86 Diesel Engine Technology Copyright Goodheart-Willcox Co., Inc. 1. Technician A says the distance from the centerline of the crankshaft to the centerline of a connecting rod journal is equal to half the total travel (stroke) of the piston. Technician B says that this distance equals the total stroke of the piston. Who is right? (A) A only. (B) B only. (C) Both A & B. (D) Neither A nor B. 2. The _______ stores some of the kinetic or motion energy of the power strokes and uses its momentum to push the pistons back past top dead center during the exhaust and compression stroke(s). (A) vibration damper (B) flywheel (C) crankshaft (D) internal balancer 3. Technician A says that the crankshaft in a two-cycle engine will make two revolutions during each com- plete combustion cycle, while the camshaft will make only one. Technician B says this is true of four-cycle engines, not two-cycle engines and that in a two- cycle engine both the camshaft and crankshaft turn at the same speed. Who is right? (A) A only. (B) B only. (C) Both A & B. (D) Neither A nor B. 4. The camshaft coordinates all of the following, EXCEPT: (A) intake valve opening. (B) injector opening. (C) injector pump operation. (D) exhaust valve opening. 5. Technician A says that a supercharger is driven off the engine while a turbocharger is driven by exhaust gases. Technician B says that turbochargers are more efficient than superchargers because they work hardest when engine speeds are higher and do not draw power from the engine to operate. Who is right? (A) A only. (B) B only. (C) Both A & B. (D) Neither A nor B. ASE-Type Questions 6. Technician A says most high-speed diesel engines now being manufactured use direct injection combus- tion chambers. Technician B says that indirect injec- tion using a precombustion chamber is the preferred method for most diesel engine manufacturers. Who is right? (A) A only. (B) B only. (C) Both A & B. (D) Neither A nor B. 7. Technician A says that horsepower is the ability to maintain a load at a desirable or fixed speed and is a measure of how fast work can be done. Technician B says that torque is a rotational or twisting force around a fixed point, and that the longer the stroke, the greater the amount of torque generated. Who is right? (A) A only. (B) B only. (C) Both A & B. (D) Neither A nor B. 8. A _______ is used to regulate the amount of fuel fed to the cylinders (A) rotor (B) plunger (C) rack (D) governor 9. All of the following takes place inside a unit injector, EXCEPT: (A) pressure to draw fuel from the tank. (B) injection timing. (C) fuel metering. (D) fuel atomization. 10. Technician A says that the exhaust manifold of diesel engines used in highway applications are usually cooled with engine coolant circulation. Technician B says that liquid-cooled manifolds may be used on marine applications. Who is right? (A) A only. (B) B only. (C) Both A & B. (D) Neither A nor B.