- What is meant by internal combustion?
The fuel is burnt inside the engine’s cylinder.
- Name the four strokes of the Otto cycle.
Power stroke and
- How can you identify the inlet valve from the exhaust valve on a particular engine?
The inlet valve/valves has a larger head than exhaust.
What is the speed of the camshaft compared with that that of the crankshaft?
- What is meant by the term Valve overlap?
Both valves open together.
- What is meant by the Swept volume of an engine?
It is the volume of a cylinder between Top dead center (T.D.C) and Bottom dead center (B.D.C), multiplied by the number of cylinder.
- What determines the stroke of an engine?
It is twice the crank radius.
- Why must there nomally be a clearance between the end of a valve and its operating mechanism?
To allow for expansion of the valve due to heat.
- What is most common method of driving the camshaft on modern light vehicle engine?
A toothed belt
- Why are multiple cylinders used instead of a single large cylinder?
Uneven torque, a large flywheel and heavy weight make the single cylinder engine unsuitable.
- State the major operating difference between two-stroke engines.
The operating cycle takes one revolution of the crankshaft on a two-stroke and two revolution on a four-stroke.
- Give the meaning of the term of crankcase compression.
It is one method of compressing the fresh charge of mixture on a two-stroke engine before transferring it to the cylinder.
- What is the probable cause of bubbles in the coolant when carrying out a cylinder leakage test?
Cylinder head gasket allowing leakage into the cooling system.