Recent Developments in the Nsu Wankel Engine

Abstract

Eight years have passed since the first rotary engine system NSU Wankel showed positive torque on the test bench at Neckarsulm. At present four different types are in production, although the production rate is still comparatively low. Sixteen companies in Europe, America and Asia are pushing the development whereby a close and friendly co-operation is assisting progress. This paper deals only with the development done at NSU Motorenwerke, Neckarsulm, as naturally the other licencees do not want to disclose their plans before they have reached a final stage. It may be remembered that the size of the rotary engines under development covers a wide range between 3 and 800 h.p. Furthermore, a wide field of applications is visualized, covering lawn-mower engines, chain-saw units, automotive engines, stationary engines for all kinds of purposes and boat drives. The most attractive type, from a production viewpoint, is the automotive engine which at the same time presents the most technical difficulties. This type of engine requires not only low production cost but high durability and a lot of specific features such as regular idling, high torque at low speed, smooth operation within the complete load and power field and cold starting possibility. NSU has concentrated development activities on two different systems of rotary engines, namely a series of air-cooled engines and two types of water-cooled units which are identical in their main components.