Engineering, Control Systems. Test 25

A Main Engine revolution counter reads 69,980 at 0800; at noon the counter reads 90,932, if the clocks are advanced 20 mins. during the watch what was the average rpm during the 8-12 watch?

77.2 rpm
87.3 rpm
115.6 rpm
98.4 rpm

A piston of this type is composed of the following main parts:-

piston, piston rings, telescopic piping.
piston crown, piston rod, piston skirt, intermediate piece.
piston body, piston flange, piston crown.
piston crown, piston body, piston rings.

What would you call the assembly fitted on the piston rod, which fits into a flange on top of the crankcase block opening through which the piston rod moves in order to secure tightness ?

The piston underside valves.
The scavenging air valve box.
The piston rod stuffing box.
The crankcase sealing assembly.

What is the best way of preventing scavenge fires in a slow speed two stroke diesel?

Burn only the specified grade of fuel.
Maintain correct cylinder lubrication.
Ensure fuel injectors are maintained.
Keep scavenge spaces clean.

For a turbo charger is running at full speed, what would be a usual oil sump temperature on the turbine side ?

35 to 45 degrees C
55 to 65 degrees C
72 to 82 degrees C
45 to 50 degrees C

What would result from high charge air temperatures?

Charge pressure would increase.
Jacket water temperature would rise.
Cylinder head relief valves would lift.
All exhaust temperatures would rise.

In a 4 cycle engine the inlet valve begins to open when the piston is _____

after TDC on the suction stroke.
just before TDC on the exhaust stroke.
at BDC on the firing stroke.
just before BDC on the suction stroke.

At what moment will the cylinder head starting air valve, shown here, open and allow 25 bar to flow into the cylinder ?

When the main starting air is opened from the bottle.
When the control air on top is vented by the starting cam.
When control air is supplied to the top connection.
When 25 kg/cm2 air is supplied on top by manoeuvring.

Review Answers