| Porting can be done at home with a rotary tool that uses the common 1/8" diameter shank bits. WalMart and Amazon sells a good one with 3 speeds and 1" diameter cutting wheels which can be trimmed down to smaller diameters as need be. Just be sure to not have your eyes in the path of metal bits being thrown outward away from the wheel. Amazon Black & Decker WalMart Black & Decker Dremel 409 Cut-off Wheel, 15/16 " (23.8 mm) diameter from Amazon dremel bits from mcmaster.com : 1/4" cylinder bit SA-51 $9.50, 1/4" ball bit SD-51 $9.50  After you grind off metal from the port sides then you need to round off the sharp edges with a hand file like these from Amazon. For the top edge of the exhaust port file a bevel there of 10 degrees from the cylinder surface so the rings can gently be pushed back to where they should be as the piston rises.  Accurate measurement of port heights can be done with a digital caliper, also from WalMart and Amazon, by using its "tail".  Click Here for my page on how to find the port durations in the most accurate way. |