Engine Room Essentials: 20 Key Questions Answered
Why do we have tappet clearance?
For thermal clearance.
What does scavenge mean?
Using fresh air to remove spent gases.
Name two types of engine sensors and their operation.
Temperature and Pressure sensors.
TDC is used as a basis for what?
Reference point for exhaust inlet valves and fuel injection.
What does reduction mean with regard to a gearbox?
The use of a smaller gear to turn a larger one.
Explain the difference between 2-stroke and 4-stroke cycles.
A two-stroke engine is lighter, less efficient, and fuel lubricated.
What are the advantages of a V-form engine?
A V-engine is lighter, smaller, and more balanced.
What are the jobs of the camshaft and crankshaft?
The camshaft moves the valves, and the crankshaft transfers power from the pistons.
Viscosity:
Resistance to flow.
Name three contaminants in fuel.
Water, sediment, and growth.
Exhaust Smoke:
- White: Vapor (blown head gasket)
- Black: Rich mixture (clogged air filter)
- Blue: Oil burning (incorrect lubrication)
Marpol:
Marine Pollution Convention.
What are monthly maintenance considerations on a bilge pump?
Clean area, test switch and pump, check lines, hardware, and operation.
What procedure would you adapt to work on electricity?
Inform captain, isolate/signage, lock and tag, test equipment you are working on, and test the tester on a known source of supply.
What gas does a lead-acid battery produce?
Hydrogen.
What are your maintenance checks for batteries?
Test gravity, drop test tool, check condition and level.
Name two types of cathodic protection.
Impressed current and sacrificial anode cathodic protection.
Name three potential engine room fires.
Accidental discharge of fluids on hot surfaces, electrical fire due to loose connections, and improper flammable storage/disposal.
Describe how to bleed a fuel system.
Loosen the injectors, spin the wheel to allow diesel to come out by the injectors, then close injectors.
What is PPE?
Personal Protective Equipment.
How does a turbocharger work?
Two turbines are connected by a single input shaft, and the exhaust is released into the pistons with pressure.