Development of New 3.5 L V6 Turbocharged Gasoline Direct Injection Engine 2016-01-1012

This paper introduces the newly developed super sports car engine mounted in the new model NSX. A super sports car engine was newly developed to satisfy the high power performance required by the body package. Higher power and compactness were simultaneously achieved by selecting an engine displacement of 3.5 L and by using a V6 layout and a turbocharger. This enabled to mount a power train that combines a hybrid motor with a newly developed transmission in the rear of the body. The lubrication system uses a dry sump system capable of maintaining reliable lubrication in all possible super sports car driving scenarios. The combustion system uses high tumble-flow ports, a direct injection and a port injection system that increase power performance and thermal efficiency, emission reduction.

To support the increased heat load due to higher power, a 3-piece water jacket is used around the combustion chamber and the exhaust ports. This optimized the cooling water flow to each part of the cylinder head, enabling to simultaneously suppress knock and cool the exhaust ports.

The cylinder bores have a Fe spray coating that enabled a reduction in weight while enhancing cooling.

This spray-coated liner can form a film that is both harder and thinner than typical steel liners and aluminum liners. This suppressed the increase in the bore pitch, and allowed positioning of cooling water channels between the bores.