Paper 1: Paper 2: A Standard-Triumph Family Car Engine-its Design History during a Decade

Abstract

The paper gives the history of the conception and design details of a mass-produced four-cylinder 803 cm³ engine, its redesign to 948 cm³ and the design of a twin-carburettor version. Finally a further redesign to increase the capacity to 1147 cm³ for both single- and twin-carburettor versions.

An initial appraisal was made of the type of unit required to power a small family saloon car.

Engine performance requirements were established from a performance curve of the vehicle obtained from frontal area aerodynamic coefficient, estimated weight, etc.

The configuration of the unit was fully investigated, the number and disposition of the cylinders, type of cooling, position of valves and type of valve gear were all explored, bearing in mind technical requirements, cost and ease of production and production plant requirements.

Having decided upon a four-cylinder in-line liquid-cooled unit, a detailed description is given of the reasons for the design configuration of the major components and the disposition of the ancillary equipment.

The need to extend the range of models of this vehicle brought about the first increase in capacity to 948 cm³ and design modifications are enumerated. A twin-carburettor version was a further requirement and design and development details are discussed.

With the introduction of a completely new design of motor car using this power unit, the road holding and general handling characteristics of the vehicle were so outstanding that improved engine performance became a necessity to match the above qualities.

The methods of increasing performance are discussed and the reasons given for the necessity to increase capacity. In view of already established transfer machinery for all major components, the minimum of change was essential and a history of the design and development of the unit is given. It is shown that careful study of existing equipment is vitally necessary when making extensive design changes. First designs made the minimum of change and only when test work showed shortcomings were further changes made. A series of designs and tests finally achieved a sound design giving excellent results from extended tests. This process established that all the modifications were vitally necessary to achieve the performance and reliability necessary for the engine to have a further period of production and enable progressive development to be successful.