Hand milling cutters/ spherical cutting for cylinder-head porting at home and is something a novice can accomplish to wake-up engine power. Material HSS - HRC 62±1. Specification kit - classic. Cutters ø 27,28,29,30,31,32,33; - mandrel L100 - 2ps.. mandrel L200 - 2ps. Cylinder head porting refers to the process of modifying the intake and exhaust ports of an internal combustion engine to improve their air flow. Cylinder heads, as manufactured, are usually suboptimal for racing applications due to being designed for maximum durability. The item "Ball Milling Cutters for cylinder head channels porting kit classic" is in sale since Monday, May 24, 2021. This item is in the category "eBay…