When heavy machining is performed on a V8 engine, how should the heads be machined?

When heavy machining is performed on a V8 engine, the heads should be machined based on a multiple that depends on the angle of the head. This is crucial because the alignment and angles of both the cylinder heads and the engine block are integral to maintaining proper sealing and combustion efficiency.

Machining the heads to an appropriate angle ensures that the mating surfaces maintain the necessary geometric relationships to prevent issues such as warping, misalignment, or improper sealing. Specifically, the angles of the heads can affect how the combustion chamber is shaped, influencing both airflow and efficiency.

Additionally, the adjustment is often necessary to accommodate for the change in volume and compression ratio that results from machining the block, which can be different based on the specific design and intended performance characteristics of the engine. This is why understanding the relationship between the head angle and the amount of material removed is essential in engine machining practices.