[Bob Bidonde]

Hi Brent! The sand casting process is not a precision one, and it was my experience that my sand cast designs were at the mercy of the pattern maker's best effort and the actual casting process. Sample castings were destructively measured and dimensions feed back to the engineer for structural and functional analysis. If found acceptable, the engineering drawing would be revised to reflect the actual dimensions. Did Ford do this???

I recommend that you survey some Model "A"engines that have been cutaway, and check their cylinders for wall thickness and bore size to analize their original wall thicknesses. The limiting walls have to be those between Cylinders 1&2 and Cylinders 3&4.

I am assuming that Ford engineers did a structural stress analysis, a thermal stress analysis and a thermodynamic heat transfer analysis to determine their 0.060" oversize piston is serviceable. So as a business man, I would not recommend boring cylinders more than 0.060" as Ford limited by service piston size.