engines

Question 1

breakdown of air

Answer 1

78% nitrogen
21% oxygen
1% other gasses

Question 2

breakdown of petrol

Answer 2

16% hydrogen

84% carbon

Question 3

breakdown of diesel

Answer 3

87% carbon
11% hydrogen
1% sulphur
1% oxygen

Question 4

Air bubbles in the coolant system caused by =

Answer 4

Defective cylinder head gasket-

allows air from combustion chamber through to the coolant system

Question 5

Too much valve clearance =

Answer 5

Valves open too late - do not open fully

Question 6

How do you measure the gap between piston rings and the cylinder?

Answer 6

feeler blades

Question 7

what would a oil preassure relief seal that is faults/not seated properly cause?

Answer 7

low oil preassure

Question 8

Advantages of compression ignition engines over spark ignition engines

Answer 8

Lower fuel consumption
Reduced fire risk
longer operational life

Question 9

Distance from tdc to bdc

Answer 9

stroke

Question 10

number of camshaft revelutions during one 4 stroke cycle

Answer 10

2

Question 11

number of camshaft revelutions during one 2 stroke cycle

Answer 11

1

Question 12

what does ohv engine stand for?

Answer 12

overhead valve

Question 13

as the piston moves down in the induction stroke, what pushes the air into the cylinder?

Answer 13

atmospheric preassure

Question 14

what does ohc stand for?

Answer 14

overhead cam

Question 15

what does cih stand for?

Answer 15

cam in head

Question 16

correct air:fuel ratio for burning fuel?

Answer 16

14.7:1

Question 17

what is valve overlap?

a) The time when both valves are closed?
b) The time when both valves are open?

Answer 17

b) when both valves are open?

Question 18

in the 4 stroke cycle, the piston is moving down with both valves closed, what stroke is this?

Answer 18

power

Question 19

engines fitted across the axis of the vehicle are known as?

Answer 19

transverse

Question 20

what is total loss lubrication?

Answer 20

when the oil is mixed with the petrol, and is burned

Question 21

what valves are open on the induction stroke?

Answer 21

inlet valve

Question 22

what valve is open on the exhaust stroke

Answer 22

exhaust valve