Boyesen ports

[endurohero]

Is there a rule of thumb for the total erea of these ports ie 60cc need them this big and no bigger and so on.Is the theory behind these ports to shorten the intake track by sending air/fuel directly to the transfer tunnels instead of having to go below the piston and then up?Would aiming these ports at any particular angle make any difference?If the flow of the port window is maxed out at a particular rpm how would craming more air fuel in the tunnel achieve anything?Are there any enginering papers written on manipulation of boundry layer thinknesses?

 

[Rich Rohrich]

These two papers should provide plenty of food for thought in this area. :thumb: You can buy them directly from the SAE or read them at any good engineering library (like my living room :) )


SAE paper # 1999-01-3333
The Relationship Between Port Shape and Engine Performance for Two-Stroke Engines
AUTHOR(S):
Hisatoshi Kinoshida- Yamaha Motor Co., Ltd.
Yuh Motoyama - Yamaha Motor Co., Ltd.

SAE paper # 980764
Some Fundamental Aspects of the Discharge Coefficients of Cylinder Porting and Ducting Restrictions
AUTHOR(S):
Gordon P. Blair - Queen'S Univ.
Denzell Mcburney - Queen'S Univ.
Paul Mcdonald - Queen'S Univ.
Patricia Mckernan - Queen'S Univ.
Robert Fleck - Queen'S Univ. of Belfast

Or you can really go to school and get :
Design and Simulation of Two-Stroke Engines

AUTHOR:Gordon P. Blair


Design and Simulation of Two-Stroke Engines discusses principles of automotive design which are specific to this engine type. The book includes new theory, which the author has developed, that has not been published before, particularly in relation to two-stroke engines, including: unsteady gas flow in engine ducting; scavenging flow within the cylinder; two-zone combustion to compute exhaust emissions; computation of intake and exhaust sound pressure levels; discharge coefficients or ports and valves. Design and Simulation of Two-Stroke Engines is a unique hands-on information source. The author, having designed and developed many two-stroke engines, offers practical and empirical assistance to the engine designer on an array of topics ranging from porting layout, to combustion chamber profile, to tuned exhaust pipes. The information presented extends from the most fundamental theory to pragmatic design, development, and experimental testing issues.

Chapters cover: Introduction to the Two-Stroke Engine; Gas Flow through Two-Stroke Engines; Scavenging the Two-Stroke Engine; Combustion in Two-Stroke Engines; Computer Modeling of Engines; Empirical Assistance for the Designer; Reduction of Fuel Consumption and Exhaust Emissions; and Reduction of Noise Emission from Two-Stroke Engines.

Design and Simulation of Two-Stroke Engines explains in great detail the theoretical fundamentals, as newly developed by the author, of unsteady gas flow, combustion, and scavenging. This has resulted in two engine simulation models and a set of computer software programs which are described and demonstrated in the book. The models are sold separately, and the book is available with or without the companion set of software programs.

About the Author
A world-renowned expert on the two-stroke cycle engine, Dr. Gordon P. Blair is currently Professor of Mechanical Engineering at the Queen's University of Belfast. Professor Blair has served the University as Dean of the Faculty of Engineering and as Pro-Vice-Chancellor. In addition to his teaching and research work at the University. Professor Blair has been a consultant for many well-known companies such as Ford, General Motors, Mercury Marine, Volvo, and Yamaha. He has been named a Fellow of the Society of Automotive Engineers, the Institution of Mechanical Engineers, and the Royal Academy of Engineering. Professor Blair has been recognized by Her Majesty The Queen by the award of a CBE (Commander of the Order of the British Empire).

 

[LJW]

Go to www.uspto.gov and search for patent number 4,202,299.
The best explanation you are going to find, words and images from the MAN himself.

 

[endurohero]

Thank you very much . I just recieved the two sae papers and have given them the once over and I have already had 4 major questions answerd buy facts not bs.(i hated school, but now that i am old learning stuff is very cool.)