Sunbeam Alpine Sports Roadster is named after the tough international rally in which the Sunbeam-Talbot 90 had been so successful. Introduced in March 1953, the Alpine was initially available only for export, most of them going to America. It become availabe for the home market in the autumn. It is based on the 90 mechanically but with differences such as a tuned version of the 2267-cc engine, strengthened chassis and suspension, modified gearbox ratios and a straight-through silencer. The entirely new two-seater body is similar in general outline to the 90 Convertible but is immediately distinguishable by its louvred bonnet top and long rear decking. Either a single-pane windscreen plus side panels, or a curved transparent-plastic racing screen could be fitted. The bodies are finished and trimmed by Mulliners of Birmingham.
Modifications introduced on the Sunbeam-Talbot 90 Mark IIA announced in September 1952 include perforated disc wheels with new chrome hub caps and rim embellishers, the deletion of the rear-wheel spats and the fitting of larger brakes. The Convertible version is similarly modified.
SUCCESSFUL COMPETITOR: Introduced in the early part of 1953 the new Sunbeam Alpine has won a striking series of rally successes during the past year and has demonstrated that when fitted with certain optional extra equipment it will exceed 120 m.p.h. A particularly practical feature of this high performance car is the comfortable seating and the exceedingly large enclosed luggage space.
The Motor YEAR BOOK, 1954 BRITISH CARS OF 1953 SUNBEAM ALPINE
The Sunbeam Alpine engine differs from the "90" (which is used as a basis, both in the interests of economical production and because of its well-proved qualities) in having a special head giving a compression ratio of 7.42 : 1, as opposed to 6.45 : 1. The combustion chambers follow the same form, but the ports have been modified to give a better gas flow by shortening the valve guides and cutting away the surrounding metal where they protrude into the ports, whilst the machining of the ports themselves is more extensive.
A straight-through Burgers silencer is used and is located outside the chassis-frame members in an unobstructed air stream. The carburettor is a type DAA 36 downdraught Stromberg, with a hand-operated choke, and the manifold hotspot has been modified to reduce the degree of heat transference, this being done by partially insulating the metal plate which conducts heat from the exhaust to the inlet.
An over-riding manual control is provided for the ignition, enabling the total range of advance and retard provided by the automatic centrifugal and vacuum devices to be vafied over a range of 14 deg. (on the flywheel). The control takes the form of a knob which is pulled out for advance.
Other points of difference compared with the "90" engine are the incorporation of a detachable white-metal bearing at the rear end of the camshaft (instead of the latter running direct in the block), the use of a Lucas high-voltage sports coil, the fitting of an oil-bath air cleaner and the use of a four-row radiator block which increases the cooling capacity. The top of the bonnet is louvered to reduce under-bonnet temperatures, but detachable blanking plates are provided to enable the apertures to be closed when not required. The net result of these engine changes is to increase the maximum output from 70 b.h.p. at 4,000 r.p.m. to 80 b.h.p. at 4,200 r.p.m.
In the transmission, the only mechanical change is a variation in the constant-mesh pinions, from a pair with 21 and 29 teeth respectively, to a pair with 22 and 27 teeth, so as to provide higher and closer overall ratios. The oil capacity of the gearbox has also been increased (by half pint) to prevent surge from causing temporary bearing starvation. To avoid leakage with the higher level, the separate breather has been eliminated and a new breather incorporated with the dipstick.
A notable alteration to the "90" chassis frame is the addition of a pair of side plates welded to each side member at the point where it is upswept at the front, these acting as stiffening webs for the underside angle of the upsweep and also serving to provide a mounting for a 2-in. diameter tubular cross-member which passes below the engine. The lower extremities of the plates are boxed and the cross-member has a flanged mounting which enables it to be detached for sump removal. By this means the depth of the frame at this important point is increased from 10 in. to 14 in. (the remainder of the side members being 6-in. deep as before) and this, in conjunction with the crossmember, has served to stiffen up the already sturdy frame to a very marked degree.
The front coil springs have been stiffened, the rate on this model being 104 lb./in. instead of the normal 68 lb., and roll resistance has been augmented by an increase in the diameter of the anti-roll bar from 9/16 in. to 5/8 in. A further point is the adoption of harder settings for the R-type Armstrong shock absorbers.
With competition usage in view, a higher steering ratio (17.5 : 1) is used, this having the effect of reducing the number of turns of the steering wheel from lock to lock from 3.6 to 2.6.
The entirely new body is a two-seater pure and simple, with separate seats shaped to give good individual support. In addition, there is a fixed centre arm rest, with further arm rests (shaped to act as door pulls) on the doors, thus giving particularly good allround support. Each seat is adjustable for reach and, in addition, the height and rake of the driver's seat can be adjusted as well. The seats tip up bodily to provide access to a large recess which houses the hood and side screens, and a good point is that stays are provided to hold the seats in the tilted position.
There is provision for a radio panel, heater installation and a rev. counter (centrally fitted below the facia), all like white-walled tyres and a cockpit cover, available as factory-fitted extras. An optional item is an alternative axle ratio (4.22 : 1).
The curved single-pane screen with side extensions is readily detachable and a racing screen of curved transparent plastic can be substituted. The hood disappears completely behind the seat and its hood irons are cleverly arranged so that their pivot points run in vertical slides within the body; thus, when the hood fabric (of Egyptian cotton) is detached from the screen and the rear decking, the hood irons can be brought together and slid down bodily into the recess. When erected, the hood extends some 10 in. behind the seats so as to preserve a good sweeping line without curtailing headroom, and its plastic back light can be opened by means of zip fasteners.
The side screens are metal-framed and incorporate horizontally-sliding panels of heavy gauge transparent plastic.
Outstanding for a car of this type is the luggage boot (provided with a key which fits the cubby locker but not the ignition), which measures no less than 49 in. from front to rear, has a minimum width of 39½ - in., will carry a 14 in.-deep suitcase in the forward portion and has a total capacity of approximately 14 cu. ft. The spare wheel has its own compartment below the boot.
The Motor Year Book 1954
Sheila van Damm, Francoise Clarke and Anne Hall crewed this works Mk IIA on the 1953 Monte, but only managed 90th place.
Stirling Moss and John Cutts in a works Alpine on the '53 Alpine Rally. Moss won a Coupé des Alpes and came 14th overall.