Diesel Engines Updated Questions And Answers

B - ANS Based on ABYC standards, minimum spacing between hull vent openings and fuel fill or vent fittings should be: A. 9 inches B. 15 inches C. 24 inches D. 36 inches D - ANS The thermal efficiency of a diesel engine is such that typical heat converted to useful power is approximately _______% of the total heat A. 22 B. 45 C. 15 D. 36 A - ANS One of the primary differences between the gasoline-filed engine four stroke cycle and the diesel four-stroke cycle is: A. the intake stroke only brings air into the cylinder B. The compression ratio of the diesel engine is much lower than the same sized gasoline engine C. Fuel gets atomized by the high heat with a diesel engine D. The diesel fuel is more volatile than the gasoline C - ANS Temperature controlled engine room exhaust blowers in diesel powered boat are primarily used to: A. heat the boats cabin B. ventilate the boats fire suppression system C. lower engine room temperatures D. reduce exhaust back pressure B - ANS With some diesels there may be a need to ________ incoming air to the combustion chambers to assist in cold starting A. Pressurize B. heat C. humidify D. atomize D - ANS In setting up a piping system for exhaust gasses, the number of sharp bends should be kept to a minimum to A. raise exhaust gas temperature B. permit use of a larger diameter pipe C. eliminate the need for a silencer D. prevent excessive exhaust back-pressure D - ANS Which of the following does not have requirements that apply to exhaust components and hose types? A. UL 1129 B. SAE J2006 C. ABYC P-1 D. US Coast Guard A - ANS Which of the following is the most likely exhaust related cause for excessive engine operating temperature? A. exhaust elbows that are old and clogged B. delaminated exhaust hose C. oversized exhaust system D. underwater exhaust outlet C - ANS An engine equipped with an exhaust-mixing elbow is installed below the waterline. What device must be installed in the raw water discharge hose ahead of the mixing elbow. A. manometer B. Flow diverter C. siphon break D. flapper valve A - ANS Upon inspection of the wet exhaust system. The tech notices that the exhaust hose is burned near the elbow. Tech A says that replacing the hose will correct the problem. Tech B says that the problem is most likely with the cooling system. Which tech is correct? A. Tech B B. Tech A C. Both Techs are correct D. Neither Tech is correct A - ANS If you do not refill the raw water system with a winterizing solution for long-term storage after draining the seawater, the system is prone to: A. oxidation B. freezing C. overheating D. A and C C - ANS Replacement of a failed seawater pump impeller should normally include: A. draining water lift muffler B. flushing heat exchanger C. checking all downstream components for impeller pieces D. replacing zinc anodes C - ANS During a sea trial for a complaint of high speed overheating, the technician finds that the cooling hoses are swollen and very firm when squeezed and the exhaust hoses very hot to the touch. This most likely indicates: A. the raw water pump is ingesting air with the seawater B. the exhaust diameter is too small C. the exhaust manifold or risers are blocked D. the exhaust outlet at the stern is blocked B - ANS tech A says that you must observe USCG regulations when choosing and installing seacocks. Tech B says there is no standard for seacocks or their installation. Which Tech is correct. A. Tech A B. Tech B C. Both techs are correct D. Neither tech is correct D - ANS During engine operation a tech notices that the water level is low in the seawater strainer. This might indicate which of the following? A. the seawater strainer has an air leak B. seawater impeller is incorrect C. seawater inlet problem D. both A and C E. both B and C D - ANS The most common cause of low coolant temperature in a closed cooling system is: