Development of New 3.5 L V6 Gasoline Direct Injection Engine 2023-32-0073
A 3.5-L natural aspiration engine was developed to enhance the environmental performance of V6 engines to be used in Honda’s North American market.
This engine changes from the single overhead cam architecture for the cylinder head found in the previous engine to a double overhead cam architecture and adopted variable timing control intake and exhaust variable cylinder management for the valve system. This increased the degree of freedom in setting valve timing across the operating range compared to the past, increased the intake air volume in the high-load range, and realized reduction of pumping loss under low and medium load.
The intake port, combustion chamber, and piston shape related to combustion have been newly designed to enhance in-cylinder flow. In addition, while following the cooling structure of previous engine, water channels were installed between the exhaust valves and between the cylinder bores to enhance the cooling performance of the combustion chamber. These improvements have resulted in improved thermal efficiency while achieving the same or higher power performance of the previous engine.
High fuel pressure and injectors with reduced nozzle hole size were adopted for the fuel system in order to enhance emission performance. This in combination with multistage injection control realized atomization of the spray and shorter spray penetration distance. A vehicle equipped with this engine achieved LEV III and SULEV 30 standards as well as particulate matter of 1 mg/mile.
Methods used to reduce engine noise due to rapid combustion were increasing the stiffness of the intake manifold and adopting a mounting layout on top of the engine for the intake system, which functions as an engine cover. These methods achieved engine noise level on a par with previous engine.
