Joe,

I just ran the numbers from the manuals on the YS site and they come out correctly. What formula are you using? Are you sure you are doing the conversion from cubic MM to cubic inches correctly?

My calculations on the 1.60 come out to 1.6066887577 cubic inches and the 1.70 comes out to 1.7064142668 cubic inches.

Pete

friends don't let friends drink and derive.........a bit of math humor.......