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Alvis history                    
Alvis side valve cars
Alvis 12/50 12/60
Alvis 14.75hp & Silver Eagle
Alvis front wheel drive
Alvis Speed Twenty
Alvis Firefly & Firebird 
Alvis Crested Eagle
Alvis Speed 25 & 4.3 litre
Alvis Seventeen & Silver Crest
Alvis TA14 & TB14
Alvis 3 litre
Alvis T21 3 litres
Alvis competition history

Alvis side valve cars 1920 - 1925
our thanks to the Alvis owners club


Alvis' entry into car manufacture came with the 10/30 in 1920. This was a high quality light car with a four-cylinder fixed head monobloc side valve engine of 65 x 110 mm, 1460 cc. A three bearing crankshaft was used, carried in an aluminium crankcase bolted to the cast iron block, with a separate four-speed right hand change gearbox, at a time when these features were unusual in light cars. All of the mechanical parts were of Alvis design and manufacture. Wheelbase was 9'2" and steel artillery wheels were standard. Maximum speed was some 60 mph. In 1921 the range was extended to include the 68 x 110 mm, 1598 cc 11/40, a model more sporting in character offered either on the previous chassis or with a shorter, 9'0" wheelbase, and this was renamed the 12/40 in 1922.

1922 10/30 Cross & Ellis 2 - seater

Next year a 9'4" wheelbase version appeared. The chassis was of conventional design for the period, with half-elliptic springs all round and beam axles, the engine and gearbox being carried in a subframe. Alvis designed brakes operated on the rear wheels only. From the very start, Alvis fitted their own design of cast aluminium rear axle, with fully floating halfshafts. Despite many detail design changes and the use of many different final drive ratios, this axle remained a recognisable feature of most Alvis cars until 1940. A worm and wheel steering box of Alvis' own design and manufacture was employed, giving the customary high gearing of the vintage period. It is believed that upwards of 2,700 side valve Alvises were made but only a handful exist today.

1922 11/40 Cross & Ellis Tourer

They were discontinued in 1925 in favour of the overhead valve 12/50 when the success of the latter demanded all the company's resources. At this time the majority of the cars produced had open coachwork, most of the 10/30s were two seaters, some more sporting than others, but the 11/40 and 12/40 also appeared in four seater tourer and saloon incarnations. The rakish "ducks-back" polished aluminium (usually) sports 2 seater body, so called from the shape of the pointed tail with spare wheel underneath, made its appearance very early on.

1923 12/40 Carbodies saloon

Wheelbase 2794 mm 110 in
Track front 1270 mm 50 in
rear 1270 mm 50 in
Length 3886 mm 153 in
Manufacturer Alvis
Type S-4
8 valves total
2 valves per cylinder
Bore stroke 65.00mm 110.00mm
2.56 in 4.33 in
Bore/Stroke ratio 0.59
Displacement 1460 cc
(89.095 cu in)
Unitary capacity 365 cc/cylinder
Compression ratio 4.50:1
Fuel system 1 So carb
Aspiration Normal
Max. output 30.4 PS (30.0 bhp) (22.4 kW)
@3500 rpm
Coolant Water
Specific output 20.5 bhp/litre
0.34 bhp/cu in
Note: A value of -1 means that
the car cannot attain that speed.
0-60mph -1.00s
0-100km/h -1.00s
0-100mph -1.00s
Top speed 97 km/h
Engine location Front
Engine alignment Longitudinal
Suspension Front LA.SE.
Rear LA.SE.
Transmission 4M
Drive RWD
Top gear ratio 1.00
Final drive ratio 4.30