9
Contents
Crankshaft 110
Crankshaft Main Bearings 111
Crankcase Seals 112
Pistons 112
Piston Construction 113
Piston Thrust Surfaces 114
Piston Head Size 114
Piston Head Shape 114
Piston Rings 115
Piston Ring Types 115
Piston Ring Construction 118
Ring Tension 118
Ring Movement 118
Piston Pins 118
Connecting Rods and Bearings 120
Friction-Type Rod Bearings 120
Antifriction Bearings 121
Intake and Exhaust Ports 121
Ports, Reed Valves, and Rotary Valves 122
Poppet Valves 123
Camshafts and Gears 125
Valve Lifter or Tappet 126
Valve Train Confi gurations 127
Starter Assembly 127
Automatic Compression Release 128
Flywheel 130
C H A P T E R 7
Measuring Engine Performance
133
The Engine 133
Basic Terminology 135
Engine Bore and Stroke 135
Science of Engine Performance 135
Energy 135
Force 136
Pressure 137
Work 137
Power 138
Torque 139
Measurements of Engine Performance 141
Engine Displacement 142
Compression Ratio 142
Engine Horsepower 142
Engine Torque 147
Torque and Horsepower 147
Volumetric Effi ciency 148
Practical Effi ciency 148
Mechanical Effi ciency 149
Thermal Effi ciency 149
S E C T I O N 3
Engine Systems
C H A P T E R 8
Fuel Supply, Air Induction, and
Emissions
153
Engine Fuels 153
Gasoline 153
Liquefi ed Petroleum Gas and Natural Gas 155
Kerosene and Diesel Fuels 156
Fuel Systems 156
Fuel Tanks 156
Fuel Lines and Fittings 157
Fuel Filters 157
Fuel Pumps 157
Pressurized Fuel System 160
Vapor Return Fuel Systems 161
Air Induction Systems 161
Air Cleaners and Air Filters 162
Crankcase Breathers 165
Muffl ers 166
Emissions 167
Emission Control Regulations 167
C H A P T E R 9
Carburetion
173
Principles of Carburetion 173
Air-Fuel Mixture 174
Carburetor Pressure Differences 174
Types of Carburetors 176
Float-Type Carburetors 176
Diaphragm-Type Carburetors 182
Vacuum Carburetors 185
Primers 186
Manual Throttle Controls 186
S E C T I O N 3
Engine Systems