This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Improvement of Two-Stroke Engine Performance with the Yamaha Power Valve System (YPVS)
Annotation ability available
Sector:
Language:
English
Abstract
In two-stroke engines, the exhaust port timing has a great effect on engine performance characteristics. If the exhaust port timing can be varied in response to variations in the engine speed, an extensive improvement of performance can be realized.
The Yamaha Power Valve System (YPVS) increases engine output with a valve which operates in the exhaust passage; this valve controls exhaust port timing in response to engine speed, despite the extremely high thermal load encountered in the exhaust passage. This literature deals with the construction and operation principles of YPVS and its effect on the increase of engine output. Also discussed is a series of tests and measurements made on the delivery ratio and trapping efficiency in order to elucidate why engine output is increased.
Recommended Content
Topic
Citation
Hata, N. and lio, T., "Improvement of Two-Stroke Engine Performance with the Yamaha Power Valve System (YPVS)," SAE Technical Paper 810922, 1981, https://doi.org/10.4271/810922.Also In
References
- Tsuchiya K. Hirano S. “Characteristics of 2-Stroke Motorcycle Exhaust HC Emission and Effect of Air-Fuel Ratio and Ignition Timing” SAE Paper 750908
- Gomi T. “Gasoline Engine” Automobile Engineering Completion 4 Sankaido
- Shimamoto Y. “Availability of Induction and Exhaust Pipe Effect (1)” Internal Combustion Engines 10 108 3 1971
- Shimamoto Y. “Availability of Induction and Exhaust Pipe Effect (2)” Internal Combustion Engines 10 111 6 1971