Who is right about the impact of excessive cylinder head resurfacing on pushrod engine geometry?

Excessive cylinder head resurfacing can significantly impact pushrod engine geometry. When the surface of the cylinder head is machined multiple times, it reduces the overall thickness of the head. This change can affect the relationship between components in the engine, including the pushrods, rocker arms, and overall valve timing.

Both technicians likely provide valid points regarding how resurfacing alters the intended alignment and vertical movement of the pushrods within the engine. Adjustments to the height of the cylinder head can lead to changes in the pushrod length or even modifications to the valvetrain angles. Such alterations can result in unwanted effects like increased wear or failure of components and can adversely affect engine performance.

Understanding this impact is crucial for maintaining optimal engine operation and longevity, as proper geometry ensures that the engine runs smoothly, efficiently, and without excessive wear or additional stress on components.