[Frank_Zeller]

Good place to start.....to do any serious porting you need a carbide cutter and sizing valves. You want the throat to be a certain diameter. For a street Pontiac with 2.11 intake valves you use a 1.66-inch valve for sizing the bowl and throat. You insert the valve and keep slowly grinding away until it falls into the bowl all the way to the roof and part way into the throat. The next area is the sort turn radius. Then there is the side walls next to the sort turn radius….you widen and smooth. You don’t polish you want a ruff finish to help improve fuel are mixing on the intake. You do however polish and smooth the combustion chamber and the exhaust ports. On the exhaust side you widen the throat at the sort turn radius and smooth the short turn radius. Try to visualize a smooth flowing waterfall.

The main idea is to try to visualize the areas of restriction and open them up.