S.S.90 and SS Jaguar 100

SS90In 1935 came the S.S.90 – Lyons’ first true sports car – so named to imply its anticipated top speed. The model’s chassis was essentially that of the revised S.S.1 with an underslung rear and 15 inches extracted from its central section. The engine, the 2.6-litre unit with a bore and stroke of 73 mm x 106 mm, had been mildly modified and now developed around 75 bhp. The side-valve cylinder head had been retained although the camshaft was peculiar to the model, and the aluminium cylinder head was an S.S. fitting.

The really significant aspect of the 90 was the bodywork. It was extremely low with wide sylish wings and a very exposed cockpit. Only the prototype had a well finished, rounded tail with the spare wheel concealing the petrol tank which was contained within the bodywork. All production S.S.90s featured an exposed tank and wheel, the original design probably being dispensed with on the grounds of cost.

The 90 sold for a competitive £395, considerably cheaper than the Frazer Nash and Aston Martin models. Sales were, however, disappointing, no doubt due to the limitations of its side-valve power. Even the cheapest sports cars of the day, namely the Singer Le Mans and MG Midgets, featured overhead camshafts.

Lyons was accutely aware of the limitations of the Standard engine and, even though the 90’s top speed was nearly 90mph, he was determined to improve the performance. One of the ideas he contemplated was the use of an American engine. Henly’s, who had obtained the British concession for the Studebaker Corporation, sent a Commander model to the S.S. works for evaluation. Another option was the addition of a Zoller supercharger, and at least one engine was accordingly modified.

It was, however, thanks to Lyons’ association with the Coventry Motor Cylinder Company, who made the firm’s aluminium cylinder heads, that he met the freelance gas-flow expert and engine specialist Harry Weslake. Weslake immediately suggested the use of overhead rather than side valves to improve performance.

When, in May 1935, an experimental version of the 2.6-litre engine utilising Weslake’s new cylinder head design was run, it produced 103.3 bhp at 4400 rpm - far in excess of Lyons’ requirement of 95 bhp.

Shortly after the introduction of the S.S.90, Lyons appointed William Munger Heynes, a gifted young engineer from Humber, as S.S.’s chief engineer. One of Heynes’ first tasks was a formidable: with the assistance of only one draughtsman he had to revise the by now complex S.S. range, designing a new chassis, suspension and steering for the new generation cars to be revealed in only six months time at the Motor Show. This included a new saloon range powered by the Weslake modified 2.5-litre engine, which was also to be used in the S.S. sports car.

At this time the SS name was altered, losing its full stops and being joined by Jaguar. It was Bill Rankin who was to come up with a list of animal and fish names, and Lyons “… immediately pounced on Jaguar because it had an exciting sound”. It was also Rankin who, as a keen amateur sculptor, was to design the famous leaping Jaguar mascot for the car’s radiator. An unimpressed Lyons said that it looked “like a cat shot off a fence”.

Jaguar SS100

SS100It was also 1935 that saw the new Weslake converted engine fitted under the bonnet of the memorable SS100. Although the new SS100’s body and chassis looked virtually identical to the 90, the suspension, brakes, and steering were shared with the new saloon range. The rear ends of the front leaf springs ran in sliding trunnions rather than being shackled and the Girling rod brakes were a great improvement on the previous Bendix cables. A Burman Douglas steering box replaced the earlier Marles Weller box.

The principal difference between the SS100 and the 90 was the 2663cc Weslake modified Standard engine. Twin SU carburettors replaced the RAG units and helped the engine achieve 104 bhp at 4600rpm. Car and driver together totalled 2800 lb and the SS100 was able to accelerate to 50mph in 8.8 seconds, and to 60 mph in 12 seconds, covering the standing quarter mile in just 18.6 seconds.

The SS100 remained in production in substantially unchanged form until late 1937 when further changes were made to the SS saloons which also benefited the sports cars. There was a new box-section chassis which was much stiffer than its predecessor, and the bodywork was now entirely made from steel, which obviated the need for the labout intensive wooden frame. There was also a larger engine, still of Standard ancestory, a 3845cc unit with 82mm x 110mm bore and stroke. The arrival of this engine completed the SS jaguar model line-up, with the 2.5-litre unit remaining in production as well as the small 1.5-litre overhead valve option.

All the SS100s were open two-seaters with the exception of the SS jaguar 100 Fixed Head Coupe. Reminiscent of the Bugatti Atlantique of the period, it was unveiled at the 1938 Motor Show. At £595 it was the most expensive of Jaguar’s pre-war cars and only one was manufactured before the outbreak of World War Two decreed an end to car production.