Tim:
I got the chart. Can't open it yet. I don't have Excel. I'll have to download a trial version from Microsoft.

FlyJoe540:
I appreciate that info. I knew that there was a risk of opening the exhaust up too much and uncovering the bottom of the piston skirt when its at TDC. I agree that it would ruin the engine. Opening the bottom side of the case to exhaust gasses is going to completely ruin intake suction.
But, I have a question:
Why are you taking material off the bottom of the exhaust port? I always thought that you were supposed to only take material off the top.??

I got 128* exhaust duration when I checked it last night. [] I guess I'll open it up a bit. My local friend has a lathe. I might take it to him and have the cylinder knocked down a little to increase the compression ratio.

Whats the minumum squish band? .15? .20?

If I knock the jug down a bit, then it seams logical to me that I'd want to take a bit off the top of the exhaust port to at least get it back to 128* duration.