202C - Lubrication & Crankcase Ventilation Flashcards
Good quality oil will serve what four main functions?
- Reduce wear & friction
- Clean
- Absorb heat
- Act as a sealant
202C pg. 2
What is viscosity a measure of?
Resistance to flow.
202C pg. 3
What does the viscosity index (VI) refer to?
The rate that oils will change viscosity as the temperature changes.
A small change in viscosity through various temperatures is a high VI.
202C pg. 5
What term describes the rate that oil viscosity changes with temperature?
Viscosity Index (VI)
Low VI = High viscosity change
High VI = Low viscosity change
202C pg. 5
What is oil pour point?
The lowest temperature at which the oil will flow.
202C pg. 6
Would 5W30 or 0W30 oil have a lower pour point and be better suited for colder temperature usage?
0W30
Pour point of -48C
202C pg. 6
What are detergents designed to do as part of an oil additive?
Prevent deposits from forming on internal engine parts by keeping particles in suspension.
202C pg. 7
What are dispersants designed to do as part of an oil additive?
Keep deposits suspended in the oil.
202C pg. 7
What do the two types of oil classifications SI and CI represent?
SI - Spark Ignition
CI - Compression Ignition
202C pg. 8
The majority of bearing failures can be traced to _______ caused by ______.
Traced to oil contamination
Caused by dirt in the lubricant
202C pg. 10
How should the oil sample be taken?
- When the oil is hot and wear particles are still in suspension
- Mid-stream
202C pg. 13
An oil analysis serves what two main purposes?
- Determines the suitability of the oil
- Determine if there are any existing engine problems
202C pg. 14
The engine crankcase is used to _____ and ______ the supply of lubricating oil.
- Store
- Cool
202C pg. 21
What materials are engine oil pans typically constructed of?
- Steel sheet metal
- Aluminum
202C pg. 22
The two most common designs of engine oil pumps are:
- External gear type
- Rotor style
202C pg. 25
What maintains the system oil pressure within normal operating limits?
Oil pressure regulating valve
202C pg. 27
What is used to protect the engine from excess oil pressure?
Oil pressure relief valves
202C pg. 28
If both an oil pressure regulating valve and relief valve are used, which valve will have the higher pressure setting?
Relief valve will have the higher pressure setting.
202C pg. 28
What are the two main types of oil coolers?
- Oil to air
- Oil to coolant
Used to reduce chance of oil oxidation and breakdown.
202C pg. 29
What is the purpose of the oil bypass filter?
- Receives 5% - 10% of the engine’s oil to filter and return to oil pan
- Used strictly as a cleaning device
- May trap particles down to 10 microns
There is no bypass valve in a bypass filter.
202C pg. 31
What is the purpose of the full-flow oil filter?
- Filters all the oil for engine lubrication
- Filters between 25-60 microns
- Has a bypass valve
202C pg. 32
When the bypass valve is open, the full-flow oil filter becomes a _____, delivering both filtered and unfiltered oil.
Shunt type oil filter
202C pg. 32
What is the main purpose of the crankcase ventilation system?
Removes combustion gases and water vapours from the crankcase.
If blow-by gases were to remain in the crankcase, the chance of forming sulphuric acid in the oil increases.
202C pg. 35
What will form in the engine if the engine rarely warms up sufficiently to transmit water vapours to the crankcase ventilation system?
Sludge will form
202C pg. 36
