🔍 Key Concepts

• Examine the illustration carefully and match each choice to an actual, visible part of the engine (don’t assume parts that are not clearly shown). • Recall the speed relationship between the camshaft and crankshaft in a four-stroke diesel engine. • Think about where crankcase explosion relief doors, oil filters, and electric starters are normally located on real engines and whether they appear in this section view.

💭 Think About

• For each answer choice, ask yourself: can I positively identify this feature in the drawing, or am I guessing based on what a typical engine might have? • If the engine is a four-stroke, what must be true about how often the camshaft makes a revolution compared to the crankshaft to open valves at the correct times? • Look closely along the sides of the crankcase and outside the engine block—do you actually see explosion doors, an oil filter, or a starter motor in this cutaway?

✅ Before You Answer

• Visually confirm any claimed component (relief doors, oil filter, starter, governor linkage) in the illustration itself; if you can’t see it, treat that choice with suspicion. • Review the basic four-stroke cycle (intake, compression, power, exhaust) and how many crankshaft revolutions it takes, then relate that to camshaft speed. • Before choosing, eliminate any option that contradicts standard four-stroke engine timing or that refers to parts not clearly depicted in the drawing.