If a four-stroke/cycle diesel engine is...

If a four-stroke/cycle diesel engine is...

Question 1 of 270705eccefa3bacbc34ba4d47d5d

If a four-stroke/cycle diesel engine is started by admitting high pressure air into the cylinders, the pistons receiving the charge of starting air must be __________.

Question 1 of 27070

Q

If a four-stroke/cycle diesel engine is started by admitting high pressure air into the cylinders, the pistons receiving the charge of starting air must be __________.

🔍 Key Concepts

• Four-stroke diesel cycle (intake, compression, power, exhaust) and what happens in each stroke • How starting air actually turns an engine that is not yet running • Piston and valve positions when air is admitted to create rotation

💭 Think About

• On which stroke is the cylinder already full of compressed, hot air versus mostly empty or open to the exhaust? • During which stroke would admitting high-pressure air push the piston in a way that actually helps turn the crankshaft, instead of just escaping out a valve? • Think about when both valves are closed and the piston can be forced down to produce torque on the crankshaft.

✅ Before You Answer

• Verify which stroke has both valves closed and the piston positioned so pressure can build • Check during which stroke the cylinder volume and piston direction will turn the crank effectively from a stop • Eliminate any strokes where intake or exhaust valves are open, since air would not be trapped to push the piston