Jaguar Mark 1’ 2.4 litre, a classic saloon

To many today, the Jaguar 2.4 seems merely a somewhat dull and rarely- seen model from the company's distant past. After all, wasn't the 2.4 one of the smallest-engined and slowest Jaguar ever made, and didn't nearly all of them rust away - probably deservedly?  The truth is that in the 2.4-litre of 1955 lies the genesis of the ultra refined jaguars of today, and for this reason alone it's one of the most significant saloons in the company's history. New, it was amongst the quietest and best riding cars in existence - at any price and was not the slouch its specification might suggest. Nor in Jaguar terms was its engine inappropriately’ small: a fact often overlooked is that, up to 1949, Jaguar’s most popular models were only 1.7 litres.

During the war years William Lyons felt that even this capacity might be too big for post war condition, and seriously contemplated a really tiny Jaguar of about 12,00cc. But when the new XK-engined  XK-120 and MK VII models arrived in 1949/50, demand from the US was massively greater than anticipated, banishing all thoughts of small- engined Jaguars for the UK and Europe. Almost all thoughts. Lyons still hankered after a slice of what had been the relatively high volume 1.5 litre saloon market that Jaguar had left when the Mk V 2.5/3.5 replaced the old range in 1949. So, in 1952 - safely ensconced is the new browns lane plant - Lyons started with a clean sheet of paper for his 'small Jaguar' design, for which the only carry over parts would be a variant of the XK engine and existing transmission. The XK family of engines included the 3.4 six- cylinder used for the XK 120 and Mk VII, plus a 2.0 litre four cylinders developed but kept under wraps. However, the ‘four-pot’ lacked smoothness so the 3.4 six cylinder’s stroke was reduced from 106 to 76.5 mm (and its block height by almost three inches) to produce a smooth and free running 2,483cc engine which could use the existing cylinder head and retain a beefy seven bearing crankshaft.

The bodyshell was a more onerous proposition; by the early 1950s the separate chassis frame was fast being replaced by unitary construction, which combined bodyshell and frame in one unit – reduced weight and potentially greater torsional rigidity being the twin goals. Design was more difficult and tooling cost was greater, however, so adopting a unitary body amounted to a massive commitment by Jaguar. Few if any other specialist car companies producing less than 9,000 cars a year would have risked the investment, but Lyons followed the advice of his chief engineer William Heynes and went for it. 

Heynes laid out the car’s basic parameters while Lyons evolved the shape. It was then up to design draughtsman Tom Jones “to engineer in between” as he puts it, establishing the basic architecture. The design then went to Jaguar’s body man Cyril Crouch, who spent hundreds of hours devising the body tooling which pressed steel at Cowley.

The first prototype, completed at the end of 1954 and finally Jaguar launched the 2.4 Mark 1 to the dealers at a big convention held under canvas at browns lane. The dealers were happy to see a right car at the right time and with the right price.  Publicly, there was a televised introduction to the Jaguar Mark1 2.4 litre, at the RAC’s country club, hosted by Raymond Baxter and involving Lofty England, Mike Hawthorn and other Jaguar’s successful race team.