Skip to main content

Heavy Duty Equipment Technician Red Seal Exam Prep · Question

During the exhaust stroke of a 4-stroke cycle diesel engine, the piston travels from BDC to TDC, expelling spent gases. Which valve(s) should be open during this period?

During the main duration of the exhaust stroke, the piston rises from BDC to TDC while the exhaust valve is open. This allows the spent combustion gases to be p

Start free practice for Heavy Duty Equipment Technician Red Seal Exam Prep

300 questions · no signup required · 40 free questions per day

Start Practice →

Question: During the exhaust stroke of a 4-stroke cycle diesel engine, the piston travels from BDC to TDC, expelling spent gases. Which valve(s) should be open during this period?

Answer options: ✅ The exhaust valve is open, and the intake valve is closed.

  • Both the intake and exhaust valves are open during valve overlap.
  • The intake valve is open, and the exhaust valve is closed.
  • Both the intake and exhaust valves are closed.

Correct answer: The exhaust valve is open, and the intake valve is closed.

Explanation: During the main duration of the exhaust stroke, the piston rises from BDC to TDC while the exhaust valve is open. This allows the spent combustion gases to be pushed out of the cylinder into the exhaust manifold. The intake valve remains closed to prevent exhaust gases from entering the intake system; valve overlap only occurs briefly at the end of the exhaust and beginning of intake stroke.

Start free practice for Heavy Duty Equipment Technician Red Seal Exam Prep

300 questions · no signup required · 40 free questions per day

Start Practice →

More about Heavy Duty Equipment Technician Red Seal Exam Prep

Related Questions

More for Heavy Duty Equipment Technician Red Seal Exam Prep candidates

Ready to practice?

Free, no signup required. Build a wrong-question list as you go.

Start Free Heavy Duty Equipment Technician Red Seal Exam Prep Practice →

Related courses

Other Canadian certifications candidates often prepare for alongside this one.