In 1924, the Sunbeam 14 was replaced by the 14/40. It used the 2121cc four cylinder overhead valve engine carried over from the 14 with magneto ignition. Carburation was by a Claudel Hobson MZP type.
Semi-elliptic springs were used at the front, with cantilevers at the back. The gearbox was a three speed unit with a right hand change. Four wheel brakes were fitted.
Bodies listed included: two and five seat tourers, sports model, coupe, saloon and Weymann saloon.
Production totalled around 2850.Sunbeam Models