Heads are the first jet washed in a high-pressure spray cabinet to remove oil and dirt, then glass beaded to remove carbon. Next, they are checked by magnafluxing, (cast iron only) or pressure testing. They are visually inspected for defects that would make them unusable. Valve guides and seats are removed as needed for porting. Port development is accomplished using a superflow 600 flow bench with a computer recording all flow measurements. Many things are considered when designing a cylinder head Port; air flow is only one of the things to think about. Another major concern is port wall thickness.
Anyone can get a head to produce high flow numbers, but if doing so leaves the port wall to thin the casting will crack. High-performance Diesel heads are more prone to crack because of the thermal shock experienced by excessive intermittent or long-term exhaust temperatures. The porting is then performed using a new 5 Axis CNC Cylinder Head Porting Machine with CAD/CAM software specifically designed for cylinder head porting. CNC porting brings unparalleled accuracy to head porting with each port flowing the same. This helps balance the power that each cylinder produces, making tuning easier.