A Universal Test Engine for Combustion Research

The original Ricardo E6 engine which has given good service over many years has been supplemented by the more versatile, high speed Hydra engine. The design offers considerable flexibility for incorporating variations in bore, stroke, and combustion chamber design - diesel gasoline, and stratified charge.

The paper describes the design of the standard Hydra engines and gives typical performance data in a number of builds. Specimen combustion photographs taken through a transparent piston crown are also given. The paper mentions the problems arising from the alignment of the engine/dynamometer connecting shaft, and describes experience with an improved blowby meter.