Which engine components are the last to receive oil?

The valve train components are indeed the last to receive oil in an engine system. This is primarily due to the layout and flow dynamics of engine oil distribution. When the engine is running, oil is typically pumped through a network of galleries and passages, starting from the oil pump, which is located near the sump or oil pan.

As oil travels through these passages, it first lubricates parts that are situated low in the engine where the oil is initially gathered after it has cycled through the system. This includes the crankshaft bearings and piston components, which receive oil relatively early. However, the valve train, which includes components like lifters, camshafts, and pushrods, is positioned higher up in the engine assembly. Because of this arrangement, it generally takes longer for oil to reach these higher components after being pumped.

This delay is further exacerbated during engine start-up when oil needs to first accumulate in the lower areas. Therefore, the valve train often ends up being the last to receive oil, making it critical for engine designs to ensure adequate lubrication reaches these components to prevent wear and maintain performance.