The Motor YEAR BOOK, 1954 BRITISH CARS OF 1953 ASTON MARTIN DB2-4
During the course of three years' intensive competition work the power output of the DB II Aston Martin has been raised from the 116 b.h.p., which sufficed to win the 3-litre category at Le Mans in 1950, to 125 b.h.p. Correspondingly, the maximum b.m.e.p. has been increased from 128 lb./sq. in. at 3,000 r.p.m. to 140 lb./sq. in. at 3,500 r.p.m.
As the works team has had a most successful season using the short, light open DB III S model fitted with a 3-litre engine, it was decided to use the increment in power to increase the accommodation on the DB II (and thus to extend its all-round usefulness) rather than as a means of endowing it solely with higher speed or greater acceleration. With this end in view the DB II has been replaced by the DB2-4 which has greatly increased luggage accommodation and two small seats in the tail of the car.
The weight of the car, as disclosed in the data panel, shows that the new body has exacted a weight penalty of some 7 per cent., and it is therefore reassuring to note that the torque of the engine has been increased by 9½ per cent. and that the power per unladen ton has actually gone up from 95 to 119 b.h.p.
The main mechanical features of the engine remain unchanged. That is to say, a very deep iron casting gives 360 degrees support for the four main crankshaft bearings which together with the shaft are inserted endwise into the block. The main casting also divides the outer walls of the water jackets, the cylinder liners being individually inserted and hence readily replaceable when necessary.
The cylinder head carries two valves each 30 degrees from the vertical, the six separate inlet ports lying on the inside of the engine with six exhaust ports on the right-hand side. Two overhead-camshafts are used, driven by a duplex chain from the front of the engine and attacking the valves through the medium of inverted pistons. After initial fitting no further adjustment is needed.
Mixture is fed to the engine by two horizontal S.U. carburettors, each in turn drawing air through separate Vokes-type filters. The power is transmitted through a four-speed David Brown gearbox giving synchromesh on the upper three ratios, and choice of three final back-axle ratios is provided, the alternatives from the 3.73 : 1 used for the purposes of the data panel being 4.1 and 3.5 : 1 respectively.
The front end and centre section of the chassis of the newly introduced DB2-4 are identical with the preceding DB II. That is to say, the frame is a built-up construction of square tubes, and the front wheels are attached by a system of trailing arms in conjunction with vertical coil springs. Similar springs are used at the back of the car, the rear axle being located by single trailing arms and a Panhard rod.
It is behind the location point of the rear springs that the changes distinguishing the new model are to be found. By modifications to the frame and petrol tank design (and by reducing the capacity of the latter from 19 to 17 gallons) it has been possible to provide a clear space above the tank which runs from behind the individually-adjustable front seats to the extreme tail of the car.
The designers have made most ingenious use of the opportunities thus presented. Immediately over the rear axle they have provided two miniature seats which provide ample comfort for two children of preparatory school age, thus making it possible for a man and wife with a young family to use the car for everyday touring. So loaded, considerable luggage space remains behind the occasional seats and remarkably easy access to this space is offered by the design of the tail of the car.
As can be seen from an illustration, the entire rear section of the body can be opened by lifting it around a hinge placed above the top of the greatly-enlarged rear window. Great care has been taken to make this exceptionally large opening dust-proof and water-tight, and in conjunction with this constructional change the top of the roof has been lifted slightly so as to provide greater headroom above the occasional seats. If the latter are not required the luggage accommodation can be more than doubled.
This is effected by folding down the back of the rear seats thus providing a clear platform having a length of 50 in. and a minimum width of 40 in.
This transformation gives the Aston Martin DB2-4 an unrivalled luggage-carrying capacity in a car which should be capable in favourable circumstances of achieving two miles a minute.
The Motor Year Book 1954