oil system

Question 1

what are the five purposes of the oil system?

Answer 1

lubrication
sealing
cooling
cleaning
protection

Question 2

explain lubrication

Answer 2

oil provides slippery surface between moving parts to reduce friction

Question 3

explain sealing

Answer 3

provides a seal between the piston and cylinder to prevent expanding gases escaping

Question 4

explain cooling

Answer 4

cools by reducing friction
removes heat from cylinders through circulation of oil

Question 5

explain cleaning

Answer 5

carries away contaminants

Question 6

explain protection

Answer 6

prevents oxidisation by creating a thin film of protection

Question 7

what are the types of oil?

Answer 7

straight mineral oil (S)
ashless dispersant oil (W)

Question 8

should you mix different types of oil?

Answer 8

no

Question 9

what are the properties of straight mineral oil?

Answer 9

not the best lubricant
used for engines that have new parts to allow them to wear in
used for about 50 hours

Question 10

what are the properties of ashless dispersant oil?

Answer 10

great lubricator
can have additives that prevent corrosion etc.

Question 11

what are the grades of oil?

Answer 11

80 or 100

Question 12

what is grade of oil used decided by?

Answer 12

air temperature

Question 13

what does a higher grade number mean?

Answer 13

more viscous

Question 14

can you mix grades of oil?

Answer 14

yes, as long as its same type of oil

Question 15

what types of circulation is there?

Answer 15

dry sump and wet sump

Question 16

what is wet sump system?

Answer 16

oil collects at the bottom of the engine, where it cools before being recirculated

Question 17

what is dry sump system?

Answer 17

• a scavenge pump collects oil from lower parts of system and pumps oil back into oil tank
• then the oil pump takes oil from the tank and circulates it around

Question 18

what is an advantage of dry sump system?

Answer 18

provides means of having a larger oil supply for large engines

Question 19

what does the oil pump do?

Answer 19

takes oil from sump or oil tank and provides oil, at pressure, to the rest of the engine

Question 20

what does the oil filter do?

Answer 20

traps particles to clean it

Question 21

how does the oil cooler work?

Answer 21

cooled by airflow directed through small oil radiator

Question 22

what is the oil cooler pressure relief valve?

Answer 22

a valve that opens when pressure presented to it exceeds a certain value
- shortcuts the oil cooler

Question 23

where is the oil pressure sensor located?

Answer 23

on the high pressure side of the oil distribution system

Question 24

where is the oil pressure gauge located?

Answer 24

attached to the oil pressure sensor

Question 25

when should oil pressure be present?

Answer 25

rising within 30s

Question 26

what happens if there is no oil pressure?

Answer 26

engine will run for a few minutes, then seize and stop

Question 27

where is the oil temperature sensor located?

Answer 27

immediately after the oil cooler

Question 28

where is the oil temperature gauge located?

Answer 28

attached to the oil temperature sensor

Question 29

what does the oil pressure relief valve do?

Answer 29

regulates oil pressure, when activated by high pressure it vents high pressure oil to low pressure side