Engine Technology Flashcards
Describe the actions needed for the engine to function?
Induction, Compression, Power and Exhaust
ICPE
The piston moves from top dead centre to bottom dead centre with the outlet open, then moves back with both valves closed. The power of the explosion then pushes back down, creating a force. The exhaust gasses are then expelled.
Why do we use oil in an engine?
We use oil to lubricate the moving parts and for cooling.
Which oil should be used in an engine?
Only the type the manufacturer recommends
Which type of cooling system do most vehicles have?
What temperature do they try and regulate the temperature to?
A sealed, liquid cooled system.
They try to regulate the engine temperature to 90-118c.
Without an engine cooling system, what would happen to the engine?
The cylinders would overheat, causing engine seizure through expansion.
What is an SI engine?
A petrol engine which uses spark plugs.
What is a CI engine?
A diesel engine which uses compression (it doesn’t have any spark plugs)
How do we ensure an engine runs efficiently?
We need the correct amount of fuel to be delivered at the correct time, in order to mix with the correct amount of air so the combustion can take place.
What is an ECU and what does it do?
The Engine Control Unit (ECU) is effectively the autopilot system of the engine, controlling things such as how much fuel is needed, the engine speed etc.
What percentage of emissions are harmful?
Catalytic converters are so good that only 0.8% of emissions are harmful.
What six purposes does an engine have?
- To convert chemical energy into mechanical energy
- To convert linear motion into rotary motion
- To provide rotational drive to propel the vehicle
- To propel the vehicle for long periods without failure
- To burn fuel efficiently
- To power the vehicle for up to 500,000 miles
