Engine - Armstrong Siddeley Mamba
The Mamba has virtually a straight-through air flow system, its diameter (less than 30ins measured over the cowling) is remarkably small and the frontal area only about 30% of that of an equivalent piston engine. A 500-hour test was successfully carried out in 1948. The Mamba has a 10-stage axial flow compressor supplying 6 combustion chambers and a two-stage turbine.
One of the main features of the engine is a pre-heating of the fuel/air mixture by directing the fuel upstream against the primary air flow, this can readily be seen on the engine. The reduction gear is also a remarkably compact unit of the planetary type and can be seen in the propeller spinner.
The Mamba engine was used on the Avro Athena and Boulton Paul Balliol prototype.