Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Plus 4 CX - Initial Thoughts

The article in the link has the diagram. The scroll is the chamber the gases go thorugh see picture below. So it isn't like a Rootes blower it is effectively a reversed centrifugal pump with two inlets.

Interestingly the Lotus one had 2 nozzles rather than what look like slots.