- Explain the purpose of an air filter.
An air filter filters abrasive substances and some moisture from the air inlet. It also reduces air intake noise.
- What problems could you experience if you had a blocked air filter?
Engine will starve for air and revolutions will drop.
Exhaust may be smokey.
- Explain the reason for an Air Shutdown Valve.
To shut down the engine in the event of an overspeed.
Fuel and oil can still burn causing the engine to blow up, however this can be stopped by shutting off the air.
- What do ‘connecting rods’ do?
Connecting Rods connect the pistons to the crank journal.
- What is the purpose of the crankcase breather?
Crankcase breather allows the sump to ‘breathe’ and prevent a build up of pressure and heat.
- Explain what the ‘ crankshaft’ does.
The crankshaft is built at right angles to the shaft in order to convert reciprocating ( up and down) motion into rotary motion.
- Explain the purpose of the ‘flywheel’.
The flywheel carts the engine over the non power strokes and absorbs and smoothes out the engine running during intermittent power strokes.
- Explain the purpose of the ‘fuel injection pump’.
The fuel injection pump pumps fuel into the engine under pressure. The pump is directly connected to the fuel injectors and in conjunction with the Governor, it accurately measures the amount of fuel required.
- Explain the purpose of “sacrificial anodes”.
Sacrificial anodes are small zinc devices strategically placed in the cooling system and other locations (I.e. near shaft and rudder fittings) that are designed to prevent internal corrosion of a marine diesel engine. They work by dissolving, oxidising and attracting particles.
- What is the purpose of a thermostat.
The thermostat is a heat sensitive valve that controls the flow of water in the cooling system. It remains shut on start up to allow an engine to reach normal operating temperature quickly.
