Synergy Quiz Btech Welcome to your Synergy Quiz btech Email Name 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 overlap crush lap or lead protrusion 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 quaker shaker circulation spray 3. The piston rod scraper box incorporated in a two-stroke/cycle, crosshead diesel engine serves to eliminate the necessity for an oil scraper ring prevent side thrust and cylinder scoring prevent sludge and dirty oil from entering the crankcase scrape oil and carbon deposits off the cylinder walls 4. In a large, slow-speed, main propulsion diesel engine, which of the parts listed is under tension when the engine is running? Bed plate Column Entablature Tie rod 5. The main advantage of unit injectors (combined fuel pump and injector) over other fuel injection systems is the lack of high pressure fuel lines their relatively low injection pressures reduced wear of spray orifices the lessened chance of fuel leaks into the engine sump 6. Passages are drilled in the crankshafts of diesel engines to provide lubricating oil to the main bearings connecting rod bearings piston pin bushings All of the above 7. When may the crankcase ventilation pipes or oil drain pipes of two or more engines be connected? Propulsion engines under 1000 shaft horsepower may share a common crankcase vent provided the oil drains remain separate. In most cases it is desirable and cost effective for propulsion engines to share a common crankcase ventilation and monitoring system. No interconnection may be made between the crankcase ventilation pipes or oil drain pipes. None of the above are correct. 8. The main function of tie rods in the construction of large, low speed diesel engines is to stiffen the bedplate in way of the main bearings to increase the engine's longitudinal strength accept most of the tensile loading that results from the firing forces developed during operation mount the engine frame securely to the hull to prevent shaft coupling misalignment connect the crosshead solidly to the piston rod 9. On most modern diesel engines, the main and connecting rod bearings receive their lubricating oil by banjo feed splash feed gravity feed pressure feed 10. Fuel injection pumps using the port and helix metering principle requires the use of a crosshatched design lapped plunger and barrel variable stroke variable cam lift 11. Lubricating oil is supplied to the crankpin bearings in a marine diesel engine by internal crankshaft passages immersion in oil spclearance lubrication injection lubrication 12. gudgeonpin bearings are difficult to lubricate because of their oscillating motion and their free-floating design their relatively small size the reciprocating motion of the piston their position in the lubrication system 13. The 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 one-half crankshaft speed in a two-stroke cycle diesel engine crankshaft speed in a two-stroke cycle diesel engine two times crankshaft speed in a two-stroke cycle diesel engine one-fourth times crankshaft speed in a four-stroke cycle diesel engine 14. Engines having a bore exceeding 250 mm, but not exceeding 300 mm are to have at least three compression rings per piston and the minimum of two oil scraper rings one intake and one exhaust valve per cylinder provided no other means of scavenging is used one explosion relief valve in way of each alternate crank throw, with a minimum of two valves one crankshaft except in cases where an opposed piston design is required 15. The opening of an exhaust valve on a modern, large, low- speed, main propulsion diesel engine, may be actuated by direct action of cam shaft compressed air pressure hydraulic "push rods" direct action of the main piston moving down 16. Shaker, circulation, and spray are the three general methods used in pre-injection fuel oil treatment lube oil filtration lube oil purification piston cooling 17. The speed of the camshaft in a two-stroke/cycle diesel engine, running at 950 RPM, is 475 RPM 950 RPM 1900 RPM 2400 RPM 18. Explosion relief valves on diesel engine crankcases should relieve the pressure at not more than 0.1 bar 0.2 bar 1.0 bar 2.0 bar 19. A 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 I only II only both I and II neither I nor II 20. The 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 ___________. bottom back top side
