A four-stroke cycle auxiliary diesel engine fuel cam has shifted from its original position during maintenance. To ensure correct timing of the fuel pump, the intake and exhaust valves should be in what position when approaching top dead center for injection?
• Four-stroke diesel cycle: intake, compression, power, exhaust • Relationship between piston position (top dead center) and valve positions • When in the cycle fuel injection normally occurs on a four-stroke diesel
• Think about during which stroke fuel injection occurs in a four-stroke diesel and where the piston is at that moment. • At the moment just before injection, should the cylinder be sealed for compression, or should one of the valves still be open? Why? • Walk through the valve positions at the end of the intake stroke, during the compression stroke, and at the start of the power stroke.
• Confirm at which stroke injection normally begins in a four-stroke diesel engine. • For that stroke, verify whether the intake valve should be open or closed. • For that same instant, verify whether the exhaust valve should be open or closed so proper compression and combustion can occur.
No comments yet
Be the first to share your thoughts!