One litre twin chamber Pivotal Engine applications - Pivotal Engineering Ltd, Christchurch, New Zealand

This concept engine is still at an early stage of development and therefore refinement of each aspect and component will show sizable gains in power density, efficiency, emissions reductions and longevity. The performance of this one litre twin chamber demonstration engine is very encouraging.

HC readings are between 1,400 and 2,800 ppm through the rpm range. NO readings peek at 450ppm at full load. These readings are recorded using an Automotive Diagnostics digital gas emission analyzer.

Due to its modular construction, this engine offers greater diversity and cost savings. Each chamber is assembled from common, easily manufactured components and this makes it possible to build engines of different size and configuration from a single unit. A duplication of just our current demonstration engine would provide a four chamber, two litre engine with 224 NM of torque and 144 kW of power in a compact 90kg package (better than 1.5 kW per kg).

This engine features a piston with cooling water circulating through the piston itself, entering and leaving the piston via the pivot shaft. A direct lubrication system controlled by the ECU results in an extremely low rate of oil usage. Down to a ration of 300/1 petrol at this point.

The fuel is injected using Bosch automotive injectors via the transfer ports. This system has worked well during the early concept development stage with the EMS controlling the timing of delivery to minimise fuel loss at part load. The position of the transfer ports and the full loop displacement scavenge both assist in providing an accurate exchange of gasses with a minimum of exhaust gas contamination.

We are currently integrating a direct chamber fuel delivery system which will further lower emissions and improve efficiency.

This engine was assembled to demonstrate the 'Pivotal' engine concept to manufacturers who are looking for a new and better potion. We consider that the future potential of this type of engine will be evident when engineers see it perform and study the design features which make it unique.

« Back ::