exhaust port question
 

Ok, I have made a observation and now I have questions about my observation.

After cracking open a couple or rx8 engines myself, and seeing other rx8 engines opened up by others, I have noticed something. On all of the engines I have examined/looked over, the narrow end of the exhaust ports are always packed in carbon.

So, what is the point of the narrow end of the exhaust port? The shallow tapper can't possibly flow much if any exhaust. It does not appear to effect port opening or closing. It is a great carbon trap, and I'm sure having the side seal sliding over that chunk of carbon extends seal life.

Is there a way to change the shape of the narrow end of the port to prevent carbon buildup.