Riley 1½ Adelphi. (1936-39)

The most popular model on the 1½Litre chassis in its last three years was the Adelphi. A stylish new 6-light, 5 seater Saloon, which was offered across the Riley range, except for on the nine chassis. It was an immediate success, and eventually formed the basis of Nuffield's new 12hp Saloon. It is likely that a number of Adelphis were built after the receivers were called in in spring 1938, and possible that some were not first registered until 1939, but all later cars carry the 28A chassis number. In total somewhere between 1500 and 1800 were built, including a handful of Adelphi Sprites.
The body had a small trunk area with rear mounted spare wheel below a split rear screen. 1936 cars had traditional radiators, some 1937 cars have mesh grilles across the radiators and 1938 cars generally have the new chrome slat radiator shells. All cars had bumpers, those at the front recessed between the wing bulges, whilst the rear one dipped below the spare wheel. Cars could be single or duotone colour, with a variety of splits for the latter.

Chassis Types [Approx. Production Figures]: (S) 26A [720-880] / 27A [570-700] / 28A [150-220]


4cyl ohv
RAC Rating 11.9hp
Bore 69 Stroke 100
Capacity 1496 cc
51bhp at 4800rpm
Carburation 1 or 2 Zenith


Armstrong Siddeley Preselector 4-speed gearbox.
Top gear ratio 5.22:1
3rd G/r 7.39:1
2nd G/r 10.91:1
1st G/r 18.79:1
Reverse 23.91:1




Girling Mechanical rod with wedge operated shoes
13" drums


0-50mph 23.1secs
Max speed 73mph
Fuel Consumption 27mpg


Wheelbase 9'4.5" (aprx 2840mm)
Track 4'3" (aprx 1280mm)
Length 14'6.5" (aprx 4430mm)
Width 5'1.5" (aprx 1530mm)
Wheels Dunlop centre lock wire 3.0x18
Tyres 4.75x18
Fuel Tank 11.5 galls
Weight 25cwt


1936-7 £350; 1938 £375
Special Series +£27; Sprite +£48