Crankshaft Assembly and Pistons D2L

Question 1

What journals on the crankshaft support the crankshaft and allow it to rotate with minimal friction?

Answer 1

Main Journals

Question 2

What type of vibration dampener can be serviced or have components replaced?

Answer 2

Spring Type

Question 3

What is the angle of separation of the throws on the crankshaft of a four stroke inline 8 cylinder engine?

Answer 3

90 degrees
720/8 = 90

Question 4

If an engine was to be driving a fire pump, what component would the pump shaft connect directly to?

Answer 4

The flywheel
(drive end)

Question 5

What bearing material property describes the ability for the bearing material to mould itself to the shape and imperfections of the journal?

Answer 5

Comformability
- the ability of the bearing to mould itself to the imperfections of the crank journal.

Question 6

True or False;
Bearing spread ensures the bearing shell will stay in place during installation

Answer 6

True

Question 7

True or False;
Do not touch the bearing surfaces with your bare finger tips because the oils from them could cause etching of the bearing surface.

Answer 7

True
keep your dirty dick fingers off em.

Question 8

Name 2 conditions that would indicate that a vibration dampener would need to be replaced.

Answer 8

• If the rubber becomes oil soak or torn
  -After the specified service life determined by the manufacturer

Question 9

What method of torquing fasteners is the most accurate way to preload a fastener?

Answer 9

Elongation method

Question 10

What is one of the reasons for pistons having irregularly shaped tops?

Answer 10

To create turbulence within the cylinder to help mix the fuel and air

Question 11

What are the types of wrist pins used in engines.

Answer 11

Locked to Rod
Full Floating - most common
Semi-Floating

Question 12

What method of piston cooling and lubrication is commonly used on high speed engines?

Answer 12

Spray nozzle

Question 13

Using the rule of thumb for the piston ring end gap, determine the end gap required for a cylinder with a bore of 6.5 inches.

Answer 13

19.5 - 32.3 mils
6.5 x 0.003 = 19.5
6.5 x 0.005 = 32.5

0.003 to 0.005 mils per inch of bore diameter

Question 14

If a piston ring has inadequate side clearance, what would happen?

Answer 14

Ring seizure in the piston

Question 15

Select the true statement regarding piston rings.
A) Oil rings increase their sealing ability as the cylinder pressure increases
B) Only use chrome-faced rings in chrome plated liners
C) External chamfers should face the top of the piston
D) Internal chamfers should face the top of the piston

Answer 15

D) Internal chamfers should face the top of the piston

Question 16

True or False;
One of the purpose of piston rings is to help to dissipate the heat from the piston into the cylinder walls.

Answer 16

True

Question 17

True or False;
When installing a piston into the cylinder, if it becomes hung up or jammed, hammer it harder to ensure it seats the piston rings into the cylinder as they are an interference fit.

Answer 17

False