🔍 Key Concepts

• Difference between two-stroke and four-stroke diesel engine cycles • Relationship between crankshaft revolutions and power strokes in each type of engine • What a power impulse (power stroke) actually is in the engine cycle

💭 Think About

• First, picture one full operating cycle of a two-stroke diesel: how many strokes does the piston make and what happens on each stroke? • Compare that to a four-stroke engine: in a four-stroke, how many crankshaft revolutions are needed before the same cylinder fires again? • Ask yourself: in a two-stroke engine, does the cylinder produce power on every revolution of the crankshaft, or only every second revolution?

✅ Before You Answer

• Make sure you clearly distinguish two-stroke from four-stroke timing – don’t mix the two up. • Confirm how many piston strokes occur per crankshaft revolution in a simple crank-slider mechanism. • Verify at what point in the piston’s travel (upstroke or downstroke) the power impulse occurs in a two-stroke diesel.