The formula for figuring out the cubic inches of a engine is as follows:

       Bore x Bore x Stroke x .7854 x # of cylinders

For example, we will use the 318 with a standard bore of 3.91".  The stroke is 3.31".

                     3.91 x 3.91=15.2881
                15.2881 x 3.31=50.603611
           50.603611 x .7854=39.7440760794
          39.7440760794 x 8=317.9526086352

If we round up just a bit, we come up with our beloved 318.  This works for all engines, and is a accurate and easy way to figure out the cubes of those stroker motors.

                                                    Jeff