13The camshaft drive is designed to maintain proper camshaft speed relative to crankshaft speed. In maintaining this relationship, the camshaft drive causes the camshaft to rotate at _____________.
A.one-half crankshaft speed in a two-stroke cycle diesel engine
B.crankshaft speed in a two-stroke cycle diesel engine
C.two times crankshaft speed in a two-stroke cycle diesel engine
D.one-fourth times crankshaft speed in a four-stroke cycle diesel engine
14Engines having a bore exceeding 250 mm, but not exceeding 300 mm are to have at least _________.
A.three compression rings per piston and the minimum of two oil scraper rings
B.one intake and one exhaust valve per cylinder provided no other means of scavenging is used
C.one explosion relief valve in way of each alternate crank throw, with a minimum of two valves
D.one crankshaft except in cases where an opposed piston design is required
15The opening of an exhaust valve on a modern, large, low- speed, main propulsion diesel engine, may be actuated by _____________.
A.direct action of cam shaft
B.compressed air pressure
C.hydraulic “push rods
D.direct action of the main piston moving down
16Shaker, circulation, and spray are the three general methods used in _____________.
A.pre-injection fuel oil treatment
B.lube oil filtration
C.lube oil purification
17The speed of the camshaft in a two-stroke/cycle diesel engine, running at 950 RPM, is _____________.
18Explosion relief valves on diesel engine crankcases should relieve the pressure at not more than _________.
19A two stroke diesel engine exhaust temperaturewill be lower than a four stroke diesel engine of the same displacement because the ___________. I. scavenging air is cooling the exhaust gases II. exhaust cycle time is longer
C.both I and II
D.neither I nor II
20The sealing surfaces of a diesel engine piston ring are considered to be the faces in contact with the cylinder wall, in addition to the ring groove ___________.
21.Where is the fuel delivery check valve located in a jerk pump fuel injection system?
A.In the cylinder head
B.On the suction side of the delivery pump
C.In the injection pump housing discharge
D.On the inlet side of the spray valves
22.How many crankcase relief valves are required for a 325mm bore, eight cylinder in-line engine?
23.Which of the air intake systems listed will result in the lowest specific fuel consumption?
24.In which of the following areas of a crosshead engine is a permanently connected fire extinguishing system required?
A.Exhaust manifolds in excess of eight inches in diameter.
B.Crankcases having a gross volume in excess of 21 cubic feet.
C.Turbocharger inlet piping in excess of twelve inches in diameter.
D.Scavenging spaces in open connection to the cylinders.