West bend 820 porting question

[Kevin Davis]

Here is a picture of a West Bend 820 ( that I was told, was ported by Dave Bonbright). Could someone educate me .In the picture on the inside of the cylinder there is some port work that doesn't appear to be complete ).What is its purpose ?

[steve welte]

Those are the 2 boost ports cut into the cyl. Your piston needs to have 2 holes that line up to feed those.