Performance Improvement of a Four-Cylinder Gasoline Engine with Continuous Variable Valve Timing Mechanism Using a Three-Dimensional Cam

Variable valve timing has become an important feature of automotive engines as part of the search for a better compromise between performance, economy and emissions. This paper describes the Rover VVC system and has been written in two parts. The first part covers the initial feasibility study, the selection of the mechanism and the unique features evolved to suit the K16 engine. The second part covers the detailed mechanical layout, the development work undertaken and the performance obtained.

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Development of a high performance lean burn engine with a 3-stage variable valve timing mechanism Aruto Hayashi, Yusuke Wada (Honda R&D Co., Ltd., Tochigi R&D Center)

JSAE Review ◽

10.1016/s0389-4304(96)80488-7 ◽

1996 ◽

Vol 17 (4) ◽

pp. 435

Keyword(s):

High Performance ◽

Variable Valve Timing ◽

Valve Timing ◽

Lean Burn ◽

Timing Mechanism ◽

Variable Valve

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FEASIBILITY OF BACKFIRE CONTROL AND PERFORMANCE USING CHANGES OF VALVE OVERLAP PERIOD FOR A HYDROGEN-FUELED ENGINE WITH EXTERNAL MIXTURE

Science and Technology Development Journal ◽

10.32508/stdj.v12i14.2342 ◽

2009 ◽

Vol 12 (14) ◽

pp. 77-85

Author(s):

Cong Thanh Huynh ◽

Kang Joon-Kyoung ◽

Noh Ki-Cholo ◽

Lee Jong-Tai ◽

Mai Xuan Pham

Keyword(s):

High Efficiency ◽

Engine Performance ◽

Continuous Variable ◽

Variable Valve Timing ◽

Valve Timing ◽

Performance Loss ◽

Wide Range ◽

And Performance ◽

Variable Valve ◽

Valve Overlap

The development of a hydrogen-fueled engine using an external mixture (e.g., using port injection) with high efficiency and high power is dependent on the control of backfire. This work has developed a method to control backfire by reducing the valve overlap period. For this goal, a single-cylinder hydrogen-fueled research engine with a mechanical continuous variable valve timing (MCVVT) system was developed. This facility provides a wide range of valve overlap periods that can be continuously and independently varied during firing operation. In experiments, the behavior of backfire occurrence and engine performance are determined as functions of the valve overlap period for fuel-air equivalence ratios between 0.25 and 1.2. The results showed that the research engine with the MCVVT system has similar performance to a conventional engine, and is especially effective in controlling the valve overlap period. The obtained results demonstrate that decreasing the valve overlap period may be one of the methods for controlling backfire in a H engine. Also, a method for compensating performance loss due to shortened valve overlap period is recommended.

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