In a world of jetskis where tribal knowledge trumps pretty much any other source of information, does anyone have any good sources as far as books, articles, manuals, etc. that scientifically explain performance extraction of 2-stroke engines? It does not need to be directly related to watercraft, although I realize that certain engine specifications are tailored for direct drive watercraft performance.
For example, the mystic art of engine porting. I often see posts discussing port duration/timing, blowdown, port geometry, among other things. I understand that the basic theory is to obtain enhanced air/fuel mixture flow characteristics by manipulating the OEM casting. From my understanding though, like I said before, seems to be based on years of trial and error and retained via tribal knowledge about what works well and how far you can take things. In my mind, all modern day engines have undergone serious CFD work to capture the flow regimes and patterns as the air fuel mix is delivered and how it performs within the combustion chamber. I could be wrong, but I would be surprised if any level of CFD has been analyzed on a 61x cylinder outside of what Yamaha has done of course. This leads to my next question without models, how apart from trial and error, is a well ported engine executed? How can you predict how a certain port shape or transfer timing will impact the end product?
I understand these are super loaded questions and no one necessarily wants to just give up secrets of the trade, which is more or less why I am asking for material to educate myself to understand better.
For example, the mystic art of engine porting. I often see posts discussing port duration/timing, blowdown, port geometry, among other things. I understand that the basic theory is to obtain enhanced air/fuel mixture flow characteristics by manipulating the OEM casting. From my understanding though, like I said before, seems to be based on years of trial and error and retained via tribal knowledge about what works well and how far you can take things. In my mind, all modern day engines have undergone serious CFD work to capture the flow regimes and patterns as the air fuel mix is delivered and how it performs within the combustion chamber. I could be wrong, but I would be surprised if any level of CFD has been analyzed on a 61x cylinder outside of what Yamaha has done of course. This leads to my next question without models, how apart from trial and error, is a well ported engine executed? How can you predict how a certain port shape or transfer timing will impact the end product?
I understand these are super loaded questions and no one necessarily wants to just give up secrets of the trade, which is more or less why I am asking for material to educate myself to understand better.
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