 The gasket opening is scribed onto the head. The chamber to the right has been bowl blended. For optimum flow, especially with our blower motor where we have a lot of forced induction, the head is opened up and smoothed to create better flow and cylinder swirling. |
Sehr Performance is working on the heads now. The Brodix Track-1 heads came unfinished. Sehr has finished the inside diameter of the valve guides to .001 clearance as Brodix recommends using a reamer. 
After finishing the valve guides he started rough cutting the radiused (for optimum flow) 3-angle cuts for the valves.
The top angle is 30-degrees and the radius is 45-degrees. There is not such an abrupt turn when you radius the cuts and so flow is increased – resulting in better performance. This is still considered a 3-angle valve job. 
The aluminum is then rough cut out with a Bowl Hawg to remove the excess material and to keep the material in concentric with the valve seat. You can see the masking tape on the Bowl Hawg. This reduces chatter of the bit giving some vibration dampening.
Here you see the results of the Bowl Hawg… what a name! Glad my parents didn't think of that one.