Question 157Motor Plants - 1st Asst/Chief70% to pass
A loop or cross scavenged engine utilizes the motion of its pistons and a turbocharger to provide scavenging air. Which of the listed mechanical designs prevents the air under the pistons from being pumped back through the scavenge ports during the piston power stroke?
AI Explanation
The correct answer is C) Length of the piston skirt.
In a loop or cross scavenged engine, the length of the piston skirt prevents the air under the pistons from being pumped back through the scavenge ports during the piston power stroke. The piston skirt acts as a barrier, sealing off the scavenge ports and preventing the reverse flow of air, which is essential for the proper scavenging of the cylinder.
The other options are incorrect because: A) Positive pressure from the blower is responsible for providing the scavenging air, not preventing the reverse flow; B) Masked intake ports are not relevant to the scavenging process; and D) Lower liner seals do not directly prevent the air from being pumped back through the scavenge ports.
Related Questions
#155 Which of the following devices will increase the power output of a diesel engine without increasing its frictional load? #156 Clearance volume scavenging in a turbocharged, four-stroke cycle diesel engine is accomplished _______________.#158 Maintaining the lowest possible scavenging air temperature at all times is not recommended due to the possibility of the _______________.#159 Which of the couplings listed is normally not repairable, and is usually replaced if completely damaged? #160 When installing the bearing cap on the device shown in the illustration, which of the precautions listed must be observed? Illustration MO-0121