Alignment of the cylinder head is a concern for two reasons related to air flow around the intake valve.
1) Centering the valves in the bore will help unshroud the valves around the sides. Centering will also reduce or alleviate the ridge formed by the combustion chamber extending beyond the cylinder wall.
2)The area above the intake valve in the photo (spark plug side of the combustion chamber) is the high flow side of the valve. This area is very important for unshrouding and blending for good air flow. As shown in the photo, the size of this area has been reduced by placing the valve center line above the cylinder bore centers. Positioning the valves centers above the bore center line as has been done is more disadvantageous for good air flow than positioning the valve centers below the bore center line. Relocating the cylinder head on the block would be a pain. Significant performance increase may result, so that's why I asked. And, I agree with the statements above by others on the compromises to be evaluated concerning effort, cost, and performance results.
Larry (Twisted Six), as you stated that this has been performed in the past, do you recall the performance results of centering the cylinder head in the cylinder bore?
