Specifications
BMW 3/20 PS (AM 1-4)
BMW 3/20 PS (AM 1-4)
Date of manufacture
1932 – 1934
Bodywork type(s)
Saloon, 2 & 4 Seater Cabriolet, Roadster and Van
Engine
Type Inline 4 cylinder
Capacity 782cc
Bore x stroke 56mm x 80mm
Power 20bhp @ 3500rpm
Compression 5.6:1
Carburettors 1, Solex 26 mm updraught
Valve design Overhead, 2 per cylinder
Valve gear Camshaft in block. Push rods, rockers, tappets and springs
Electrics 6 volt
Transmission
Clutch Dry single disc
Gearbox ratios
3 speed (AM1) 4 speed (AM4)
(1932-1933) (1933-1934)
1st 4.0:1 4.3:1
2nd 1.82:1 2.64:1
3rd 1.00:1 1.62:1
4th 1.00:1
Axle ratio
5.90 5.85
Synchromesh
None
Chassis
Frame Box section central backbone frame
Suspension Front: 1 transverse leaf spring only, friction dampers
Rear: Swing axle with 2 transverse leaf spring, friction dampers
Steering Worm
Brakes Four wheel cable
Handbrake, cable on rear wheels
Dimensions
Wheelbase 2150mm
Track front/rear 1100mm x 1100mm
Length/width 3200mm x 1420mm
Tyres 17 x 4.50in
General
Fuel capacity 25 litres
Max speed 50 mph
Number produced 7215
Club Mailing Address
BMW Historic Motor Club
Lower Norgrove,
Yarrington Road,
Alfrick,
Worcestershire.
WR6 5EX