Piston Engine Design/Components

Question 1

Classification of engine

Answer 1

Number of cylinders
Arrangement
Method of cooling
Fuel type

Question 2

Liquid Cooling

Answer 2

Preferred method on A/C
Weight penalty
Maintenance issues

Question 3

Radial Engine

Answer 3

Cylinders arranged in circle around crankshaft

7-9 cylinders “leapfrog” 1,3,5,7,2,4,6 etc

Banks of arrangement of cylinders

• Hydraulicing - oil build up in inverted cylinder cause over stress pressure (*2 turn of rev of crankshaft)

Question 4

In Line Engine

Answer 4

Horizontal to reduce frontal load
- difficult to cool
- usually limited to 6 cylinders

Question 5

V Engine

Answer 5

Two in line engines set at angle
+ increase no of cylinder for same length

Question 6

Horizontally Opposed Engine

Answer 6

Short/rigid/most common design
Air cooled

Question 7

Barrel and Head

Answer 7

Head: Aluminium
Bottom: cast steel

Bolted together for gas tight seal

Cooling fins

Question 8

What is cast

Answer 8

Melting of metal and pouring to make a mould

Question 9

Spark Plugs

Answer 9

X2 in cylinder for redundancy/increased safety
Smoother/quicker/more efficient
Connected to magnetos

Question 10

Piston

Answer 10

Made of Aluminium
- Compression rings
- Connecting rods
- Gudgeon pin

Question 11

Crankshaft

Answer 11

Cast Steel
Heaviest component
Converts Linear motion to rotary motion

Question 12

Camshaft

Answer 12

Cast steel
Operate valves via push rods
Run parallel to crankshaft
Rotates at half speed of crankshaft

Question 13

Crankcase

Answer 13

Main structural element of engine
Light strong alloy magnesium
Provide mounting points

Crankshaft and camshaft located in crankcase

Question 14

Valves Operation

Answer 14

Opened by camshaft
Close under spring pressure
X 2 for preventing bounce/redundancy/smoothness

Question 15

Inlet vales properties

Answer 15

Stem - Smaller
Head - Bigger

Question 16

Exhaust Valve properties

Answer 16

Stem - Bigger
Head - Smaller

Hollowed and filled with sodium for heating

Question 17

Excessive valve clearance

Answer 17

Open too late and close early

Question 18

Insufficient valve clearance

Answer 18

Make contact early/close late

Question 19

What does tapper do

Answer 19

Ensure valve close at all temps

Too much clearance valve will open late and close early
Too little clearance valve will open early and close late

Reduction in performance

Question 20

Valve Gear

Answer 20

Collective name for pushrods/rockers

Question 21

Valves Made Of?

Answer 21

Steel Alloy

Question 22

Gudgeon Pin

Answer 22

Passes through the small end and the piston