Question 101Motor Plants - Assistant Engineer
70% to passWhich statement about diesel engine combustion is true?
ACombustion does not begin until the piston starts down on the power stroke.
BMaximum combustion pressure is reached before TDC.
CTurbulence in the cylinder causes a delay in ignition.
DMaximum cylinder firing pressure is not developed until the piston passes TDC.
AI Explanation
The correct answer is D) Maximum cylinder firing pressure is not developed until the piston passes TDC. This is correct because in a diesel engine, combustion begins before top dead center (TDC) and the maximum cylinder pressure is reached after the piston has passed TDC on the power stroke. The delay between ignition and maximum pressure is due to the combustion process taking time to fully develop. The other options are incorrect: A) is false because combustion begins before the power stroke, B) is false because maximum pressure is reached after TDC, and C) is false because turbulence actually helps the ignition and combustion process, not delays it.
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