Mazda Training manual - part 228

 
CONTENTS 

 

page i

Piston Engine Fundamentals

TC010-05-01S

1 – INTRODUCTION ............................................................................ 1

 

Course Overview .................................................................................. 1 

Audience and Purpose................................................................... 1 
Course Content and Objectives   ................................................. 2 
 

How to Use This Guide ......................................................................... 3 

Section Objectives ......................................................................... 3 
Text and Illustrations...................................................................... 3 
Review Exercises .......................................................................... 4 

 

 

 

2 – BASIC OPERATION....................................................................... 5

 

Objectives ............................................................................................. 5 
How Power is Developed ...................................................................... 6 

Harnessing Power.......................................................................... 6 
Controlling Combustion.................................................................. 7 

The Four-Stroke Cycle.......................................................................... 9 

Intake Stroke................................................................................ 10 
Compression Stroke .................................................................... 11 
Power Stroke ............................................................................... 11 
Exhaust Stroke ............................................................................ 11 
Summary ..................................................................................... 12 

Review Exercise 1 .............................................................................. 12 
Basic Design Characteristics .............................................................. 13 

Cylinder Configuration ................................................................. 14 
Valve Train Type.......................................................................... 15 
Bore, Stroke, and Displacement .................................................. 17 
Compression Ratio ...................................................................... 18 

Engine Components and Systems...................................................... 19 
Review Exercise 2 .............................................................................. 19 

 

 

 
CONTENTS 

 

page ii

Piston Engine Fundamentals

TC010-05-01S

3 – SHORT BLOCK............................................................................ 21

 

Objectives ........................................................................................... 21 
Overview ............................................................................................. 22 
Cylinder Block ..................................................................................... 23 

Construction................................................................................. 24 
Crankcase.................................................................................... 24 
Crankshaft Main Supports and Bearings ..................................... 24 

Crankshaft........................................................................................... 25 

Features....................................................................................... 26 
Construction................................................................................. 27 
Number of Journals...................................................................... 28 
Vibration Damper......................................................................... 28 

Main Bearings ..................................................................................... 29 

Lubrication ................................................................................... 30 
Clearance .................................................................................... 31 
Thrust Bearings ........................................................................... 32 

Review Exercise 3 .............................................................................. 32 
Connecting Rods ................................................................................ 34 

Construction................................................................................. 35 
Cylinder Wall Lubrication ............................................................. 35 

Pistons ................................................................................................ 36 

Construction.................................................................................  
Clearance .................................................................................... 37 

Piston Rings........................................................................................ 39 

Compression Rings...................................................................... 40 
Oil Rings ...................................................................................... 41 

Review Exercise 4 .............................................................................. 42 

 

 

 
4 – VALVE TRAIN .............................................................................. 43

 

Objectives ........................................................................................... 43 
Cylinder Head ..................................................................................... 44 

Construction................................................................................. 44 
Sealing......................................................................................... 45 

Valves ................................................................................................. 46 

Components ................................................................................ 46 
Construction................................................................................. 47 
Multi-Valve Design ....................................................................... 47 

Valve Seats......................................................................................... 48 
Valve Guides....................................................................................... 49 

 

 

 
CONTENTS 

 

page iii

Piston Engine Fundamentals

TC010-05-01S

Valve Springs...................................................................................... 50 

Construction................................................................................. 51 
Spring Tension............................................................................. 51 
Working Height ............................................................................ 51 

Overhead Valve Train ......................................................................... 52 
Overhead Cam Valve Train................................................................. 53 

Overhead Cam (OHC or SOHC).................................................. 53 
Dual Overhead Cam (DOHC) ...................................................... 55 

Camshaft Drives ................................................................................. 55 

OHV Drive.................................................................................... 56 
Chain Adjuster ............................................................................. 57 
OHC Drive ................................................................................... 58 
Timing Belt Auto Tensioner.......................................................... 59 
Belt and Chain Drive .................................................................... 60 
Gear-Driven Camshaft with Friction Gear .................................... 61 

Camshaft Design ................................................................................ 62 

Auxiliary Drives ............................................................................ 63 
Lubrication ................................................................................... 63 
Camshaft Measurements............................................................. 63 

Review Exercise 5 .............................................................................. 64 
Valve Adjustment ................................................................................ 65 

Valve Clearance .......................................................................... 65 

Hydraulic Lash Adjusters (HLA) .......................................................... 66 

Description and Operation ........................................................... 66 
Bucket-Type HLA......................................................................... 67 
Rocker Arm-Mounted HLA........................................................... 68 
Regular Oil Changes.................................................................... 68 

Pushrods (OHV).................................................................................. 69 
Rocker Arms ....................................................................................... 69 
Review Exercise 6 .............................................................................. 70 

 
 

5 – LUBRICATION SYSTEM.............................................................. 71

 

Objectives ........................................................................................... 71 
System Components........................................................................... 72 

Oil Pan ......................................................................................... 73 
Oil Strainer (Pick-Up) ................................................................... 73 
Oil Pump ...................................................................................... 73 
Oil Filter ....................................................................................... 73 
Oil Seals ...................................................................................... 74 
Dipstick ........................................................................................ 74 
Oil Pressure Indicator .................................................................. 74 

How Oil Circulates .............................................................................. 75 

 

 
CONTENTS 

 

page iv

Piston Engine Fundamentals

TC010-05-01S

Pressure Lubrication ........................................................................... 76 
Oil Pumps ........................................................................................... 77 

Pressure Relief Valve .................................................................. 77 
Rotor-Type Pump (Trochoid) ....................................................... 78 
Gear Pump .................................................................................. 79 

Oil Filter............................................................................................... 80 

Bypass Valve ............................................................................... 80 
Anti-Drainback Diaphragm........................................................... 81 

Sealing Materials ................................................................................ 81 
Review Exercise 7 .............................................................................. 82 

 

 

 

6 – COOLING SYSTEM...................................................................... 83

 

Objectives ........................................................................................... 83 
Components........................................................................................ 84 

Coolant ........................................................................................ 84 
Water Pump................................................................................. 85 
Coolant Passages........................................................................ 85 
Thermostat................................................................................... 85 
Radiator Reservoir ....................................................................... 85 
Fan............................................................................................... 85 
Pressure Cap............................................................................... 85 
Radiator ....................................................................................... 85 

How Coolant Circulates....................................................................... 86 
Water Pumps ...................................................................................... 87 

Impeller-Type Pump..................................................................... 87 
Centrifugal Operation................................................................... 88 

Review Exercise 8 .............................................................................. 89 
Radiators............................................................................................. 90 

Downflow-Type ............................................................................ 90 
Crossflow-Type............................................................................ 91 
Radiator Reservoir ....................................................................... 92 

Pressure Cap ...................................................................................... 92 
Thermostat.......................................................................................... 94 
Fan Drives........................................................................................... 95 

Viscous Drive Clutch.................................................................... 96 

Review Exercise 9 .............................................................................. 97 

 

 

 

7 – GLOSSARY.................................................................................. 99