i always use the stock closing edge and the stock closing edge bevel... then extend the opening down about 1/2 a cm

here is a picture of my housings i ported on a previous engine:
http://gallery.502streetscene.net/da...m/IMG_0021.JPG
http://gallery.502streetscene.net/da...m/IMG_0020.JPG

and here are my intake ports:
unfinished primary
http://gallery.502streetscene.net/da...m/IMG_0025.JPG

and an unfinished secondary
http://gallery.502streetscene.net/da...m/IMG_0054.JPG

How do you think my ports look? Does the closing edge need to be more laid back?

i dont like the idea of cutting into the stock closing edge at ALL. i would keep the compression stroke as long as possible... your bevel looks fine.

the engine already overlaps a little (at leased it looked like it to me when I had my half engine to play with, but hardly much at all), so going up is just going to make things worse rather than better. So no up, but oh-ya down

I did not go up a whole lot just to the top of the bevel. I will have to remember that the next time I do some port work. It has been a learning expierence.

Thank you everyone who gave me advice.

Don't open the exhaust early. It's bad all around the board. If anything, close later; the opposite of intake porting -- open early, close the same.

B

All this talk of port opening / closing timing is half the story. Ever wonder what real flowbench numbers are for certain port shapes?

http://www.yawpower.com/Flow%20Testing.html

well the engine is back together and running, it smokes a little on startup but not realy any other time that I can tell It does not seem to be burning much oil. I will be pulling the plugs in a few days to check them.