Technical Paper
Using the 2nd Law of Thermodynamics to Optimize Variable Valve Timing for Maximizing Torque in a Throttled SI Engine
1999-03-01
1999-01-0328
Previous investigations have demonstrated that improvements in gasoline engine performance (engine efficiency, power, exhaust emissions, engine braking, and usable engine speed range) can be accomplished if the valve timing are variable. Because of the difficulties of providing a variable valve timing (VVT) mechanism with acceptable cost, durability and reliability, very few automotive engines in normal production have been equipped till now with variable valve timing. However, owing to recent technology developments associated with electromagnetic and hydraulic valve control, and owing to recent progresses in microprocessor utilization, the application of VVT in the near future is quite feasible. In this work valve timing strategies for maximizing engine torque in terms of the intake closing and exhaust opening timings of a commercial throttled SI engine are studied.
