Development of CNG Engine with Variable Valve Timing Electronic Control 2007-01-3615
Honda has developed the Compressed Natural Gas (CNG) engine with Variable Valve Timing Electronic Control. This new engine was designed to further enhance power and efficiency: increased engine displacement and the use of a variable-length air intake manifold have achieved a 15% enhancement in power. In addition, engine fuel consumption has been reduced by 5% through a combination of reduced pumping loss due to inlet valve control for delayed closure, and charging stroke injection timing that harnesses the properties of gaseous fuel. As a countermeasure for tail pipe emissions, an exhaust manifold integrated with the cylinder head and a close coupled two bed catalyst have been used. As a result, the use of precious metals has been reduced by approximately 30%, and the vehicle with the new engine complies with CARB's AT-PZEV standard.