By the middle of 1936, with the new ‘Speed Model’ working quite well and with most of the old 1½ litre cars now sold by the various dealers, attention was turned towards making a production car on the new chassis, a idea which had in fact always been planned for.
Sutherland was acutely aware that the market for out and out sports cars was a limited one and this was emphasized by the tailing off of sales of the ‘Mark II’. Initially, many of the orders for the ‘Speed Model’ had been to customers who had taken them out on the track almost immediately. Two such cars were built by the competition department, one for Dick Seaman to drive in the Ards TT race and one for Allan Phipps, a wealthy American amateur who had owned an ‘Ulster’. These had been very successful, if not completely reliable, so it seemed reasonable to seriously consider making a new car based on the Speed Model chassis with a de-tuned version of the new engine. This was called simply the ‘2 litre’, and later the ‘15/98’.
At least five chassis, the first being a short chassis and the remainders long chassis, were laid down while the Speed Models were being built, obviously with full scale production in mind. Very late in the day two of these cars, a four seater tourer and a saloon were assembled for the Motor Show in October of 1936, to accompany the E. Bertelli Ltd. 2/4 seater bodied ’Speed Model’. These were in fact towed to the show, because there simply was not time to test them sufficiently to be confident about getting them there under their own power. They were reasonably well received and almost thirty orders were taken at the show which was very encouraging.
As a result of these orders a production schedule was set for one hundred and fifty cars. A contract was made with E. Bertelli Ltd. to build one-hundred saloons and twenty-five tourers and production got underway. However when the first saloon was tested it was found to be truly awful, with terrible handling, very noisy and with a bad vibration period caused by the ‘out of balance’ characteristic vibration of the four cylinder engine resonating with the relatively long chassis. These problems were so bad and so difficult to rectify that the production strategy had to be completely re-thought. An interim solution, directed towards the symptoms rather than the cause, was to fit heavier sound proofing and Wilmott Breedon ‘Stabilising Bumpers’, which could be ‘tuned’ to the offending vibration period by adding or removing lead washers from the containers at each end of the spring steel bumper blade. As a result of these, as yet unresolved difficulties, orders for the saloons and four seater tourers with E. Bertelli Ltd. was severely reduced. It was clear that to enable the factory to produce a car that could be sold they had to revert back to selling 2/4 seaters on the shorter chassis. This sudden change in policy and the impact it had on Harry Bertelli’s business was the main reason that Bert Bertelli resigned from the company. E. Bertelli Ltd. were quietly compensated for the loss of work, since the unfortunate backing out of the contract was bad enough, but the adverse publicity of why Aston Martin had to take the action they did, would have been far worse.
So, after a much shortened run of saloons and tourers, a batch of short chassis cars were produced. Most were with built with the open 2/4 seat tourer coachwork, with the remainder being built as rather elegant drop head coupes. The ‘Speed Model’ had been a specialized sports car and expensive to develop and build, so it was clear to Sutherland that for the ‘15/98’ to be financially successful, it would need to be built with costs very much reduced. One of the means by which this was achieved was to subcontract the 2/4 seater bodies to Abbey Coachworks and the Drop Head Coupe to Abbots of Farnham. Furthermore, the complete Girling rod brake system was bought in, as was the front axle (by Alford and Alder), and the gearbox, (a Moss box) with double helical gears and synchromesh on 2nd, 3rd and 4th speeds.
The ‘15/98’ had a de-tuned version of the ‘Speed Model’ engine, with wet sump, 1 ¼" carburettors and a different and lower lift camshaft, but which gave good mid range torque. The car was very little quicker than the lighter 1½ litre cars, but the extra power and torque made for a very comfortable touring car. Where the 1½ litre cars had been ‘screamers’ which needed fairly frequent gear changes to keep the engine within a reasonable power range, the ‘15/98’ was a much more relaxed affair, the new engine being quite capable of dragging the heavier car along even up relatively steep gradients without resorting to use of the gearbox nearly so much.
The short chassis was virtually identical to that of the ‘Speed Model’, the only difference being the rear most channel cross member which was now slightly smaller and in a lighter gauge, pressed rather than of welded and fabricated construction. Whereas the ‘Speed Model’ had its Hartford friction dampers attached to this cross member (behind the rear axle), the ‘15/98’ now had Luvax hydraulic shock absorbers mounted directly onto the chassis side member just ahead of the axle and linked onto the rear axle tube via a short rubber bushed rod. The fronts however were still friction dampers exactly as per the ‘Speed Model’.
Up to and including the ‘Speed Model’, all Aston Martins had relatively short and stiff springs, which had much to do with the very good handling of these cars. However, for the ‘15/98’, it was recognized that as a touring car comfort would be paramount, so the rear springs were both lighter and longer. This was achieved by moving the spring mounting pin forward and it also had the effect of shortening the wheelbase to eight foot three inches. The front springs were the same length but had a lighter rating. The result was a very comfortable ride, but the precise and predictable handling, so characteristic of the earlier cars, was somewhat sacrificed. However, the new short chassis ‘15/98’ was comfortable, roomy and easy to drive, and it had as much performance as was needed for a touring car.
The coachwork was effectively the E. Bertelli Ltd. design that had been used on the Type ‘A’ ‘Speed Model’, slightly lengthened at the rear with a shallower slope, with the spare bolted onto the rear of the body. It had slightly more flowing wings which did not have the coachbuilt detailing that was typical of Harry Bertelli’s work (and expensive to make). It was nevertheless attractive and reasonably well appointed. One styling feature which did carry over from the 1½ litre cars was the exhaust system, the two downpipes exiting a pair of heavily finned manifolds out of the bonnet and through the right hand wing, being clad in the familiar chromed copper outers that had been such an iconic feature of the earlier cars. The louvred (now fixed) radiator sloped back much more than the earlier cars, but the fold flat windscreen with wind deflectors which doubled as aero screens was retained, albeit now a slightly cheaper design.
The long chassis cars necessarily had a slightly different chassis due to its extra length and the need for greater rigidity. This was achieved by a much heavier and wider central cross member with longer bracing flanges which required a different method of mounting the rear of the gearbox, and an altered arrangement for the handbrake. Heavier springs were fitted to cope with the extra weight. Slightly higher gear ratios were used in the rear axle but engine specification was identical for both long and short chassis cars. The two door four seat tourer, with coachwork by E. Bertelli Ltd., was essentially a longer version of the 2/4 seater but with slightly shorter and more humped front wings leading into much longer running boards. It also had a simplified windscreen which folded flat but did not have wind deflectors. This may well have been a cost saving exercise. If it was, the savings were directed towards an onboard jacking system by Luvax, the four individual hydraulic jacks being actuated by a hand operated pump located just in front of the passenger seat underneath the floorboards. This Luvax Jackall system was also used on the Saloon and the Drop Head Coupe. The tourer had an opening boot with an integral parcel shelf and storage for the side screens, very much like the long chassis ‘Le Mans’ and ‘Mark II’, and like them the spare wheel was mounted on the boot and countersunk into the boot panel itself. When mounted the spare wheel was slightly greater in diameter than the depth of the panel and this was dealt with by simply not continuing the line of the bottom of the boot from one side to the other. This looked odd and unfinished without the spare mounted but did not detract from the lines of the car and was almost invisible when the spare was attached.
The Saloon body, (also built at Feltham by E. Bertelli Ltd.), was in effect, not much more than a roofed version of the tourer, with four doors. Most saloons had a sliding panel in the roof and all were very well finished inside with polished mahogany cappings to the dash and doors and attractive art deco handles and fittings. Beautifully coachbuilt by Harry Bertelli, they were very high quality cars, if anything the coachwork being better than the chassis and engine. Had it been silent and without the vibration problems, and perhaps with a little more power, it would have been a very nice car indeed.