Engine Repair Final Exam 2024 Actual Questions and Answers Graded A+

Which of the following is not a common engine construction material? a. Aluminum b. Carbon fiber c. Cast iron d. Magnesium - b. Carbon fiber Technician A says engines can be classified by their number of operating cycles. Technician B says engines are classified by the type of valvetrain used. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A or B - c. Both A and B How many degrees of crankshaft rotation are required to complete one complete combustion cycle? a. 180 b. 360 c. 540 d. 720 - d. 720 Technician A says most engines rotate in the clockwise direction. Technician B says most engines rotate in the counterclockwise direction. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A or B - b. Technician B All of the following statements about compression ratio or correct except: a. Increased compression ratios require high-octane fuel b. Carbon deposits decrease compression ratio c. Compression ratio is based on piston stroke d. Increasing compression ratio can increase power output - b. Carbon deposits decrease compression ratio Technician A says the Atkinson cycle reduces displacement and compression. Technician B says the Atkinson cycle shortens the compression stroke. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A or B - c. Both A and B All of the following are advantages of diesel engines except: a. Diesel engines use less fuel than gasoline engines b. Improved cold-weather starting capability c. Increased durability compared to gasoline engines d. Increased combustion efficiency - b. Improved cold weather starting capability Technician A says in a series hybrid, the electric motor drives the wheels. Technician B says in a series hybrid, the wheels are driven by the internal combustion engine only. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A or B - a. Technician A Which of the following is not a high-efficiency low-emission engine design? a. Stratified charge engines b. Rotary engines c. Homogenous charge engines d. Variable compression engines - b. Rotary engines A four-cylinder late model engine has low cranking dry and wet compression readings on one cylinder. Technician A says a worn camshaft lobe could be the cause. Technician B says worn valve seats could be the cause. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A or B - d. Neither A or B Which test can be used to diagnose a head gasket leak? a. Cylinder power balance test b. Running compression test c. Cylinder leakage test d. Vacuum test - c. Cylinder leakage test Vacuum gauge readings are being discussed. Technician A says a low but steady vacuum reading indicates a timing problem. Technician B says a low but steady reading indicates a restricted exhaust system. Who is correct? a. Technician A b. Technician B c. Both A and B d. Neither A or B - a. Technician A