Main Diesel Engine -Design Components


Main Diesel Engine-Design Components

1.Precision engine bearing inserts are manufactured with a small portion of the bearing ends extending beyond the bearing housing or caps. The installation process of these bearings requires sufficient ________.



C.lap or lead



2.The method of piston cooling in which oil is delivered through the connecting rod to a compartment within the piston, then distributed by the motion of the pistons, and allowed to drain to the crankcase via one or more holes or pipes, is termed ________






3The piston rod scraper box incorporated in a two-stroke/cycle, crosshead diesel engine serves to _____________.
A.eliminate the necessity for an oil scraper ring

B.prevent side thrust and cylinder scoring

C.prevent sludge and dirty oil from entering the crankcase

D.scrape oil and carbon deposits off the cylinder walls


4In a large, slow-speed, main propulsion diesel engine, which of the parts listed is under tension when the engine is running?

A.Bed plate



D.Tie rod


5The main advantage of unit injectors (combined fuel pump and injector) over other fuel injection systems is _____________.
A.the lack of high pressure fuel lines

B.their relatively low injection pressures

C.reduced wear of spray orifices

D.the lessened chance of fuel leaks into the engine sump


6Passages are drilled in the crankshafts of diesel engines to provide lubricating oil to the _____________.

A.main bearings

B.connecting rod bearings

C.piston pin bushings

D.All of the above


7When may the crankcase ventilation pipes or oil drain pipes of two or more engines be connected?

A.Propulsion engines under 1000 shaft horsepower may share a common crankcase vent provided the oil drains remain separate

B.In most cases it is desirable and cost effective for propulsion engines to share a common crankcase ventilation and monitoring system

C.No interconnection may be made between the crankcase ventilation pipes or oil drain pipes

D.None of the above are correct.


8The main function of tie rods in the construction of large, low speed diesel engines is to ____________.

A.stiffen the bedplate in way of the main bearings to increase the engine’s longitudinal strength

B.accept most of the tensile loading that results from the firing forces developed during operation

C.mount the engine frame securely to the hull to prevent shaft coupling misalignment

D.connect the crosshead solidly to the piston rod


9On most modern diesel engines, the main and connecting rod bearings receive their lubricating oil by ____________.

A.banjo feed

B.splash feed

C.gravity feed

D.pressure feed


10Fuel injection pumps using the port and helix metering principle requires the use of a ___________.

A.crosshatched design

B.lapped plunger and barrel

C.variable stroke

D.variable cam lift


11Lubricating oil is supplied to the crankpin bearings in a marine diesel engine by _____________.

A.internal crankshaft passages

B.immersion in oil

C.spclearance lubrication

D.injection lubrication


12gudgeonpin bearings are difficult to lubricate because of their oscillating motion and _____________.

A.their free-floating design

B.their relatively small size

C.the reciprocating motion of the piston

D.their position in the lubrication system