Designed as the "RMH" just before the 1952
merger of Riley-parent, the Nuffield Organisation, with Austin
to form BMC, the Pathfinder was launched in 1953
and is considered to be the last "proper" Riley sedan. Although it shared its graceful body design with the Wolseley 6/90
which appeared in 1954
the Pathfinder retained its Riley twin cam, four cylinder engine and lowered stance which helped both looks and handling.
Powering the Pathfinder was Riley's 110 hp (82 kW) 2.5 liter 2443 cc twin-cam, straight-4 engine fitted with twin SU carburetors, an engine that had been designed way back in 1926. Performance was excellent, the Pathfinder capable of a top speed of nearly 100mph, making it very popular with British police constabularies.
The Pathfinder used a separate all steel chassis with coil spring rear (although this was changed to leaf springs towards the end of production), along with front torsion bar independent suspension. Braking was courtesy of 12 in (305 mm) Girling drums which had a servo fitted as standard, and from 1956
an overdrive gearbox became optional.
The spacious interior was well appointed in the usual Riley fashion (such as wood veneer fascia and leather seating) and could seat up to six people, thanks to its right hand, floor mounted gear change. Buyers could choose between two single seats and the optional full width bench seat, with the front corner of the seat squab contoured so as to accommodate the gear lever and allow seating for three.
The rear seat had a fold down centre armrest and leather covers were used. A heater was fitted as standard. The car was available in black, maroon, green, blue or grey finish. The gear lever was floor mounted by the driver's door, so drivers in right hand drive markets had to change gear with their right hand. The handbrake was operated by a lever under the centre of the dashboard in both bench and individual front seat versions.
The body was similar to the Wolseley 6/90
. Both cars were launched in 1953
, and both were designed by Morris' Gerald Palmer for the Nuffield Organisation before the merger (Palmer was chief engineer of BMC from 1952
). All Pathfinders featured the front independent suspension developed from the RMF, but the sophisticated Riley rear suspension was replaced by a conventional leaf spring type in the last few examples. An essential part of the location of the rear axle was a Panhard rod which on some early examples sheared on hard cornering resulting in the unfortunate 'Ditchfinder' nickname.
Pathfinder production ceased in 1957
when the inferior Riley 2.6 appeared.
STRICTLY CONFIDENTIAL and NOT FOR PUBLICATION BEFORE WEDNESDAY, 14TH OCTOBER 
THE RILEY PATHFINDER - A Fast, New Sports Saloon
The Riley "Pathfinder", announced by The Nuffield Organization today is an entirely new and spacious saloon of imaginative body design, having an engine which develops 102 b.h.p. and is capable of a maximum speed, under ideal conditions, of more than 100 m.p.h.
In order to achieve higher performance at all speeds the compression ratio of the successful 2443 c.c. o.h.v. engine with hemispherical head has been stepped up to 7.25 to 1. Riley enthusiasts will appreciate the siting of the gear shift lever on the floor on the extreme right-hand side (on the left on l.h.d. cars), a feature which in addition to its comfortable accessibility permits optional use of bucket or bench type seats.
Other refinements include the incorporation of the self-cancelling direction indicator switch on the horn ring, two speed self-parking screen wipers and black lighting for the instrument panel. The body is of all-steel construction with a turret-type top of immense strength.
The one-piece curved windscreen and curved rear light give unusual all round visibility and by mounting the 12½ gallon (59 liter) petrol tank forward of the boot and the spare wheel on a special platform under the boot floor, the amazing luggage capacity of 11 cu.ft, is provided. The boot door is counter-balanced and can thus be raised and lowered without effort.
A concealed petrol filler cap with a quick release is provided and the fuel is fed to twin S.U. carburetters by a rear mounted S.U. electric fuel pump of increased capacity. Full width bumpers with over-riders front and rear, and twin tail, stop and reverse lamps are fitted.
Rear suspension is by long coil springs with concentrically mounted hydraulic dampers, the axle being located by radius arms and a tranverse link. At the front the successful Riley "Torsionic" independent suspension system of torsion bars controlled by telescopic dampers is incorporated.
A Borg and Beck 10" single plate dry clutch transmits the power through a four speed, synchromesh gearbox and Hardy Spicer tubular propeller shaft to the semi-floating hypoid rear axle of 4.1 to 1 ratio.
Servo-assisted. Girling hydraulic fully-compensated brakes operate in 12 inch (30 cm.) drums and individual adjustment is provided, which simultaneously adjusts the handbrakes. The handbrake is of the pistol-grip type located under the facia. Instruments include a revolution indicator and temperature gauge in addition to the usual equipment.
Twin fog lamps, heater, map reading lamp, in-built windscreen washing and demisting equipment are also fitted as standard. The Pathfinder is available in the following colors:- Black (with maroon, green or biscuit upholstery) Maroon (with maroon or biscuit upholstery) Green (with green or biscuit upholstery) Blue (with grey upholstery) Grey (with maroon or grey upholstery).