Engine Fundamentals

Question 1

What is Cylinder displacement?

Answer 1

Volume of cylinder at top dead center and volume at bottom dead center.

Question 2

What is compression ratio?

Answer 2

How much air/fuel mixture will be compressed at Top Dead Center (TDC) vs Bottom Dead Center (BDC).

Question 3

What is ‘Work’ ?

Answer 3

When force moves mass a specific distance.

Question 4

What is gear ratio?

Answer 4

Driving Gear over Driven Gear

Question 5

What is Horsepower?

Answer 5

The rate of which Torque is Produced

Question 6

Who first calculated Horsepower?

Answer 6

James Watt.

Question 7

What is the Atkinson Cycle?

Answer 7

It delays intake valve open to let mixture escape back into intake manifold.

Question 8

What are Intake Valves made up of?

Answer 8

Chrome, Nickle or Tungsten Steel.

Question 9

What are Exhaust Valves made up of?

Answer 9

Nichrome, Silicon-chromiun or Cobalt chromium Alloys.

Question 10

What does OHC mean?

Answer 10

Overhead Camshaft Engine.

Question 11

What are Main Caps?

Answer 11

They hold the main crankshaft bearings in place.

Question 12

What are the Piston Strokes in a 4-Stroke Engine?

Answer 12

Intake, Compression, Power and Exhaust.

Question 13

What is leakage past the piston rings called?

Answer 13

Blowby.

Question 14

What is Bearing Spread?

Answer 14

The parting face is slightly larger then the bearing bore.

Question 15

What is the best way to describe piston slap noise?

Answer 15

A Hollow Bell like noise.

Question 16

What test can be done to pinpoint the cause of a low cylinder compression?

Answer 16

Cylinder Leakage test.

Question 17

What is Piston slap?

Answer 17

Noise made by the piston when it contacts the cylinder wall.

Question 18

During a cylinder leakage test, where would you hear air if the Intake Valve is leaking?

Answer 18

Throttle Plate.

Question 19

During a cylinder leakage test, where would you hear air if the Piston Rings were worn?

Answer 19

The oil fill port or dipstick tube.

Question 20

During a cylinder leakage test, where would you hear air if the Exhaust valve was leaking?

Answer 20

Exhaust Pipe.

Question 21

During a cylinder leakage test, where would you hear air if the Head Gasket was blown?

Answer 21

Radiator.

Question 22

The Stroke of the Piston equal to ___ the Crankshaft Throw.

Answer 22

2x

Question 23

What is Thermal Efficiency?

Answer 23

How much of the heat formed during the combustion process is available as power from the engine.

Question 24

As an engine compression ratio increases, what should happen to the octane rating of the gasoline?

Answer 24

It should increase (to avoid detonation).

Question 25

What Engine type has the highest compression ratio?

Answer 25

Diesel Engine.

Question 26

What engine component is responsible for closing the intake and exhaust valves?

Answer 26

springs

Question 27

What is Tappet Noise?

Answer 27

Noisy Valvetrain Components.

Question 28

How many degrees of crankshaft rotation are required to complete a four-stroke cycle in one cylinder?

Answer 28

720

Question 29

Which V-type engine valve train design may use four camshafts?

Answer 29

DOHC

Question 30

SOHC V-8 engine has how many camshafts?

Answer 30

2

Question 31

When removing a cylinder head, which order should the bolts/nuts be loosened?

Answer 31

In the reverse order of assembly.

Question 32

what is the max allowable warpage on a V6 head?

Answer 32

0.003 inches.

Question 33

what is the max allowable warpage on a V8 head?

Answer 33

0.004 inches.

Question 34

what is the max allowable warpage on a I6 head?

Answer 34

0.006 inches.

Question 35

A free wheeling overhead camshaft engine is a _____________?

Answer 35

non-interference engine.

Question 36

What are Integral valve guides are reconditioned by?

Answer 36

Installing Bronze guide liners or by Reaming the guide (for an oversize valve stem).

Question 37

What is the typical interference angle used in gasoline engines?

Answer 37

1 degree.

Question 38

Multiple valve springs (dual springs) generally have both coils in what direction?

Answer 38

Wound in opposite directions.

Question 39

When should a valve be discarded?

Answer 39

When it has damaged keeper grooves, is cracked or bent.

Question 40

What is the cause for blue smoke that occurs after starting the engine?

Answer 40

worn valve seals or guides.

Question 41

Where should the piston be when a Cylinder Leakage Test is done?

Answer 41

Bottom Dead Centre on Exhaust Stroke.

Question 42

What 3 things should Valve Springs be checked for?

Answer 42

Tension, free height and squareness.

Question 43

Which Valve is larger?

Answer 43

Intake Valve.

Question 44

What Engine type does not have Pistons?

Answer 44

Rotary.

Question 45

Engine Displacement is measured in ________ .

Answer 45

CC or Liters.

Question 46

What is the Maximum Valve margin clearance?

Answer 46

1/32 of an inch.

Question 47

How much pressure does a Cylinder need to hold?

Answer 47

1000-1500psi

Question 48

What is the Formula for calculating displacement?

Answer 48

pie r2 (half the bore) X stroke X # of cylinders