the war the 3.5 ltr engined S.S. 100 and also the saloons would be very active in British and international sporting events.

The onset of World War Two saw the S.S. marque change it's production line for the war effort and automobiles were not made. However the fertile mind of Sir William looked ahead to the future and envisaged an independent business that did not rely on outside manufacturers for engine production. He directed engineers like Bill Heynes and Wally Hassan to design a new engine that had to be powerful but also beautiful to look at. 

The apocryphal 'fire-watch' meetings which supposedly took place during the years of air-raids and bombardment by V1 and V2 rockets would result in the famous DOHC XK engine.

With the war Sir William realised that 'S.S.' had negative connotations due to the Nazi organisation of the same name and the company would now be called 'Jaguar'. After the war Sir William also realised that even though Jaguar was in the process of mating the new XK engine to a new saloon design (the Mk VII) it would take some years before this could be done. It was vital for the company to regain it's momentum and much needed export sales.

The solution was the production of what would later be known as the 'Mk IV' saloons. These cars were slightly modified versions of the immediate pre-war saloons and were offered in 1.75, 2.5 and 3.5 ltr versions. A drophead coupe was also available. However it looked a little out of date by the late '40s and a newer style of saloon was needed to maintain sales, especially for the all important U.S. market.

The resulting 1948 Mk V still looked fairly traditional but was sleaker and more streamlined. Mechanically it was certainly more modern with a new rigid chassis, independent front suspension, softer rear springs and hydraulic brakes. The car was only offered in 2.5 and 3.5 ltr versions and could be had in drophead coupe form. The last Mk V came off the production line in 1951. The Mk V Jaguar is still a very useable classic car today! 

The Mk VII was finally launched to world acclaim in 1950. The saloons cemented William Lyons sales slogan of “Grace Pace and Space” and went on to become the genesis for all Jaguar saloons from then on, with quality build, luxury, high performance, and good value for the money. 

October 1954 saw the release of the Mk VIIM, it was an upgraded Mk VII but with changes such as head lamps single piece glass with a “J” logo in the center slightly larger red lens tail lights same as XK 140. There was the addition of flashing turn indicators, separate round amber at front, and utilizing the stop lamp at rear. round horn grills replaced the driving lamps which were moved from the below the headlamps to the valance panel directly behind and looking over the front bumper bar

Ronnie Adams had a number of successes in the big Mark VII including victory in the 1956 Monte Carlo Rally. Thus, Jaguar became the first manufacturer ever to win both Le Mans and the Monte Carlo Rally in the same year

Next came the Mk IX in October 1958 On the outside it was indistinguishable from the previous Mk VIII except for a rear boot badge. Early Mk IXs had the same tail lamps carried over from Mk VIII, however later models had larger tail lights incorporating an amber turn lens on top of the red stop and tail mounted on a chrome plinth similar to the compact Mk II saloon and late XK 150 and engine capacity increased to 3.8 litre and disc brakes were introduced

In October 1961 the new Mark X a replacement for the Mark IX however this was no evolutionary update but a completely new concept. While the Mark V II to IX had a separate chassis, the Mark X was of full monocoque construction. 

It employed a widened version of the new independent rear suspension as fitted to the E-type and was fitted with the same engine. The car was very large by European standards, but was designed with the US market in mind. It seated five people and capable of transporting four or five people quickly and in great comfort. In 1964 Mk X was fitted with 43.2 litre engine

October 1966 saw the Mark 10 rebadged as the 420G.  The body shape was unchanged from the Mark X. There was chrome trim on the sides with integrated small blinker signals, the radiator grille divided with strong middle bar, the dashboard topped with upholstery and a central clock Ttwo-tone colour on demand.

Ultimately these cars were replaced by the new XJ saloons

The Daimler DS420 was based on the Jaguar Mk X and produced by Jaguar, it was introduced by British Leyland to provide a replacement limousine after the demise of the Daimler Majestic Major DR450 and Austin Princess. Of the 4981 cars produced, 835 were body less, for custom coach building. As most were bespoke, performance figures are meaningless. It is assumed they were similar but slightly worse than the Mk X Jaguar at their introduction, and development of these cars paralleled approximately those of the Jaguar XJ6 saloons in engines, drivelines and other technical improvements right up to their end in the early 1990s.

For more detailed descriptions on the various models we recommend Nigel Thorley’s book “Jaguar Mark VII to 420G, The Complete Companion.” Still available (usually 2nd hand) through some specialist bookstores or it can be borrowed by Club Members from the JDCA library.